What does a stock 560 SEL do in the 1/4 mile? - Auto-Trend Repairs and Service Information Forums

Rastus · UNSTOPPABLE!

RE: What does a stock 560 SEL do in the 1/4 mile?

stoma · Member

FUCK MAN!!!!!!!!!!! ALL THAT BULLSHIT WRITTEN BY THAT PUNK ASS BITCH RASTUS PUT ME TO SLEEP!!!!!!!!!!! FUCKIN CANT MAKE IT PAST 3 LINES BEFORE MY EYES GET ALL HEAVY!!!!!!!!!!

QUIT POSTIN SHIT RASTUS BETTER YET.GET THE FUCK OUT OF THIS FORUM CAWKSUCKKAAAAA!!!!!!!!!!!!!!!!!!!!!!!!!

Rastus · UNSTOPPABLE!

Hello folks,

So since we now know a little more about our crankshafts & its bearings, what do the machine-shop specialists actually do to find other defects, & how do they go about repairing the shaft back into a service-able state ?

CRANKSHAFT INSPECTION & REPAIR

As engine crankshafts are usually large & expensive parts, it's often a better option to have them repaired where possible than replaced. Before any extensive work is carried out however, it is well to have the shaft inspected / checked by a specialist with proper magnetic, or chemical equipment to ensure that there are no invisible cracks in it.

Magnetic indicators = Where the use of a fine metal powder is applied to the shaft / journals, then when magnetized, the powder localizes within the cracks to reveal the damage.

Chemical indicators = Where the application of a special chemical to the shaft / journals will reveal the invisible cracks when viewed with special glasses & UV light.

Our crankshafts are exposed / subjected to terrific vibration & stress, & may develop tiny cracks, particularly at or near the ends of the con-rod throws, or at the ends of the main bearing journals. Occasionally, an invisible crack may develop near the oil-feed holes in the shaft.

If the crankshaft is sound, & the journals are worn slightly tapered or out-of-round, the shaft journals can be re-ground & under-size bearings fitted. Should the shaft be badly damaged, it is possible ( though NOT recommended for high-performance use ) to restore the journal by using a special technique where-by metal can actually be "sprayed" onto the shaft until it's over-size, & then reground back to specification.

Cheers,

Rastus

Rastus · UNSTOPPABLE!

Yo people,

We always hear things about cranks needing machining, rods needing aligning etc etc. But how & why do things wear, & what is actually done to repair them ? If I have your interest, read on....

CRANKSHAFT WEAR

It should be understood that there are forces applied to your crankshaft-journals ( big-end & mains ) that are much "heavier" at some points of rotation than others. To elaborate, the force produced during combustion is several-times as strong as when compared to the compression-stroke. Also, the power-stroke applies the force pretty-much always at the same spot of the journal. There is also the action of centrifugal force resulting from the rotation of the crankshaft with its con-rods & pistons. The result is an out-of-round condition forms on the crankshaft journals & crank-pins.

If a con-rod is bent, or is out of alignment, it will tend to wear the crank-journal in a tapered fashion, - that is, more at one-end of the bearing surface-face than the other end. Also, any twisting of the engine crank-case or any excessive vibration of the crankshaft will tend to cause the main-journals to wear in a tapered form.

Should abrasive material get into the oil, the wear may be unequal, more at one-bearing or more at one-spot of the bearing depending on which bearing, & where on the bearing the abrasive enters in greatest quantities. Bearings seldom wear equally for these & other reasons. One bearing may operate with a smaller volume of oil than another-one. Likewise, due to its location in the engine, may operate at a higher temperature than the others. All of these things contribute to unequal wear on your crankshaft journals.

If a con-rod journal has even the least taper, or signs of a flat-spot, it simply cannot be used. Typically, such a condition would actually cause an increase in oil-consumption, audible knocking, excess damage etc, so hence, machining of the journal(s) would need to be completed. Due to close tolerances in the bearings, a "sprung" crankshaft simply cannot be used. The main-bearings must fit the crankshaft journals all around the circumference with only the correct amount of clearance for a film of lubricating oil. If the bearing journal is scored or other than completely round, it cannot be used until its machined or replaced.

As further food-for thought, you may ask why typically the upper bearing in your con-rod tends to wear a little more than the lower half, it's because it's subjected to more continual forces than the lower half...In fact the lower half only sees greater loading during the intake stroke...This may also explain to some of you why often you see an oil-groove for the upper con-rod bearing shell, & not the lower.

More next time...

Cheers,

Rastus

Rastus · UNSTOPPABLE!

Hello people,

At this stage of the "posting", it 's probably a good time to simplify the things that we should be looking out for, and explain why all this is possible for you to do yourself, especially if you actually own a Mercedes.

* By determining the current state of your bores & pistons, you can re-fresh ( & improve ) the performance & extend the operating life of your engine at a very much reduced cost.

* Ensuring that all the measurements of your crankshaft & bearings are correct is an insurance policy to the long-term continued performance & reliability of your bottom end.

* The free running check of your bottom-end tells you the potential of how much "hidden"extra power you've released to be transfered to your fly-wheel by identifying, rectifying, & then improving on the assemly. Don't have your oil-seals in place when doing these checks !

* Your engine's bottom end is now possibly & quite likely more reliable than the day it first left the factory.

* Reduced friction = more power + more reliability + longer component life.

* Your Mercedes Benz cylinder heads are already pretty much optimized from the factory and are in great shape ! In reality there's very little to do except replace the normal wearing parts if needed, and machine the valves and seats back up to the standard 3-angles as from the factory. When this work has been carried out by a work-shop, pull the valves back out of the head & make sure they've done what you've asked for ! You'll find that the cost of reconditioning your heads will be by far the most expensive part of this freshen up, so it's worth knowing that you got what you paid for !

* Mercedes engines are made already to a very very high standard, which does make life for us heaps better, since we don't have to pay for the extra special things to get modified because they don't need to be ! However, it is a production assembly line, & this means that the clock is the real boss ! You yourself can take as much time as you like, & can possibly improve on something already very excellent.

* Remember to blow out every hole in the block with compressed-air to remove any stray pieces of metal that may be in there after any machining has been carried out.

* When you finally get around for that final re-assembly of the bottom-end, apply as much oil as possible into every hole you find in your crank, block & rods, to ensure that your new parts are not waiting for oil when you go to first start-up. Expect to be able to put well over a litre just into these holes etc to fill them up. Also, disconnect your ignition on first start-up until you have oil-pressure reading on your gauge whilst you crank. Once your oil-pressure is established, then you can start your engine !

* Your oil-pump is probably the most important component in your engine assemly. Do I need to explain what's needed here ? Make sure that it's well primed on assembly. A light smear of vaseline or light moly-grease or engine honey (STP) on the gear-teeth and housing will guarantee suction & pressure when you first go to crank.

All the best and enjoy yourselves !

Rastus

-- Edited by Rastus on Thursday 30th of May 2013 11:23:29 PM

-- Edited by Rastus on Thursday 30th of May 2013 11:24:38 PM

Rastus · UNSTOPPABLE!

Hello people,

There can be at times a lot of confusion with people about modifying cylinder-heads, and the benefits of such mods for the out-lay of dollars involved. So what's the best way do deal with these items ?...Do you recondition them yourself ? - ( you can buy all the equipment for grinding valves, fitting seats, grinding ports and installing new valve-guides etc etc) Or do you send them away for a shop to re-condition ? Or do you just buy new / reconditioned ones off-the-shelf that have been set-up ( or manufactured new ) to suit your budget or Horse-power expectations ? There's actually quite a lot more to think about even, as everyones needs will be different from one person to the next, but what still remains, is a decision about what to do with your heads ! In this next post, I'll try to put some facts up about results that have been proven on the flow-bench etc, and you might just be able to save a few bucks if you were thinking of putting something on that you don't actually need. You can do it all yourself, but probably things are best left to the pro's.

HEAD PREPARATION

Modifying cylinder-heads for high performance can be a long and tedious job, but nevertheless, one that can improve power out-put right across the rev-range of your engine. When we go looking for more power, our objective is to get the heads to "breathe" as well as possible. The more fuel and air that can be passed into the cylinders in a given time, the more resultant power will be. Unfortunately, the gas-flow characteristics of an engine are not easy to understand, and often the obvious is far from right. You would expect for instance, that the bigger the valves, the better the breathing. However, this is not always the case. In many instances, the fitting of valves which are too big does nothing but lose power. The same goes for ports, they can also be made too-big. It's always better to replace your valve guides with new ones, and new valves are always a good thing. Replace your seats as needed, though like your valves, they are made to be re-serviced where possible...

There is a definite relationship ( in the form of a ratio ) between inlet-port-area & valve-area, & for a typical 2-valve per chamber cylinder-head, that "Ratio" is normally between 0.75 - 0.85 to 1, where 1 = the size of the valve-head / seat etc. The more efficient the valve & its seat are in passing air, the greater the port size required for the best results. For instance, a typical 45-degree seat, and rough-cast ports may dictate that the ratio of the port-size here is as low as 0.7 - 1 of the valve-area. If the efficiency in the region of the valve is vastly improved by subtle reshaping of the chamber in the region around the valve-head, and by ensuring a slightly contoured venturi plus, a mandatory 3-angle valve & seat cut, then the optimum port-size ratio can go up from the previous 0.7, to near 0.85 -1 of the valve area. Everything is "proportional" and we can only do so much with what we've got ! But a 15% improvement (on average) on air-flow just by "cleaning-up" the port & providing a 3-angle valve-job is something to open your eyes too ! Enhancing the port-area in effect means that we make the greatest use of the "momentum" of the incomming gases. If its too-small, it becomes a restriction, & if it's too large, the gas-speed is slower, thus losing any advantage to be gained by the use of its momentum. We have to remember here that once an engine is running, - even at idle, there is a "momentum" of air movement flowing into all of your cylinders, that grows as rpm increases...Your vacuum gauge indicates this... The most important part governing the breathing ability of a cylinder-head is is the area approx. 1/2" before the valve-seat, & about 1/2" after the valve-seat...It must be your objective to make it as efficient as possible within the inherant limitations of what your stuck with. Follow OEM specs with regards to the width of the valve-to-seat contact area, but 1mm is a not-un-common optimum width, with the valve normally having a 45 degree cut & the seat having a 46 degree cut.

A different set of conditions present themselves on the exhaust side. We would hope to find that the port-area on the exhaust side is larger than the valve area. Usually port areas are in the range of 0.9-1.05 of the valve area. The valve seat requirements are not nearly so critical, as the seat ( & guide ) are needed to transfer the heat away to the cooling water, so once again, OEM specs are the best to follow here. At least make sure that the width of the contact area of the valve-to-seat is 1/16" wide. ( Don't forget that it's easier for an engine to exhaust waste gasses under pressure than it is to fill with a fresh intake charge ). Any work in this area should be limited to removing any casting-dags &/ or sharp edges, though polishing can prolong the time it takes for carbon deposits to start building up again.

PORT SHAPE

There's not a lot that should be done here ( without going radical or on some experiment ), as we're pretty much stuck with what we've got. Look for consistancy of a smooth surface, gently grind / buff away any casting residuals, but do not alter the port size ! This should be done by the Pro's at the Machine shop, and usually it's done to correct intake manifold alignment and maybe to optimize gasket fit etc etc etc. However, it might be worth knowing that a round port flows around 10% better than an oval one, and up to 15% or more better than a rectangular one. Should you be lucky enough to be running a Mercedes engine, you will note that all their engines have round ports !

COMBUSTION CHAMBERS

It's not advised to go modifying anything here, except to say that you need to remove all sharp edges, points & dags to prevent the possibility of hot-spots & detonation, & that all your chambers need to be equal in volume...Better to let the specialists tackle this ! Any other mods are usually associated with the removal of metal from the chamber when over-sized valves have been fitted ( if found necessary to have ) so as to reduce the negative attributes of what's called valve-shrouding. Valve shrouding is where the positves of fitting over-sized valves are turned negative by the valve being too close to the combustion chamber wall when opened, thereby reducing the flow of intake charge, and taking away any hopes of power improvement. Once again, leave it to the pro's.

Cheers,

Rastus

SELLC · CERTIFIED POST WHORE

stoma wrote:
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THOSE VIDEOS SHOW JACK SHIT.................... CAN'T SEE TIMES AND EVEN BETTER................ CAN'T TELL WHO WON!!!!!!!!!!!!!!!! WHAT A FUCKIN LOSER!!!!!!!!!!!!!! AHHAHAHAHAHHHAHAHAHAHA!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! NICE TRY FAGGOT!!!!!!!!!!!!!!!!!!

LOL

I didn't even see this post ^^^^

Rastus · UNSTOPPABLE!

Hello people,

Let's move on to the next part of our engine assembly checking...

FREE RUNNING CHECK

Once the assembly of pistons, rods & crank into the block is completed, a "free running test" should be carried out. This is best accomplished with the front crank-bolt fitted and checking the torque needed to turn the engine over with a torque-wrench. The average torque required to turn the bottom-end-assy over should definitely not exceed 8 lb/ft per litre of engine capacity. If you've been on-the-ball & done the job very carefully, the whole assembly should turn when 4 lb/ft per litre is applied...

eg, a 560 MB V-8 displaces 5.6 litres, so let's calculate the maximun turning torque required of our bottom-end assy...

5.6 x 4 lb/ft = 22.4 lb/ft...This figure would be a very good result, & guarantees that we've done a spot-on job of assemly. ( * approx 61 cubes is = 1.0 litre )

What do you do if the turning torque for the engine is too high ? ie, in excess of 10 lb/ft per litre ? Very simple...Strip everything back down & start checking it all out again until you've determined exactly what's at fault ! This may seem a little "over-kill" but there's much more to enhancing your engine than fitting a performance cam(s), tuned exhaust, modified cyl-heads etc etc...

Suppose we have an engine of 7.0 ltrs capacity, & it has an internal friction level of 10 lb/ft per litre, which isn't an unreasonable figure for an engine in "as-new" state from the factory. The power absorbed by the friction of the crank, rods & pistons on such an engine running at 7,000 rpm would be 93.8 B.H.P. Now compare this with an otherwise identical engine which requires only 4 lb/ft per litre to rotate the crank assy...This second engine would only absorb 34.72 B.H.P.. This means that we would have nearly 60 B.H.P. extra at the fly-wheel to perform useful work on propelling the vehicle that would otherwise be lost as friction within the engine.

By using lots of patience & being very thorough, it's very likely that you can turn even your otherwise stock-engine into a very surprising performer. I would think that with the numbers posted above, & with a little thought, you can relatively easily calculate your expected targets with the engine that you actually have.

Cheers,

Rastus

Rastus · UNSTOPPABLE!

Hello people,

I'll continue on with the "juice" to help keep everyone well-watered ! - LOL ...

CON-RODS

So now at this stage, we should go about checking the crank & rods for flaws & cracks...This is a job that can be tackled by your reputable Machine-Shop, & is not as expensive as you may think. If you do not have highly-stressed-parts flaw detected, & it turns out that a flaw does exist in one or more of the components, then the resultant mishap is usually "very"expensive to remedy. You could think of this flaw-detection as nearly like taking out an insurance policy.

We have to check our con-rods for truth...Bent or twisted con-rods can also be a great source of power-loss, so no gross inaccuracies can be tolerated. Firstly, the centreline of the little-end & big-end must be parallel. Any error when checked over the length of the gudgeon-pin should not be greater than 0.001". We need to be just as fussy about the amount of twist in a con-rod, even though any adverse effects are less marked than those caused by bent rods. Even so, the Maximum allowable twist should be kept below 0.0015"-0.002". Just in-case you're worrying as to how to check your rods, don't...Most motor machine shops can accurately check, & straighten your rods quite easily & inexpensively ! Should the rods be found to be badly bent or twisted, then they need to be replaced. You can assume that any rod that's out by 0.010" falls into the badly bent or twisted category. Make sure that the little-end bushes are not worn out. If they are & need replacing, this should be done before checking the alignment of the rods. The clearance for little-ends is usually around the 0.0005" mark. so if you go for this figure, you won't be far out.

CRANKSHAFT & FITTING

We're now left with the crankshaft to come under close inspection as far as the bottom-end assembly goes. Using an accurate micrometer, check the the sizes of the big-end & main bearing journals. If these prove to be worn by more than say 0.007", then a crank re-grind is called for. Whether the crank has been reground or not, new bearing shells are mandatory. Often the sizes of the bearings are stamped on the outside of the shell, so this will aid you in determining the correct size, or new required sizes if needed, should the crank be found to need grinding. ( Crankshafts are usually ground down to the next corresponding under-size bearing shell size ). A good clearance figure for the main bearing assy would be 0.002". Any more is too much and "sustained high rpm operation" could see bearing failure. However, as always, use OEM figures for accuracy of clearances, and the use of "Plastigauge" for measuring makes life that much easier.

Once you have everything sorted out, it will be time to start checking that everything is in order...Fit the main bearing-shells into the block & lightly oil the bearing face of each one. Place the crank in position, then fit & torque down No 1 main journal cap, together with its bearing. At this point, check that the crank spins freely. If does, then everything is fine. If it doesn't spin freely, then a tight bearing is indicated. Sometimes swapping bearing shells will cure any bearing tightness, but if this is not the case, then either the bearing shells, bearing housing-( block ) or crankshaft journals are incorrectly sized. In the case of miss-sized bearings or journals, the fix is easy. On the other hand, if its the block that's at fault, then this would have most likely existed since new, & the only remedy is to have the block in-line-bored.

Assuming that the crank spun freely when No 1 cap & bearings were fitted & torqued down, No 2 cap & bearing should now be fitted & torqued. Again we need to determine that the crank rotates freely, repeating this same procedure with each of the main-caps until they are all fitted. If the crank rotation gradually gets stiffer with each subsequent cap fitted, a distorted block or crank is indicated...The easiest way to determine whether or not this is the case, is to fit one cap at a time to see if the crank spins without undue resistance. If we find that each journal is free on its own, yet the crank is stiff when all the mains are torqued down, then definately something is wrong. Go back & check it all again until you find & fix the fault. Then start again...

Some of you may be wondering what should be regarded as "tight or loose" as far as crank rotation is concerned...You should be able to rotate a crank, even on the largest of engines, when a torque not exceeding 1 ft/lb is applied. Since most torque wrenches don't read down that low, another method can be used...The crank should spin freely with just you using 1-finger and a small amount of force...In fact it should almost run-away from you once it has started to spin...Alternatively, you could use your crankshaft pulley, a piece of rope, & a weight. The mass of the weight required to give us the required torque depends on the diameter of the pulley. Torque is a measure of turning force & is obtained by multiplying the applied force by the radius at which the applied force is turning about. eg, an 8" diameter pulley with a 1 lb weight attached to a piece of string that's then wound around the pulley will exert a torque of 1/3 lb/ft . ie.,4" (radius) x 1 lb = 4 lbs in = 1/3 lb. ft. From this example you can see that to exert 1 lb/ft torque, we need to attach a 3lb weight to the string.

Assuming that we're now at the point where the crank is is a satisfactory running-fit in the block, we need to carry out a similar check on the con-rod big-end journal fit. A good clearance to aim for is once again 0.002". When such a clearance exists, the rod will fall unaided by anything other than gravity from the near-vertical position to horizontal. We should now be in a good position to assemble the rods & pistons together ( probably best done for you at the machine-shop ) & then start re-assembling our "short-motor". Always remember to lube your pistons, bores and rings before assembly. Don't use too much oil on the piston rings as you may cause a hydraulic lock when trying to install them with the ring-compressor. They should slide in reasonably easily. Any resistance does indicate the possibility of too much oil or the ring compressor is not square to the block etc. If you keep tapping away in this situation, you could easily brake your new rings or crack pistons. Take your time and use plenty of patience...CRC make White Lithium Grease in a spray can that will all but eleminate this issue, and provide heaps of lubrication. (In fact, you can spray this stuff on all your internal components knowing that it will stick & stay there & not drain away into your sump ! - ( Especially if start-up day is still a while away !)

With all the bearings lubricated with light engine oil,re-torque down the main bearings & check the big-end bearings etc etc. It's a wise move also to use new big-end nuts & bolts where possible. We're now up to the Free Running Check, but we'll discuss that in the next post.

Cheers,

Rastus

-- Edited by Rastus on Tuesday 28th of May 2013 06:12:09 AM

-- Edited by Rastus on Tuesday 28th of May 2013 10:41:11 AM

SELLC · CERTIFIED POST WHORE

Juicy...

smile

Rastus · UNSTOPPABLE!

Hello folks,

Here's the next installment for your considerations ! Remember that these next few posts are good-"guides" only, in the sence that you're not sure about how to go about things or what you're even looking for...

HONING

Having measured the piston & established it's basic size, this figure must be added to the clearance figure to arrive at the finished bore size. Once you know what size the bores should be, you can go ahead & have the block machined - ( bored or honed as required. All bores need to be honed after boring to a new size ). The honing part of the bore preparation is essential. A plain bored finish in any engine will cost you power and durability / reliability. Should the OEM specs remain unknown, have the block honed to a 15 micro-inch finish with a cross-hatch pattern of 45 degrees. This honing is very important to ensure proper function, bedding-in, & long-term dependability of your new piston rings. The consequences if not done, could also amount to the loss of 20 or more brake-horse-power, & considerably shorter piston-ring life !

There are instances when an engine need not be re-bored. Should the bores be only slightly worn, then you may find that the required bore-size as determined earlier by the formula, is such that it will "clean-up" ( via honing ) to the new size. For instance, should the formula indicate that we need a bore size 0.002" larger than standard, and the bores themselves have only worn 0.001", then honing out to the new size will be fine. Ensure that your "old-pistons" are in good-re-usable specification, especially the ring-lands. It's also very important to ensure that the Gudgeon-pins are a good fit in the piston-bosses.The normal maximum clearance will vary from engine to engine, but generally, we can say that 0.0003" ( 3-tenths of a thou.) is permissable.

RINGS

New Piston Rings should be fitted as a matter of course to each of the pistons. Follow the fitting steps as will be provided by the information-sheet that will be supplied. Note the position of each ring as required. Typically 120-degrees separation of the ring-gap from ring to ring is normal practice. A good standard ring-gap to achieve for a high-performance engine is 0.005" per inch of piston diameter. For instance, a 3.5" diameter piston should have the rings gapped at 3.5 x 0.005" = 0.017". Having gapped all the rings correctly, you can add the finishing touches by by adding a radius of say 0.005" - 0.01" to the corners of the rings gap. This will reduce the possibility of scratching / scoring the bores, as the ends of the rings are the points of highest-pressure. This will also even the tension through the ring.

Another factor to watch is the ring to piston-groove clearance. If the clearance is excessive, we get an increased amount of bore-wear & less effective sealing than desirable. The obvious effects of this show up as a reduction of power, high oil consumption and possibly even fouled spark-plugs. The last 2-points are especially relevant if the oil-control-rings are at fault.

Should the rings be too-tight in the grooves, then ring-sticking can be experienced. This can give similar results to having rings that are too-loose. The idea is that you should check the ring-to-groove clearance to determine the pistons servicability. For a compression-ring, an ideal clearance figure is between 0.002" - 0.004". This can be easily checked with the use of a feeler-gauge. 0.004" should be regarded as the upper limit for the ring-groove clearance.

In many, if not all cases, the oil-contol-ring is not-so-critical, simply because of its 3-piece design & function. The typical oil-control-ring found on most V-8, if not all high rpm / performance engines is the segmented-expander-type. With this ring assembly, little or no ring clearance will be accurately measurable since the outward pressure of the expander section holds the other 2-rings appart, & presses them against the ring-groove. This does not mean however that the oil- ring-assy should be tight in its groove. As a test, you should find that the assy moves freely in its groove. If it's too-tight, sticking will occur, hence defeating the purpose of having the ring there in the first place !

In finishing this post, always follow the OEM instructions & recommendations, but use these above guides as an insight of at least what to look-out for, & use if there's no information to follow. Also, all this measuring / adjusting /work takes a very-long time to do. However, the results of doing a job well-done are price-less !

Cheers,

Rastus

Rastus · UNSTOPPABLE!

Hello folks,

Some of you people may well be really keen to freshen-up your engines, but maybe put-off by the expenses involved, plus your not knowing about other possibilities of how to go about a "quick inspection" with a "mild-freshen-up", so as to buy some time ( years ) before you have to outlay the big-bucks for an OEM re-build...This next post will be written for both this reasoning in mind, plus a few pointers about building a "good-goer" for the daily-driver, or whatever...

PREPARATION OF THE BLOCK ASSEMBLY

The efficiency with which the high pressure gases in the cylinders are turned into usefull mechanical energy depends mainly on the pistons, con-rods and and crankshaft. To be absolutely sure that no power is being wasted, we must pay careful attention to these points. A poorly prepared bottm-end can cost anywhere from 20 - 70 HP on engines as large as as those that we will be dealing with. If we were to realize the full-power potential of any particular engine, then even the "as-new" state of the engine is not up to what is required...

BORE PREPARATION

99 times out of 100 the standard piston to bore clearance is too little as far as Max HP is concerned. A great deal of power can be lost by the extra bore-friction and oil-drag. The power lost in this quater can be severly reduced if the piston-to-bore clearance is increased...But there are limits as to how much this can be increased before we start losing power due to other factors, namely piston rings not being able to function properly due to too-much clearance...Fortunately, there are "guides" that will help you in determining what clearances can be safely used, especially when PERFORMANCE demands out-weigh ENGINE LIFE. This does NOT mean that we are discussing a piston / bore life of a few thousand miles. When we apply the up-comming mathematical formulas, we can expect a bore-life of up to 25,000 miles ( this will vary of course depending on the condition of things when you start ) under normal conditions. It should also be pointed out that for a TRUE RACE ENGINE, the pistons, rings and bores a well-below-par after roughly 10,000 miles...And for a really high revving unit, this figure can be much lower.
As a first step in determining our allowable clearances, we must work out the Diameter to Length Ratio of the piston(s) being used. ie, piston length / piston diameter. Having done this, compare your result with the following table...

Length / Diameter ratio                           Clearance-per-inch

0.9/1 - 1/1                                               1.4 thou.
1.1/1 - 1.3/1                                            1.5 thou.
1.3/1 - 1.5/1                                            1.6 thou.
1.5/1 & over                                            1.7 thou.

From the above, we can establish the "clearance-per-inch" of piston diameter. When we multiply the "clearance-per-inch" by the piston diameter, we will arrive at the figure to use. To make things clear, let's use an example...Let's say we have a piston of 4.2"diameter, with a length of 4.8". The diameter to length ratio will be :

piston length/piston diameter = 4.8/4.2 = 1.143

Looking back to the table above, we find that this is mid-way between 1.1/1 & 1.3/1, so indicating that we should use a clearance of 1.5 thou. per inch of piston diameter. To arrive at the final clearance figure, we now multiply the piston diameter by the "clearance-per-inch"...So,

4.2 x 1.5 thou. = 6.3

There are always "reservations" when using formulas like this one posted - ( I mean, who the heck am I, and why should you believe me ?), however, when applied to when you have to determine if you can use your old/used road-pistons ( ring-grooves etc have checked & OK'd ) all will be fine !

Should you be using new OEM or racing / aftermarket pistons, always follow the rcommended clearances as specified by the manufacturer !

In finishing todays post, it might be worth-while to note how to go about measuring your pistons. If you have "flat-top" pistons, then the length measured will be the over-all length. Should the pistons have a raised crown, then the length is to me measured from the top-edge or deck-face of the piston, & not from the crown. When establishing the diameter of the piston, certain things must also be taken into account. Nearly all pistons are oval-ground and a great many are tapered. To establish the basic size of the piston, you must measure it at 90-degrees from the gudgeon-pin, and should it be tapered ( more than likely ), it needs to be measured at the top, middle & bottom of the thrust-face...The thrust-face starts just beneath the ring-belt.

Cheers,

Rastus

-- Edited by Rastus on Saturday 25th of May 2013 11:46:13 PM

Rastus · UNSTOPPABLE!

Thanks SELLC,

I'm still laughing to myself ! Your points were very valid though, & needed to be said to make life easier for everyone ! I was going to post up some photos of my little 350 motor, but wasn't sure how to attach them with this thread...I remember somewhere else on this sight that you asked for some pics from another user, but didn't get them. How do I attach some pics ?

Cheers,

Rastus

SELLC · CERTIFIED POST WHORE

Rastus wrote:
I guess I missed the point on one or two things ( plus typos ), so I'm glad you cleared a few things up for everyone.
Cheers,

Rastus

I was just giving you shit... It was a long post, but I had to find something to bitch about so you knew I read it all.

Rastus · UNSTOPPABLE!

Thanks SELLC,

I'm glad you liked the post, though I've got to admit, it was a l o n g one, with too much typing ! I tried to keep things to the point, but with so many bits of info here & there that I was drawing from, I guess I missed the point on one or two things ( plus typos ), so I'm glad you cleared a few things up for everyone. Thanks heaps, and I'll be trying to sort-out a proper layout for the Bosch Fuel Injection systems that we all use everyday, but it's not easy, & will take a little time. I really liked your rocker-removal thread, keep it going !

Cheers,

Rastus

SELLC · CERTIFIED POST WHORE

Rastus wrote:
The rods themselves are steel-forgings, carefully proportioned to to avoid stress-raisers, with balancing-pads at both ends. The cap dowell-bolts have knurled heads which are an interferance fit in circular recesses in the shoulders of the rods. This avoids the stress-raising notch that is usually milled across the skoulder to go with a "D" head-bolt.

Interesting read! But don't you think some people *cough* BW members *cough* would be confused with the statement above? Most people would think you are talking about a "Cylinder" head-bolt, when really what you are saying is the "D" shaped head of the connecting rod "Stud" (and after all isnt that what it would be called considering that it does not spin and stays fixed?). And arent these "D" studs pressed in?

But outside of that... Not a bad read... Athough I must mention that now days the old "D" studs are old school tech. Now days they use Dowel pins to center the cap with traditional hardened "Bolts" to hold the con-rod caps to the rods.

Rastus · UNSTOPPABLE!

Hello Folks

In the interests of hopefully enhancing this already cool web-sites credo, especially with regards to our V-8 powered Mercedes', I figured that it was warranted, even expected, to find out about the how's and why's of Mercedes deciding to make a V-8 engine for their passenger cars, ( the M100 V-8 of 6.3ltrs was already in production exclusively for their limousine range only ). I've found bits and pieces of information that are period specific and should inform us all about the many number of considerations that had taken place, to design and develop our sublime M116 & M117 V-8's.

A number of factors influenced the choice of vee-8 configuration when design was started in 1963. A primary requirement was to provide a larger capacity power-plant for the important USA market. Also, although West German & European fiscal laws penalized heavily any size engine greater than 2.7ltrs, imported cars such as the 3.4 & 3.8ltr Jaguars were selling well to enthusiasts. Late in the development phase of the M116 it became known that German motor tax laws were likely to be changed to allow for larger capacity engines. A 3.5ltr capacity was a sure bet for the home market, without having to pay the much inflated road tax for owning it.

Having gotten around deciding the engine displacement, a V-8 design was chosen as it was felt that a 3.5ltr 6-cyl engine, with modern over-square cylinder dimensions would prove unexceptably too-long. Also the company was very much becomming even more safety conscious & realized the need to build in a crush-area ahead of the the engine which was either empty or full of "soft" components. A long engine also requires a long bonnet !

A "vee"-engine was the obvious choice. Its shape is much easier to fit in-between front suspensions than a flat-engine, & does not compromise steering-lock. Also, there is room between the cylinders and under them for exhaust system and ancillaries. 6-cylinder & "flat-crank" V-8's were studied on paper & on computer, but were discarded. The former because of its whirl-shake, & the latter because of its own variety of 2ndry cross-shake. A main consideration was that the engine should run for 50,000miles without major attention. Sections of the USA clean-air require an engine to maintain its emission characteristics for this milage. At the same time, the unit had to be economical to produce, ( for Mercedes sell for half the price in Germany when compared to elsewhere ), had to develop 200hp, & should be capable of running at full-power indefinitely.

Constant high-speed running called for low-mean-piston-speeds to minimise wear. The 65.8mm(2.59") stroke chosen resulted in a mean-maximum-piston-speed of 2,800 feet-per-minute, which was well within the capabilities of the then modern piston ring materials. For a point of comparison, a Mercedes 2.5ltr 6-cylinder engine will operate at a mean-piston-speed of 3,100 feet-per-minute, at near maximum RPM, with a road-speed of 105 mph. The 3.5ltr V-8 is geared for 126.2 mph at near maximum engine-RPM, but with the lower mean piston speed.

If cast-iron seemed like an old-fashioned material for the cylinder-block, it should be remembered that the engine was designed at a time when "maximum disillusionment" with light-alloy engines was apparent in the USA ,- ( possibly due to failures experienced at the time by Buick, Oldsmobile & other would-be manufacturers of aluminium V-8's ), where the Mercedes V-8 was also intended to be sold. Mecedes also had a number of good reasons for the choice. Cast-iron is economical to buy and manufacture, predictable and has good-wearing & sound-dampening properties. The weight penalty was 30kg when compared with aluminium, however it was thought that at least the same amount of sound-dampening material would have been required to reduce the increased noise transmission from a light-alloy block. West German noise regulations at the time required noise-measurement from the side of the car aswell as ather places, hence it was uneconomical to introduce extra sound-dampening for this purpose alone.

Regarding rigidity, cast-iron is also better in this respect than aluminium. The short-stroke also made for a compact & therefore stiff cylinder-block & crankcase unit. Every effort was made to keep size down, & therefore weight. The result was a casting that measuered only 10.5" high, & 16" wide in its machined state. These dimensions also include the crankcase wall which extends 2.6" below the crank-shaft centre-line, almost to the bottom of the crank-swing. This was to increase the beam-stiffness of the unit when a gear-box was attached. To further increase stiffness, the 5, malleable-iron main-bearing caps are eached retained by 4-bolts in-line ( *6-bolts with the later aluminium-engines ). They do a double-duty as fasteners of the bearing caps, & as ties between the crankcase walls. The caps fit into "mortise recesses" in the crankcase partition for accurate side location. The recesses also supplement the 4-fixing bolts in preventing cap-shuffle when under high-loads.

Ample water-jackets are provided right around the bores & the full depth of the cylinders. This was essential so as to get as much rejected heat as possible away from the engine when working at full-power inside a hot engine-bay, during a very hot day.

Five 64mm main-bearings support the forged & nitrided two-plane, four-throw crankshaft. With the 90-degree cylinder angle, this arrangement is free from primary & 2ndry out-of-balance forces, and provides equal firing intervals. Irrespactive of firing-order though, the exhaust pulses on each bank are irregular, & a cross-over pipe in the exhaust system was incorporated to reduce the familiar V-8 throb, & enhance exhaust flow at lower RPM's, by trying to equalize exhaust pulses through the system sequentially from each bank of cylinders. Large balance weights on the crankshaft formed on the end-webs, are drilled for final balance. Thrust is taken at the centre main-bearing, and the high-speed garter-spring lip-seal, working on the flywheel boss, retains the lube-oil at the fly-wheel end. A very-nice point is that the boss is ground with a spiral-pattern to work as a micro-groove "Archimedian" pump, that will push any stray oil back into the sump. Also, very much worth noting, is that so the main-bearing-cap-recesses and faces can be machined in 1-pass of a milling-cutter, the rear main seal is carried in a bolt-on diaphragm assy.

These compact dimensions of the engine were not achieved at the expense of an un-favourable "con-rod to stoke" ratio. On the contrary, the 135mm rods ( between centres ) provides a ratio of better than 2 to 1. Apart from reducing piston side-thrust, there is room to use a larger stroke crankshaft in conjunction with a taller cylinder-block, using the same con-rods...( This would lead to the birth of the M117 engine family ! ). The rods themselves are steel-forgings, carefully proportioned to to avoid stress-raisers, with balancing-pads at both ends. The cap dowell-bolts have knurled heads which are an interferance fit in circular recesses in the shoulders of the rods. This avoids the stress-raising notch that is usually milled across the skoulder to go with a "D" head-bolt.

Big & small-end sizes ( of the con-rod ) were 52mm & 26mm respectively. Lubrication to the fully-floating gudgeon-pins is via a drilling through the con-rods, & from oil-traps in the faces of the pistons. The Pistons are 92mm in diameter, hypereutectic, light alloy-forgings with cast-in steel anti-expansion rings. Knowing that customers were likely to drive the car flat-out from the word go, all the rings had molybdenum-sulphide inserts. 2 compression & 1 oil-scraper-ring ( 3-piece ) were fitted. The 2nd compression ring was interesting in having a recessed nose ground in the lower face, & a backing spring...

Going against the trend towards bowl-in-head pistons, the M116 was given cross-flow wedge-heads, with large squish-areas. Mercedes found that large quench areas remained hotter than smaller ones, thus reducing hydrocarbon emission out-put. The size of the vestigial combustion-chamber was virtually defined by the size of the 44mm intake valves which are inclined at a 20-degree angle from the verticle position, and work on hardened cast-iron inserts in the light-alloy cylinder-head. Inlet-throat diameter is 40mm with 38mm inlet tracts. This diameter would provide a mean air-speed of 280-feet-per-second at full-speed, which is relatively slow, & is the probable reason for the high-speed 4000 RPM at which Max. Torque is produced. However, carefull camshaft design and analysis provided a relatively flat, yet productive & strong Torque-curve, giving as much as 170ft/lb at 100RPM, and a Max. of 211 ft/lb at 4.000 RPM. ( 286Nm @ 4,000 RPM for those of us who are metricized...). Camshafts had an installed "Scleroscope Hardness" of 70-82 when new, with a wear limit ( or critical limit ) being 62. Exhaust-valves were Sodium-cooled with special attention being paid to water-cooling / flow around the valve-guides.

Mercedes preferred the valves of their over-head cam engines to be rocker operated. The trend to go shim-under-bucket would have meant costly & specialized service requirements when the service adjustment was required. The 50,000 mile minimum maintenance interval ( for emission output ) would have probably not been possible as required by the then USA clean-Air regulations. Using adjustable rockers meant that most work-shops could perform the task successfully throughout the world without the need of specialized tools / equipment. The Rocker layout has the rockers pivoting on spherical-headed adjustable posts, with the valve actuating end securely located via slotted buckets resting on top of the valve. Adjustment was carried out with the use of a feeler gauge in-between the rocker and camshaft base-circle. This layout ensured that line-contact with the cam is maintained & left the opportunity to simply convert to "Hydraulic compensating elements" at a later stage. This move would eliminate the need to adjust valve clearances due to the automatic hydraulic compensation. Each rocker weighs 80 grams, of which 28 grams is reciprocating weight.

Mercedes chose to use a single Duplex ( double-row ) timing chain rather than a belt to drive the camshafts and distributer drive gear, mainly because of the known long life of a chain. The single run duplex chain is driven by an 18-tooth sprocket on the crankshaft, & passes around 36-tooth sprockets on the camshafts, & under a 36-tooth distributor-drive-sprocket located in the vee at the front of the engine. Long rubber-coated ( back then ) steel-spring guides check lash on the drive-side of the chain, & a hydraulically-backed spring-tensioner controls / maintains the slack-side. This whole assembly is contained by a simple, die-cast alloy cover in which are formed the water-pump & distributor-drive housings.

Lubrication is provided by a gear-pump slung beneath the front main-bearing-cap & driven by a chain-reduction-gear from the front of the crankshaft. Mercedes preferred chain-drive for this application due to the high-loadings produced when using scew-gears. They only tolerated them for the distributer-drive because of its light-load. Oil is picked up from the wall of the stepped sump by a collector fitted with a specially shaped diaphragm-pick-up. It will maintain suction even when the oil is surging under 1-G cornering forces. The shallow sump design was dictated by the need to keep engine height to a minimum, that would allow the engines fitting into many-number of potentially new body / chassis designs, then, and into the future. This fact also allowed their stylists to work with a low-bonnet-line, aiding in new body design asthetics / styles.

Oil, once picked-up, is pumped to a cooler (via a damper), before being filtered & passed to the crankshaft. Separate drillings from the main-gallery, located in the angle of the vee, are taken to copper-pipes running the length of the cam-boxes, whilst feeding the camshaft bearings. The camshaft-lobes are then fed via an oil-tube secured in place to the cam-bearing-towers by clip-in plastic retainers. The camshaft-drive-chain is lubricated by oil-mist.

Cooling was straight-forward with the use of an involute-pump that was bolted to the front timing-cover. It was driven, along with the steering-pump assy via 2-drive-belts from a multi-groove pulley on the crankshaft. The viscous-fan, with a thermal-clutch, was mounted to the outer-end of the water-pump-pulley. Water was pumped first through the cylinder water-jackets, then reversed through the cylinder-heads (& intake-manifold) and on to the radiator via a temperature regulating (wax-bellowed) thermostat-valve, located in the water-pump housing. Suction was obtained from the lower-radiator hose inlet, with quick-engine-warm-up times achieved via a by-pass water-re-circulation system,when the thermostat valve was in the cosed position. This restricted water flow of the cooled / cold radiator water.

Having Bosch practically only around the corner, it was only natural for Mercedes to go to them for their electrical and petrol-injection equipment & services. The Bosch Transistorized Ignition & Electronic Fuel Injection ( "D" Jetronic ) was triggered by 2 independent sets of trigger-points located within a Bosch Distributor. - ( 1-set was used for the dwell-time of the low-current flowing in the primary-side of the ignition-coil, - ( to provide the spark-plugs with the required current to generate sparks in the old "traditional" way), & the other "bi-set " to provide a signal to the computer to initiate the fuel injection pulse-sequence...).

Induction air is drawn through a "pan-cake" style air-cleaner assy into a hollw cast-alloy vertical trunk, where the throttle-valve / butterfly is located. This inturn feeds a horizontal manifold / plenum-chamber located in the vee of the engine, from where 4 - "swan-neck" pipes each feed a pair of inlet ports. Fuel is injected through vertically mounted solenoid-controlled fuel-injectors, just upstream of the engines intake-valves. As with the earlier mechanical-fuel-injection-pumps manufactured by Bosch, ( aka M100 6.3ltr ) the injection-pulses are not exactly timed with the engines valve-timing...There are 4 - pulses to 2 - turns of the crankshaft, & each pulse injects fuel into 2 - intake tracts, that are paired or "grouped" in the order 1 & 5, 4 & 8, 6 & 3, 7 & 2. - ( this is obviousely phased the same as the ignition-system firing-sequence, though naturally timed at different crank-shaft positions ). For example, "group - 1" injection takes place for 2 - cylinders, ( 1 & 5 ) after the intake valve of No.1 cylinder has been open for 30-degrees of crankshaft rotation, with fuel being injected simultaniousely in No.5's intake-port, even though the valve is due to open after another 60-degrees of crankshaft rotation. The Injection-Systems Computer will take into account throttle-position, intake-manifold-pressure & barometric pressure, cooling water temperature and air temperature to help it determine the correct "open-time" of the fuel-injectors solenoid-valve. The temperature sensor ( since it's constantly variable ) is also utilized to activate and control the operation of what's now known as the auxillary air-valve, which provides an air-bleed in the manifold to maintain good idle-speed at the lower engine temperatures.

The virtue of this injection system is that it provdes the same job that can be had of an ideal 8-carburetor induction set-up...eg., one carburetor feeding one cylinder. Power and especially Torque outputs are very-much enhaced ( Torque potential is up to 30% better when compared to an American single- 4-barrell carburetor design feeding all 8-cylinders ) whilst emission outputs are significantly reduced.

I've tried my best to provide as much usefull information with regards to the little 3.5ltr V-8, (as it was the genesis engine of the M116 & M117 engine families), with the intention of informing everyone of how their Mercedes V-8's, (regardless of the capacity ), all started from this tiny motors humble & complicated beginnings ! This little motor ended up producing 200hp ( 147kw ) @ 5,800 RPM with a red-line at 6,300 RPM, and as already mentioned, 211ft/lb's ( 286Nm ) of Torque @ 4,000 RPM, with the capability to propell a vehicle to a top-speed of 126.2 Mph ( or if you rather about 205km/hr ). I reckon that's not too bad an effort for the mid-1960's & with a further 25 years of the engine families production life-span, & countless millions of miles now traveled by happy owners world-wide, It's gotta be worth writing about ! Long live the Benz V-8's !!!

Cheers,

Rastus

Rastus · UNSTOPPABLE!

Yo folks,

As a point of further interest...Whilst visiting my folks a little while ago, my dad brought out another one of his rare Mercedes Books, with this ones subject being the C111 prototype cars built between 1069 and 1979. Ultimately I found it fascinating to read through, and how the on-going development of this vehicle has filtered in a lot of ways to the new cars we can by today from Mercedes.
Anyhow, there were 4 different marks of this prototype vehicle that started with a 3-rotor Wankel Rotary engine, then a 4-rotor Wankel engine, followed by turbo-charged Diesel engines, with the final version being a twin-turbocharged M117 V-8 ( 4.5ltr bored out to 4.8ltr ) and producing well over the 500 hp mark...Aero-dynamics and other fascets were all incorporated into this prototype for analysis etc, and you wouldn't believe me if I told you about the fuel economy figures they were getting with the diesels, so better you investigate the C111 for yourselves. The use of plastics etc were also being considered for future applications, but the main goal as it would appear were to beat speed records etc. I'll try to "borrow" the book and post some facts up if anyone wants some "official figures", but I thought I'd see if you folks were interested first.

Cheers,

Rastus

Rastus · UNSTOPPABLE!

Hello gerryvz,

Thanks heaps for the chance to read the article ! I reckon you'd be still laughing at what was said about sliding at high speed around the circuit....In your car !!! It must be a highlight in your life to have had your car driven around a race-track, by the man who ultimately made it !!! - Very lucky indeed !!! Do you still have the car ? These 6.3's just ooze class all over the place I think, still appeal in a BIG - WAY !

It's also really good that you went all out to not only hire the race-track for the day, but to send the invitation to Mr.Waxenberger for a fun day out with the chance to drive the cars that he created, in the good company of people who very-much appreciated his efforts. I'm sure that everyone involved would have shat-themselves when the news arrived of Wax's comming over ! I'm still laughing knowing that he must have been around 70 years young going sideways around Portland International Raceway...Then being told to slow down...Only to pick the pace back up again after a few more laps !!! This was a really cool thing to post up here mate, can't thank you enough ! I have a funny feeling that a few people on this site will more than likely be doing similar things at the same age !

Cheers,

Rastus

gerryvz · Member

Hey Rastaman,

here's a good article for you to read. It's from issue #1 of the brand new English magazine called "Classic Mercedes."

Most amusing thing about the article is at the end, where Wax talks about the time I hosted him at the 2001 M-100 Group gathering in Portland, OR (the article mis-quotes it as "Parkland, Oregon) where I used to live. We rented out the entire Portland International Raceway track for an entire day (total cost was like $9,000), so we had a full day of both quarter-mile running and hot laps. All to ourselves. It was awesome.

The story that Wax describes about the track manager (a guy by the name of Mark Wigginton, who now writes for Sports Car Market magazine) being all freaked out and upset about Waxenberger's track antics (much of it in MY 6.3, I might add, with me hanging on for dear life in the passenger seat), is all 100% true. I was the person (as the overall event host) who Mark was complaining TO. And he indeed gave Wax a checkered flag at the end of the day to sign. I witnessed all of it first-hand

Enjoy the article. If it weren't for Waxenberger creating the 6.3, none of us would be enjoying our V-8 Benzes, particularly the sleeper sedans like the 500E, AMG E55 etc.....

let me know what you think. I cut my Benz teeth on the big-block M100 engine, of 6.3 liters, which was MB's first-ever V-8 and was produced from 1963-1981. It was only ever used in 3 cars.

-- Edited by gerryvz on Friday 7th of September 2012 12:06:11 AM

Rastus · UNSTOPPABLE!

Yo folks,

I was reading through all of the blurb that's been posted here ( yeah, mainly by me LOL !), and realized that SELLC has always reaffirmed or "set it straight" when needed, plus placed things into like a current-stand perspective. I know forsure that qt. " Technology, through evolution, is the mother of all horse-power...", especially now-days where often (believe it or not ), the quest for horsepower still exists, but sadly, has moved from the top priority of a car manufacturers list, so that all af todays "legislative" requirements are adheard to first off.
There are always going to be sneaky-peaks at prototype cars and what-not, but I thought it even more sad when I realized that the "hey-day" for cars ( and motorcycles ) actually happened way back in the 1920's &1930's...

I'm not sure if they'd used (or discovered) nitous back then, but man they were doing things that we still try to replicate to this day ! Probably the best way for me to explain what I'm trying to say is to get you guys to check out the specs of the Mercedes Benz W125 from 1938....A 12 cylinder, 5.5ltr Supercharged engine, producing 736HP, and capable of over 268mph...This is a car that would give the W16 Bugatti run for its money ! LOL !

Cheers,

Rastus

Rastus · UNSTOPPABLE!

Hey SELLC,

I would probably be among the first people to buy a set of "Roller Rockers" for my Benz ! What a great suggestion ! I also thought that I should briefly mention that as good as having a Roller Follower for the Camshaft would be, to gain the extra "rocker ratio" you mentioned, you would have to introduce a "Roller Tip" to where the rocker would then "roll" over the valve tip locator, to get a subtle improvement. ( It has been approximated that potentially a 6 degree increase in duration is to be expected...). This spacer / rocker locater is also the "valve-rotating" element for our engines. Also, to increase Rocker arm ratio more substancially on these motors, you would actually have to move and relocate the cam-bearing towers outboardboard, away from the vee on both banks, to get the exra leverage from the rocker that your suggesting...There's possibly other ways, but this way would maybe let you use the current rocker fitted, a no-doubt limited amount. Probably much better to re-grind the cam to how you'd like it.

I also thought that you might like to know ( if you didn't already ) that our M116 & M117 engines were originally design wise considered for "shim under bucket", direct valve actuation by the cam, but the idea was shelved due to believe it or not, American "Clean Air" regulations that stated that an engine should require minimum maintenance, and maintain correct emmission out-put for at least its first 50,000 miles. At this point in time, the Shim under bucket design was considered too much of a risk to this requirement, as if it didn't need re-adjustment at this milage, it would need it very soon afterwards. Also, it was thought that the amount of workshops nation-wide, would not be capable of performing such a specialized, and time consuming maintenance task, so we (happily) got adjustable rockers/tappets initially, followed by the maintenance free "hydraulic compensating elements" as fitted to your 560. Another thought was to go with "Timing Belt Drive" for the Camshaft, but once again, belt life back then was considered way too short, and we got "Duplex Roller Chains" instead. I can't stress enough about how gratefull I am about having a chain instead of a belt !!!

Also with regards to my last post on camshafts, it's probably worth mentioning to people that although there are heaps of cams to choose from, caution is needed before you buy, as you never know what the actual capacity was of the "test-mule" engine, or selected computer program etc etc. What I mean is that in the case of the cast-iron small-block Chevvies, they came out in more varied capacities than any other engine make I can think of, and yet the cam you buy for it, will fit all these differing engines, but behave differently in each one. Generally speaking, the larger the engine, the tighter the LCA ( or "bigger" cam) you can afford to go, and achieve the targets you aimed for. So don't ever take the Power - Ranges the cam-card says for granted, as the "same" cam will behave differently from a smaller capacity engine to a larger one, and you'll miss your power output in the RPM range you hoped for. And if you have an Automatic transmission fitted to your car and don't know the stall-speed of the Torque convertor, it would be better to keep to less than the 285-degrees duration as mentioned in my last post. It gets quite complicated doesn't it ?

Cheers,

Rastus

Rastus · UNSTOPPABLE!

Yo folks,

There is absolutely no easy way in one small post on this site to inform people out there about performance camshaft-selection and design, as every different 4-stroke engine working in the real-world has its own in-build design faults, that cam-manufacturers (and car manufacturers ) have to over-come individually, depending on the engine being considered for such a modification. Some engines utilize hydraulic camshafts with hydraulic lifters, others have overhead-cam designs, and others still ( especially now in modern times ) use double overhead camshaft designs, that are the ultimate for performance, as valve-overlap can be easily adjusted/modified to suit power-output in desired specific RPM ranges... ( More on this a little further down the page...).

Probably the best way to go about choosing a performance camshaft for your engine, is to find out what the current specifications are of the cam living in your engine at the moment, and then deciding where you would actually like to see more improvement in your engines out-put. I'm going to base this post from the point of view that you'll be thinking about replacing the camshaft by itself only, with no other mods to the valve-train or cylinder-heads, and improving engine-output for an otherwise standard vehicle only, not for an all-out race car, as this involves very major modifications to every part of the car...

Why do you need to know the specs of the cam living in your motor ???

By knowing these specs., you can then decide whether the cam your thinking of buying is actually going to improve your power out-put to where you want it or not, by comparing it's specification against what you already have.

What are the specifications and what do they mean ???

There are normally 3 specifications regarding camshafts that need to be understood, so that you can make an educated calculation as to the performance enhancement to be gained. These 3 variables all effect one another, and power output, depending on their given values, and it's very tricky to picture in your mind what's actually going on with regards to the gas-flow improvement potential. These specifications are known as Lift, Duration, and Valve- Event Timing.

* Lift = Valve lift is measured in (U.S.A.) thousandths of an inch, and is the maximum distance the valve is lifted off its seat.
* Duration = Valve open duration is the length of time, measured in crankshaft degrees/rotation, that the valve is open.
* Valve Event Timing = The positions of the crankshaft at the point where the valves are considered open, or closed.

Of these 3 major design "yard-sticks", Duration is certainly the most well known among performance enthusiasts. This is due to the straight-forward manner in which Duration affects power-output. Fundumentally we can say that, within reasonable limits, the longer the valves are held open, particularly the intake valve, the more top-end power the engine will produce. However....If valve duration is increased beyond a certain point, additional top-end power will be produced at the expense of low-end performance. In Racing applications, top-end power is virtually all that counts, but for a high performance street-machine, drivability and low-speed torque are just as important....eg. There's no "real-world gain" in being able to make 40 or 50 extra hp at 6,500 rpm, if the guy next to you gets 2-3 car lenghts on you "off-the-line" with his extra 40 ft/lb's of torque at 2,000 rpm...

Finding the optimum Valve-lift can be an asset in producing horse-power because it can add power without substancially affecting low-speed performance...In theory, the answer appears simple...eg. Design a cam with short valve-open duration to maximize low-end power, and very high lift to give top-end power...However, valve-train mechanics are never this simple, and in this scenario, the high valve acceleration rates ( from open to closed ) developed by profiles like these, substancially reduce valve train reliability by increasing loads/stresses ( not to mention vibrations and harmonics...) on springs and every other valve-train component etc., and inevidably increases valve-guide wear... Generally speaking, camshaft manufacturers "blend" a complimentary amount of duration, for the required/desired amount of valve-lift, so as to provide reasonable longevity of all valve train components when carefully matched together. This is why "cam packages" are often recommended for long term reliability and enjoyment...Also, it is GENERALLY considered that about 1/2'' valve lift for all road-going OHV V-8's to be thought of as the "rough" maximum, if long-term reliability is a major considerstion. (This is a huge variable depending on your brand of engine...but not an unreasonable yard-stick either, as you can always extend your duration and event-timing to make up for this short-fall !).

When the the intake valve is opened "early", and the exhaust valve is closed "late", ( Relatively speaking with piston at TDC beginning its intake stroke ), there is a period of time when both valves are open. This is called "valve-overlap", and its effect, called "scavenging" harnesses the moving mass of exhaust flow (as a sort of vacuum cleaner), to draw out residual burnt gasses and initiate induction flow. How long the valves are held open together, is a built in dynamic, directly related to either the duration, and/or the Lobe Centre Angle (LCA) of the camshaft design. With lift and duration remaining unchanged, it can be generally stated that, the more valve overlap present, the higher the peak power out-put of the motor will be experienced, at the expence of low-down power and torque.... The same spec. cam with LESS valve overlap, will make less peak power, but have a much wider power-band, provide better fuel consumption due to better manifold vacuum, and will be a much more managable engine to control on a driving day - to - day basis. The "valve - events" usually provided on the cam card when you buy one, will allow you to calculate just how much valve-overlap exists in your camshaft selection.

Selecting a "performance" camshaft should begin by making 2 important decisions...

1 Determine the main operating power range of the engine.

2 Determine how long the camshaft must survive...

The importance of No2 is especially relevant when choosing a solid or hydraulic flat-tappet cam, particularly for performance applications involving the ever-popular "small-block" Chevy, and several other high rpm V-8 engines. There are so many different manufacturers out there, and so many years now of development, that it would be pretty hard to make a "bad" choice. Ask people "in the know" about your engine, and what they have to say about particular camshafts, and then base your decision on some of the facts written above, as hopefully now you can understand what they'll be talking to you about. Also, as a very GENERAL guide, I've decided to post up a selection criteria with some numbers so you can have a more informed perspective on camshaft selection...

FOR STREET USAGE

* Maximum engine speeds should be kept below 6,500 rpm.
* Valve lift should not exceed approx. 0.500-inch.
* Cams with 270 - 285 degrees of intake valve duration are suitable for High Performance street / strip applications.
* Once valve-overlap exceeds approx. 40-50 degrees, all power gains are achieved at the loss of low down torque, and idle quality will begin to suffer, meaning poor
starting and running when the engine is cold.

FOR RACE APPLICATIONS

* Maximum engine speeds may exceed 9,500 rpm.
* Valve lift will be approx. 0.550-inch for track usage, and up to 0.650-inch for pure competion, Maximum HP requirements.
* Cams with 285 - 295 degrees of intake valve duration are suited for "mild" race engines, say up to 7,500 rpm.
* Cams over 295 degrees are generally best for all-out competition.

Also, optimum power in any racing effort can ONLY be obtained when intake manifold volume, header tubing size, "carburettor" air-flow ( and number of barrels ), compression ratio,combustion chamber design, port configuration, and many other variables are evaluated in a careful testing program.

My personal experience has shown that almost all the different camshaft manufacturers make a particular and VERY SIMILARLY SPEC'd camshaft that's suitable for supercharged and/or turbocharged vehicles. They're typically a "split-duration", dual-pattern cam having "around" 295 - 300 degrees duration, "around" 0.500-inch lift, and around 70-75-degrees overlap... But at 0.050-inch valve lift, ( this is the measured lift required of hydraulic grinds where the measurable flow of gasses actually starts to happen ), the intake valve will then have a calculated 224 degrees duration, and the exhaust valve will have 234 degrees duration. (Hence the term "split duration"). These cams work more than fine in naturally aspirated engines, and I would "advise"(?) anyone in doubt about what to use, to fit one of these spec'd babies, as the more than satisfactory results that I have recieved from fitting the said cam to my 5.0 ltr V-8 were, and still are very, very, impressive. Incredible throttle response... Awesome agressive mid-range acceleration with a singing top-end...And with minimal loss of low-down torque and power...

In finishing....The fitting of ROLLER ROCKERS is probably the first place to start improving the performance of any OHV V-8 that uses push-rods, as the benefits of these items probably need me to write another page of blurb, and I'm not goin to do that today ! I do hope that if you've taken the time to read through all of this info, that you've gained a little more insight and confidence in dealing with the huge world of camshafts. Regarding our beloved Mercedes Benz engines, what can I say, I know mine already revs to 6,500 rpm, so I'd say it's already been sorted out by the factory!

Cheers,

Rastus

SELLC · CERTIFIED POST WHORE

Rastus wrote:
Yo folks,

There is absolutely no easy way in one small post on this site to inform people out there about performance camshaft-selection and design, as every different 4-stroke engine working in the real-world has its own in-build design faults, that cam-manufacturers (and car manufacturers ) have to over-come individually, depending on the engine being considered for such a modification. Some engines utilize hydraulic camshafts with hydraulic lifters, others have overhead-cam designs, and others still ( especially now in modern times ) use double overhead camshaft designs, that are the ultimate for performance, as valve-overlap can be easily adjusted/modified to suit power-output in desired specific RPM ranges... ( More on this a little further down the page...).
Yeah, it's called Electronic Variable Valve Timing although every manufacturer has come up with their own unique way of saying the same thing. It's proof that technology, through evolution, is the mother of all horsepower. I'm green head to toe when it comes to going faster for less. LOL!

In finishing....The fitting of ROLLER ROCKERS is probably the first place to start improving the performance of any OHV V-8 that uses push-rods, as the benefits of these items probably need me to write another page of blurb, and I'm not goin to do that today ! I do hope that if you've taken the time to read through all of this info, that you've gained a little more insight and confidence in dealing with the huge world of camshafts. Regarding our beloved Mercedes Benz engines, what can I say, I know mine already revs to 6,500 rpm, so I'd say it's already been sorted out by the factory!

In the case of a Mercedes-Benz engine you would need a "Roller Follower" which I have said SEVERAL times would no doubt increase horespower and performance drastically. I am unaware of ANY roller follower for the 560 SOHC engine. No doubt anyone who produced a set with a slightly larger ratio and a roller wheel in the center to "ride" the camshaft would sell more than just a few sets. HOWEVER it may become necessary to harden the camshaft and modify the lobe for optimal performance as often times OHV (I call them under head cam engines or Pushrod engines) will have drastically different camshaft designs from a flat tappet cam and a hardened more round roller cam. Thus it's going to take more than some punk over on BW with access to a CNC to make some sort of kit up. I'd imagine the cost of such things would make buying a DOHC M117 seem relatively inexpensive.

-- Edited by SELLC on Thursday 23rd of August 2012 12:23:41 PM

stoma · Member

GET A WOMAN, BIAAAAAAAAAAAAAATCH!!!!!!!!!!!!! NOTICE NO ONE GIVES A FLYIN ASSTRALIAN FUCK WHAT YOU SAY!!!!!!!!!!!!!!!! I FELL ASLEEP TWICE READIN THROUGH YOUR LONG ASS REPLIES!!!!!!!!!!!!!!!

SUCK MY CAWK, MATEY!!!!!!!!!!!!!!!!!!!!!!!!! CHEERS OR IS IT CHEERIO???????????????? AHAHAHAHAHAHAHHAHAHAHAHAHAHAH!!!!!!!!!!!!!!!!!!!!!!!

Rastus · UNSTOPPABLE!

Yo folks,

I have to say that RSJ may give a damn, as he replied(?) once again in his no-brain, no-sense manner ! I was initially a little concerned as to RSJ's mental state of mind, as seems to know a lot about qt "saucage three-somes"..., but when it comes to buggery with animals, serious questions must be raised about a lot of things, especially the fact that he is a member on this site....Whoa, what's the world comming too ? Lucky it's not my problem....I think that maybe we all have to reconsider reducing the amount of IQ given to him to much less than several multiples of a Jap engines output ! And maybe a visit to a mental-health practitioner....Or it's possibly too late already I think...

I have to appologize to the other folks on this site, as I was warned about replying, or even acknowledging the presence of RSJ, but when someone needs help, you can't just ignore them can you ? I've also been looking around for info on camshafts for our beasts, or at least info for people to think about when they decide to go out and buy one etc., and it's quite a lot to put into perspective actually, but I think I can make things a little easier for people understand, but the biggest problem is being specific about the facts, and the facts for one engine vary from one engine make to another...However, since most people that run V-8's have the OHV pushrod type engines, there are some consistencies with these engine types as to being assured of making a "good" choice, and getting your value for your bucks for your cam selection !

I'll finish by saying that an engines camshaft is the single most governing factor determining the characteristics of the engine as a whole...You basically build everything else in the car from the design characteristic of this component... Very important stuff !

Cheers,

Rastus

stoma · Member

HEY RASTA...................... WHAT SORTA ASSTRALIAN ARE YA???????? NO ONE GIVES A FLYIN FUCK ABOUT WHAT YOU SAY CUZ U DUNNO SHIAAAAAAAAAAAAAAAAAAAAAAAT!!!!!!!!!!!! AHAHAHAHAHHAHAHAHAHAHHAHAHAHAHAHAHHAHAHA!!!!!!!!!!!!!!!! GO BOB ON A KANGAROOS DICK BIAAAAAAAAAAAAAAAATCH................................. CHEERS MATIE!!!!!!!!!!!! AHAHAHHAHAHAHAHAHAHAHHAHAHAHAHAHAHHAHAHAHAHAHAH!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Rastus · UNSTOPPABLE!

Yo Guys,

Over here in Oz we have a manufacture of oil additves etc. going by the name of Nulon. They have a product on the market (amongst many others ) going by the name of E-30. This is basically a PTFE engine oil additive very similar (if not the same ) to Slick-50. Lots of people say all these types of additives are crap and to nothing but rob you of your hard earned cash etc. I write this post confidently and very honestly to say that this particular additive works, with some amazing results...

Let me start by saying that I only bought this product because Slick-50 is very hard to find nowdays, especially down this way, but I have used it before, and at present I have and have owned a Suzuki RF-900R sportsbike since about 1996, in which case I added the Slick-50 to it way back in 1996. It's so far done 176,000 kilometers without me having to touch the engine at all, still runs fine, does not drink oil or blow any smoke, and is still capable very easily of climing to its indicated 275 km/ph...The original timing chain is still fitted, along with the original clutch...No problems of concern are yet in sight, and the bike always gets a good dose of WOT on an every-ride basis, once everything is nice and warm, after about 20 k's of riding. I also own and enjoy a 1991 GSXR-1100M, that I bought about 5-years ago, and it's going fine having added Slick-50 to it.

I was always happy with my little 350SLC, if a little disappointed with the lack of grunt from the motor due to the lack of cubes etc. The work that I do now involves going away to sea for sometimes months at a time, and so I was looking for a way to preserve and protect the internals of my little V-8. When I couldn't source any Slick-50, I had no choice but to buy/try Nulons E-30. The bottle reads that it's safe to use in motorcycles with wet clutches etc. So me being me, bought 2x500ml bottles of the stuff (@ $40:00 each ), and added it to my motor before I went away. I bought 2 bottles because the Mercs as you all know hold about 8 ltrs of oil, which is nearly double the capacity of most cars engine sumps etc.
So what about the results you may ask ? In one word, AMAZING.

The SLC is a completely different car to drive. Where in the past it would hold it's own in top gear climing steep gradient hills at highway speeds where I live, it now accelerates up them, no bull. I have also changed ALL the fluids in the car, and whilst at it, bought a syringe from the local chemist (drug-store ), and added about 50ml to the diff, 50ml to the transmission, the same to the powersteering, with the rest of the 2nd bottle going into the motor, with the "dregs" going into the fuel tank ! The car is a completely different beast to drive, and I'm honestly not dissappointed with it's performance at all anymore, as it happily pulls the car along very easily now, where as in the past, you'have to go for a lot more throttle to get it to move faster. The best way to describe this experience to you, is that it's like how your car behaves when your on holiday, and your doing a lot of miles, and after your 2nd tank of fuel, your car just wants to get up and go and roar !

I wouldn't write any of this to discredit myself or undermine anyones intelligence, but if your not using a product like this in your own vehicle, your missing out on a lot cheap and easy performance, not to mention enhance wear protection for a l o n g time. The bottle reads that it will last up to 80,000k's in your motor, even after successive oil changes etc., so I know and am completely convinced that it's a cheap and now proven friction reducing product. You won't necessarily notice it when you initially put it in, but the next time you go for a drive, I assure you all that you WILL BE AMAZED at the transformation. Almost free horsepower ! Not to mention that all the subtle"funny" running noises will nearly all dissappear.

I hope that you folks don't interperit this post as an advertisement for "another one of these products " as I'm most definetily not doing this, I'm just a very happy owner of an old SLC that's had it's performance completely transformed, and I honestly believe that your missing out BIG-TIME if you don't buy and put this stuff in anything in your car that holds oil
or has to pump oil or something around. I'll probaly buy some more and put some in with the wheel bearings when the discs need replacing. Also, these hills that I mentioned earlier, where the car used to automatically de accelerate going down them with a closed throttle ( this was only subtle de-acceleration ), I now have to apply the brakes as she speeds up now. The car doesn't actually go any faster at top speed, as it always got to it's 205 km/ph, but I would have to say that it would get there now more quickly and easier. Also, I've had to drop my idle speed by a couple of hunded revs as it climed from a steady 750 rpm in gear to about 900rpm, - enough said !

Cheers,

Rastus

Rastus · UNSTOPPABLE!

Yo folks,

I thought it might be of some benefit to further go on with exhaust system designs and concepts, as it's one thing to say "you should do this and that", and another to think about why....

1) All the exhaust gasses when allowed to escape from your cylinder via the exhaust valve and port, have several measurable qualities about them. They have volume, heat, speed, waste energy, sound, particulate quantity, and a tendancy of natural movement from a high-pressure(heat) to a low-pressure (cool atmosphere at your tail-pipe).

2) Volume of course varies depending on throttle position and RPM. The info in the last post is considered optimum for the engine sizes as listed at WOT and Max. RPM.

3) Heat is naturally given off and is Waste Energy. Due to an engines design characteristics, this cannot be harnessed in any-way if the possible Max. HP requirements are to be met at High RPM's. Turbo-chargers are the only exception to this fact, and they have their own problems that are Not part of this post.

4) Speed of the waste gasses is a quality that also varies due to a number of factors, not least of which is actual engine RPM and load. This is where the actual pipe diameters and lenghts come more-so into play...The actual purpose of Extractors is to primarily direct each "exhaust gas slug" away from the cylinder as straight and directly as possible whilst retaining some residual heat so as to not allow too much temperature differential at the exhaust valve itself, as this causes vale failure...The second feature is to provide enough length before the secondary pipes downstream, so as not to interact with and pressurise other exhaust port outlets, as this will prevent cylinder contamination. The third feature is a theoretical possibility, of where the passing of one exhaust-slug into the common "collector"-pipe ( and out the remaining pipe system to atmosphere ), creates a low-pressure in the remaining primrary pipes, thus enhancing the "extracting" of the exhaust gasses in the other cylinders that have as yet not purged their waste...This possibility is also why a "cross-over pipe" in a V-8 is recommended, as it allows all 8 cylinders to communicate with one-another, in an at least even, sequential manner, as to how the firing sequence has occurred, so as the engine sees itself as an evenly displaced/firing 8 cylinder unit, and not an uneven 2x 4 cylinder...eg, During the moments of Valve-overlap, the air just outside your air cleaner housing ( at atmospheric pressure), is in "direct communication" with the exhaust slug entering the atmosphere, at your tail-pipe exit...Pipe diameters, lengths, and straightness all affect how well these exhaust slugs are allowed to escape at their own speed. Any obstruction to reduce this exit speed leads to back-pressure, and this reduces exhaust output and power.

5) OEM engineers (and aftermarket camshaft designers/engineers), work with all these variables trying to find a Balance between waste-energy, and required power outputs at required Max RPM;s, Cruise speeds, and sitting at traffic-lights idling. This is NOT EASY and trade-offs will always exist, just due to the way a combustion engine is.

6) Sound energy ( waste energy also in another form other than heat ) is absorbed of-course by your mufflers/silencers (and all the exhaust pipe-length). Mufflers are like a cork, as even the (recommended) "Straight - through fibre-glass type" allow the exhaust slugs to Expand within themselves, and absorb bulk of the sound energy and heat, and convert it into more heat within the muffler body. It's this gas expansion and heat-transfer that reduces the sound energy, therefore lowering db's at/out your tail-pipe. Because the expanded exhaust slug now has to contract again at the muffler outlet, a reverberation effect now occurs within you muffler that's the beginning of back-pressure ( or the reverse-flowing of your engines gasses ), and gradually rises as RPM rises, meaning that your piston now has to start pushing the waste gas out the cylinder...A good exhaust will/can minimise this effect to some amount, but whilst we "Have to use muffflers of some sort", back-pressure will rise at least to some amount, and our extracting efforts will deminish as a result. Measured exhaust back-pressure readings on some factoryOEM American vehicles have been measured at over 5-Bar, whilst a good performance enhanced exhaust carefully designed, can reduce this figure to less than 1-Bar, and still be under the EPA's required 83(?)db noise limit...Some OEM exhaust pressures measure well over 5-Bar....

7) Particulate quantity is a variable typically associated with mixture quality, engine efficiency / ( condition), temperature, fuel quality and driver habbits. An exhaust system will only retain them for a little while and then expell them....- ( hopefully ).

8) The natural movement of the gasses has already been touched on earlier with regards to Valve overlap, and how the atmospheric air pressure at your air claener inlet is in DIRECT COMMUNICATION with the exhaust slug exiting your tail-pipe into the atmosphere. A free-flowing exhaust system can possibly enhance this movement of "gasses" to the point where this can have an almost "supercharging effect" occuring as the combination of extractors and exhaust take advantage of the 'momentum' present of these moving gas-slugs, thus creating an enhanced negative pressure at the exhaust port, that will ehance exhaust "scavenging", and thus cylinder filling of fresh air/fuel mixture.

There was some more stuff that I was going to go on with, but I've had enough for now, and I hope all this helps everyone in their thoughts...

Cheers,

Rastus

Rastus · UNSTOPPABLE!

Hey folks,

I guess you were right when you mentioned that RJS's IQ was lucky to be several multiples of the average Jap engines power output....He's obviousely getting saucages confused with exhaust extractor primary-pipes or something...Maybe it's something in his own diet that makes him think(?) like this, or maybe he just speaks what's on his mind...Which is a worry for sure..."He probably should have taken that left back at Albuquerque"...

I've been doing some research with regards to "Custom Exhaust Extractor Design", and should anyone be interested in how to go about providing for your engines requirements, this is the deal that you should be aiming for, as it will provide the best benefits for your cash outlay.....

1) For engines of 3.5 to 4.0 ltrs, the primary pipe needs to be 1&1/2" to 1&5/8" diameter...Lenghts will depend on the type of cam being used...A good "road cam" ( say single pattern 30/70 ) will need about 70-72" before secondry pipe join...a half race cam ( say a dual pattern 36/80, 82/33 ) will need about 76-78"... and a full race cam ( say a dual pattern 50/76, 82/49 ) will need 80- 84" before joining into the single pipe, that should be at least 18'' long and of 2&1/4, to 2&1/2" diameter before joining into a free flowing muffler...

2) For engines between 4.0 to 5.5ltrs, a similar system as far as pipe lenghts can be used, however, pipe diameter must increase...primary pipes need to be 1&11/16" to 1&13/16", with a tail-pipe diameter of 3 to 3 & 1/2" diameter...

3) For the larger engines, 5.5 to 7.0ltrs, yet another increase in pipe size is called for... Primaries should be 1&3/4 to 2.0" diameter, and the tail-pipe diameter up to 3&1/2 - 4.0" diameter...

4) Obviousely we cannot strictly follow these requirements or figures quoted due to space limitations found in our vehicles....But at least with this guide, we know what to aim for and can go for as large as possible pipes, without hopefully too much compromise...In these instances, think"Volume per lenght of pipe"...eg., if you can't fit the approx. required diameter pipe, go for a longer lenght pipe, with a smaller diameter, as the "volume" of this section of piping will calculate out the same when you get the lenght right....It's all about how well your exhaust can freely direct the waste gasses away at WOT & Max. RPM...

5) Make sure that the muffler exit pipe is at least as large (diameter ) as as the entry pipe...

6) Manufacturers compromise exhaust system designs as they have noise level requirements to address, and also by just the nature of combustion engines, they know that it's easier to empty a cylinder of waste gas under pressure than to fill it...

7) The unusual firing sequence of all V-8 engines dictates that it's almost impossible ( if not practical ) to have all the cylinder pipes joining together at an even 180 degree firing sequence as this means pipes having to join together from cylinder bank to bank. A 4 into 1 type system ( per bank of cylinders ) at least directs the waste gasses away from the other cylinders preventing back-pressure rises and cylinder dilution, though shock-wave extracting is compromised due to the uneven firing sequence within each bank...

8) The purpose of the "cross-over" pipe is to provide the communication of exhaust pulses between the banks of cylinders due to the unique firing sequences experienced with the dual-plane crankshafts utilised in most V-8's.

9) The "tri-y" exhaust extractors typically are used due to space limitations, and offer far better flow than standard manifolds or headers, and should be considered for use when the 4 into 1 system connot be fitted. Only a little power loss is experienced when compared to 4 into 1 systems.

10) The improvements to be found by going to all this trouble are quite amazing, as some people have found up to 60hp just by fitting a good exhaust system alone from a factory spec. standard engine... Improvements in fuel economy in cruise mode are also to be experienced as less throttle effort is required due to a cleaner cylinder...eg. You don't need more air and fuel to overcome residual waste gas left behind in the cylinder to to a restricted exhaust system..

That's probably all I can handle for now, & I hope this is written in an easy to digest way, and if there are any questions for where I haven't elaborated nough, don't hesitate to ask !

Cheers,

Rastus

stoma · Member

Just when I thought the two faggots gayrry and Rex were bad enough........ Rastus joins in for a sausagefest threesome!!!!! Fuckin faaaaaaaags!!!!!!!! Hahhahahahahhahahahahhahahahhahah!!!!!!!!!!!!!!!!

Rastus · UNSTOPPABLE!

Yo gerryvz,

Your a man of good resources ! I know of a guy in Melbourne (Oz) who would be happy to make something up, however he needs the time and the car etc, for an unknown amount of time etc., as it would be done in those moments when the workshops not busy, so this could mean anything from a week to 3-months ! The "Big toys" website was of some help, however they indicated a similar situation with regards to needing the car etc. This would be like you having to travel to California and waiting for things to happen ! I'll keep searching, and will find something out there I'm sure. There's no doubt somebody who can do it or maybe even has it all sitting on the shelf ! Many thanks once again guys and speak soon.

Cheers,

Rastus

gerryvz · Member

Rastafarian

I have a friend in my old hometown of Portland, Oregon who owns & daily drives 5 or 6 different 300SEL 6.3s. If I remember correctly, he had 1-2 sets of custom headers made up for a couple of his 6.3s. I could find out where he had them done. I think it was in the Portland area.

Are you Down Under? Because if so, you should really talk to Franz over at Big Toys (I think it's www.big-toys.net or something like that). The guys is in Australia and is totally mad about M-100 engines. He can do anything you want him to, and he offers some cool custom stuff too.

This page ought to keep you going for a while: http://www.big-toys.net/merc.html

Cheers !

Rastus · UNSTOPPABLE!

Yo guys,

I've been looking around on the net for somebody who makes custom exhaust extractors / headers for our V-8 Mercedes, but it seems that there's nobody who advertises their services for our cars. Do you guys know of anyone who can make up a set of tri-y's, or 4-into-1 pipes to suit my baby V-8 in my C107 ? I'm sure that your well aware of the performance enhancement potential to be realised by fitting these items along with a free flowing exhaust system, and I'm certainly keen to source and purchase the said items if they can be found. I know that there's not much room at all between the chassis and cylinder bank, steering box and pitman arm clearance,(not to mention the starter motor), but without doubt in my mind, if even a short 4 into 1 arrangement that directs the waste-gas-slug away from the other cylinders and sraight down the big-bore pipe is much better then the standard manifold, as it's basically a straight length of pipe with the cylinder branches feeding straight into it. This leads inevitably to increased backpressure and pumping losses (not to mention excess heat and cylinder dilution of contaminants as the cylinder will retain more waste gasses). Hoping that you can be compass and set me in the right direction !

Cheers,

Rastus

Rastus · UNSTOPPABLE!

Yo Guys,

I've been doing some searching about the legalities of fitting a "Dry Kit" to either of my 2 cars, and the answers are always a definitive no-go, with legal implications that would keep a lawyer struggling to keep up with the mess for at least a month ! Back in the early 1990's there were loop-holes that you could work with, but nothing anymore. Even if I could cheekily find, fit, and use a kit, there would be no-where available to provide re-fills, without doing it illegaly, and would cause hassels for more people than it should...It looks like I have to go back to mechanical type methods, to get the extra performance.

One thing I want to ask though, is what about using / substituting a 100% pure oxygen bottle to feed the motor, as surely a similar to Nitrous kit could be used, and perhaps some new loop-holes could be created ?....Sure it would be a similar set-up (the same), essentially doing the same thing, but why has no-body considered this ? You can't be producing anywhere near the pollutants as Nitrous does as your using Oxygen only. Are the fuel mixture ratios the problem as the air that we breathe only has about 23% Oxygen in it and I would be using a 100% mix ? Probably I should think these questions through myself before I post this, as I might end up looking pretty stupid, but if you don't ask, you don't know...

Cheers,

Rastus

Rastus · UNSTOPPABLE!

Yo gerryvz,

You gentlemen are really "in-tune" so to speak, as you've been there before....I dare say that you've potentially saved me a lot of time, effort, cash, and heart-ache...Not sure where to go from here except to start saving some money !!!! I thought maybe with the (yes) very old cast-iron block, and the obvious Cube increase might be what was needed from the reliability point of view with the compromise that's set at around the 500bhp mark with the ally M117. I guess when the website read ( W126 & 107's) 1979 onwards, I just thought that that's where you guys were drawing a line from, as from the benefits of your own experiences from models from that year group onwards bla bla bla...I also thought that I might have been speaking with really-young-folks, and not older pros that have been doing this for time-out-of-mind, and well beyond this humbled mechanics own experiences.

I've actually driven a number of 6.9's ( though no 6.3's, but rumour down this way has always held that the 6.3 performed better... ), and nearly bought one once, as the law was just starting to give me more than the normal road-stop liscence check hassles bla bla bla, but I found that my little 5.0ltre V-8 Commodore had better outright performance, so I didn't buy the 6.9, as it would have been a move backwards as far as performance goes, though not by too much.- ( the 6.9 has faster top speed, but the Commodore is much quicker). In case you didn't know, our little Cast Iron Aussie V-8 was manufactured for about 30 years, and actually evolved quite nicely over the time-frame, being introduced in 1969 as a "253"cid engine,(4.2ltr), and then growing balls a couple of years later into a "308"cid (5.0ltr) motor. It finished up being a genuine 5.7ltr OEM engine by the time of it's demise, and the aftermarket guy's could stretch this out to the "King Kong" 6.3 ltr capacity...It's been claimed to be able to produce over 650 hp in 5.7 ltr form, unblown and on 98 Ron Gas. The design was "all-new" at it's release, but it's basically a hybrid in design of your beloved Chevrolet small-block, and the Chrysler/Dodge Hemi designs. Should you want more information about these motors, I'm happy to provide, but there would be hardly any benefit to you or anyone else, except to say that we had our own good thing once, and plenty of them to play around with ! They're still quite a very popular engine to modify as the aftermarket supply of parts is almost never ending, and still evolving. And like your Chevrolet small-blocks, you can build up a complete Holden V-8, without using a single genuine Holden part...

This is why it's so good to speak with you guys, because Australia hasn't developed as rapidly as the States with regards to enhancing Benz Engines ( not like you folks any-how...), they're still very much a niche - market, and their quantities are a lot less here than Stateside. This means that there's a lot less people such as yourselves down here doing what you do.

I sincerely value your experiences that you post up here, ( And so should all who read these posts), and I look forward to hearing from you again !!!

Cheers,

Rasus

gerryvz · Member

Rastaman,

I have owned three M100 motors/cars (rebuilt one 6.3-liter M100.981 engine from scratch in my garage) and there are quite a number of resons why thy are not good candidates for modding. The M100.985 (6.9 liter) in US trim was only 250 horsepower and in Euro trim 279 HP. The US model had 8:1 compression and the Euro versions were only 9:1 or slightly more. You'd have to custom fab pistons to bump compression as a baseline.

Furthermore these motors are not well designed in terms of their breathing characteristics. So while they have displacement, they were not designed to be particularly high performance. I know folks who have installed 6.9s into the R107 chassis -- it's not an easy install. One hindrance is the 12-quart oil tank which is in the right passenger fender on the 6.9 sedan. That would have to be relocated and that would incolve a bit of custom fabbing on a 126.

FAR better to just take an M119 out to 6.0 or 6.2 liters, or a 12-cylinder M120 out to 7.2 or 7.4 liters. These are quad-cam designs with variable-timing intake cams, and have much better breathing characteristics. It would be rather easy to get 500 HP+ from the V12 and the components are more easily available (though expensive). There are very few of the M100 engines left these days.

Hope this helps, mate. I have tons of experience & knowledge on M100s so would be happy to be an adviser if you choose to go that route. But my advice would be to go with a more modern engine rather than the 1950s & 1960s technology M100 engines.

Rastus · UNSTOPPABLE!

Hey SELLC,

I was just thinking about your last post(S), and kind-of got to thinking that with the recourses you have, why you haven't yet considered building up an older M100 engine type with the cast-iron-alloy cylinder blocks for racing ? Surely you could be able to source & then modify perhaps a 6.9ltr engine with the dry-sump, & place it into a more modern 126 - type chassis without too much trouble or fuss ? I would almost bet my balls that you could get the 500+ Bhp at the rear wheels with God-knows how much Torque & reliability. I realize that component or ancilliary replacement parts are expensive for this motor, ( eg water pumps cost around $ 1000:00, though they are rebuildable for less etc etc ) when compared to the M117, but 417 cubes + the cast iron block ought to bring the $ per Hp equation into viable consideration yes ? The thought of a 6.9 SEC sort of makes me toss & turn at night with little rest in my slumber....It would be a remarkable achievement world-wide to read about such a post on this sight, with a say 12:00second 1/4 time (or less) whilst smokin' rubber the whole length of the track...Could this be a possible build or are there too many negatives outweighing this sort of project with these expectations ? I would like to hear your thoughts or insights...Oh yeah, the 6.9 comes out with K-jetronic fuel injection which is very very similar to CISE, so your fueling shouldn't be an issue with Nitrous ?

Cheers,

Rastus

Rastus · UNSTOPPABLE!

Hey guys,

I hope "Stmtt" hasn't put you off placing some more posts up here ! I do appreciate the last few posts from you folks, obviousely you've weighed up the cost-factors for a number of improvements that are possible, and realized the best way to go, all be it with a "chance" involved as to how your motors will handle the Nitrous, and have done yourselves proud in the process, especially after 10 odd years of continued use, race wins, and motors that still run very well ! I thought however that maybe when the time comes for a freshen-up of your internals, you might be swamped with a number of choices to make, and these can make things complicated when a final choice is made about what combination of components will offer you the best results for investment made etc etc. I'm not going to go on like a sales brochure and say do this or that, that's your choice as it will be your money ! However I might throw some light on possible piston choices, only from an advantage of design-type point of view that you may benifit from when the time comes...

Obviously, you have a multiple of choices to look at and consider from a number of makers, and material types, eg,- standard OEM replacements, Hyperuetctic, Forged etc.etc. ( I might point out here that the standard Merc pistons are forged, and Hyperutectic...) However, these already fine standard pistons are designed with a compromise inherant to them, namely to enhance emmision output etc. - and usually in the way of a dished piston crown to lower static compression ratio. Enhancing the compression ratio is where I was going to take this post, as the performance improvement happens right accross the rev-range, and in other areas also....

1) Flat - top type pistons offer no restriction to the incomming air/fuel mixture.

2) Flat - top pistons expose the minimum amount of surface area to the hot burning mixture. ( Picture domed and dished pistons, their surface area is larger...)

3) Re- item 2, this means that the flat - top piston absorbs less heat, and therefore has to dissipate less heat through the rings, and to the oil when compared to other piston types.

4) This results in a cooler running engine, and more energy being transmitted to the crankshaft.

5) Flat-top pistons can be made lighter, resulting in reduced vibration and stress.

6) Optimum or desired compression ratio can be obtained.- ( usually by the height of the piston crown to block height at TDC ).

7) Optimized static engine capacity, - eg. Domed piston crowns reduce cylinder capacity, though increase compression ratio, whilst dished piston crowns increase cylinder capacity,
but they reduce compression ratio.

So anyway people, there goes some more " food for thought ", and incase your wondering what figure to aim for, apparently you can go as high as 12:1, before things start having a reverse effect, but if your car is still going to be your daily driver, 9.5:1 - 10:1 willkeep you running fine as long as you use 98 Ron fuel, to be safe though, aim for 9.5:1.

Cheers,

Rastus

gerryvz · Member

stomette wrote:
HEY GAYRRY ...................... R U TALKIN SHIT ABOUT MY SWEETHEART ****STOMA**** ???????????? HOW DARE YOU !!!!!!!!! FUCKWAD !!!!!!!!!!!!!!!!!!!! AHAHAHAHAHAHAHAHAHAHA !!!!!!!!!!

Quaint how she stands up for her "man" -- LOL !! yawn

stomette · Guru Guest

gerryvz wrote:
You are right on with your assessment of RSJ. He is best worth ignoring and only referencing indirectly, not in a direct way. RSJ is not worthy of direct conversation from anyone on this board, with the possible exception of his pal PowerStroker.

Cheers man !

HEY GAYRRY ...................... R U TALKIN SHIT ABOUT MY SWEETHEART ****STOMA**** ???????????? HOW DARE YOU !!!!!!!!! FUCKWAD !!!!!!!!!!!!!!!!!!!! AHAHAHAHAHAHAHAHAHAHA !!!!!!!!!!

Rastus · UNSTOPPABLE!

Hey guys,

It sounds like we're all feeling the pinch of a lack-lustre economy, and I for one haven't really had my hands under-the-bonnet so to speak for quite a while, except to change and flush the oil in my new(?) Benz...I might as well come out and let you know that it's quite a nice 350SLC from way back in 1973....I made this desicion based on the fact that my Dad (and older brother) have owned Benzes all their lives ( Dad still owns a 280SLC that he bought in 1980. It's done over 320,000 k's and honestly still runs like a dream, and it also wins the odd award from time to time at club events etc.) and the fact that I did my apprenticeship at a Benz dealership as a mechanic many years ago...Right about the time when 560's in whatever guise were brand new...

Yeah, I was probably always going to go for a 560 SL, or SEC, depending on availability and cost, but after being able to source not too many in "fair for age and price condition", I had to start looking for something else, and simply couldn't believe how cheap the asking prices were for the SLC's when compared to the SL's. Some of the SL's I looked at were complete bombs, whilst the SLC's were at least 30-40% cheaper in outlay, with more to choose from, and in much much better condition comparitavely. Being over 6ft tall, the extra headroom and longer seat tract makes for a much more comfortable car to drive for a man of my dimensions. (It's a shame that there's no 500SLC's here in Oz, because they are the pick of the bunch...)

I've only ever owned V-8's, usually of the larger capacities, (5.0ltrs & over), and decided on the smaller Benz V-8 simply because of the facts written in my blurb ages ago,where I'm sure I stated that the 450 engine came into being because the 350 was robbed of all it's power etc etc. This is true, and being in my early 40's now, I have been lucky(?) enough to have been able to drive in my time, both the "pre-pollution" vehicles, and the later emmision compliant ones and well, what can I say, in standard trim, the "pre-pollution "cars go heaps harder ! But ultimately, having owned and loved the bigger V-8's since forever, I wanted a small one because I like revs, and the little Benz V-8's rev like you wouldn't believe, even at legal speed limit's,(eg, 3,600rpm @ 70mph, and 5,000rpm @ 100mph with the std 3.46 :1 diff, & top speed is a geuine 124 mph @ 6,000rpm) so now hopefully speeding ticket consumption will reduce....Yeah right !! The thing that swayed me was that afriend of mine bought a 380SL about 6-months ago, and asked me to check it out etc. etc. And I was really surprised at how tractable and user- friendly the car actually was. I really didn't expect this result or even half the response I got from the little engine ! The 4-speed auto & diff ratio help big-time here...

I'm not going to say that the 350 is the best and you've got to have one, because it isn't ! In fact I really miss the "grunt" of the larger V-8, but the Benz motor is quite a sweet running thing, and actually impresses me with the way it goes about it's business - never ever any fuss. It does everything that my 5.0 ltr can do, (top speed included *200 +km/ph or 125mph), only it takes a little longer to get there. Don't forget though, that you guys never got to get a "pre-pollution" Benz V-8 in any guise, as your emmision laws we're enforced well before you could enjoy them, so you might not completely understand where I'm comming from, but that's OK. ( Possibly the the 6.3 was available for you "pre -pollution", and maybe actually the last of the 108's...I'm not sure...Better ask Ralf Nader...)

The big picture is this, I no longer have the law on my back, I'm saving heaps on fuel, I still have a "fun" going V-8, and I've got a car that's absolutely drop-dead gorgeous ! Apparently the car is capable of a 15.9 in the 1/4, and by the formula that I've posted, this result does equal what the factory claim as it's 200 odd Hp @ 5,800rpm.I still have my old 5.0 ltr, and it's capable of 13.8 in the 1/4 mile,( without nitrous either guys , but it only weighs 1350 Kg) so fortune and time allowing, I may just turn this into a Race Car only for the drag strip, as everythings there and running, all I need is a trailer and someting to tow the bastard to the track with !! Ha ha..Well see...And if this wasn't a Benz site , I'd tell you what lives under the bonnet...

Thanks guys and cheers,

Rastus

SELLC · CERTIFIED POST WHORE

Rastus wrote:
Hey SELLC,

I had no idea until now that you've magaed to get 500 bhp from your 117, awesome man !!! I probably should have asked ( or guessed rather ) that you had already found the engines limitations,

I should mention that I have NEVER had an M117 @ 500 HP, rather 260 + 100 worth of Nitrous (Rated dry jets). The webbing issue at higher than 500+ horsepower does not come from my own personal experiences, rather that of my machine shop who has seen this problem with other customers engines. Of course it is my goal to test this claim, but right now in this economy I stay busy fixing vehicles with much less time spent having fun racing as in my past days.

Just wanted to clear that up. I have however put 400 HP worth of nitrous to a 280 HP Ford 302 engine with a dual stage dry/wet kit and that cast iron engine took the HP without issue or fault. Will an aluminum M117 take that kind of power? We shall soon find out, however it's important to realize that even the aluminum version of GM's LS engines are known to buckle in the 500+ HP arena, thus people are getting into buying the cast iron versions of the LS blocks that are found in trucks and SUVs when HP output gets above the 500+ mark.

Of course new technology allows for amazing things.

Rastus · UNSTOPPABLE!

Hey SELLC,

I had no idea until now that you've magaed to get 500 bhp from your 117, awesome man !!! I probably should have asked ( or guessed rather ) that you had already found the engines limitations, and I sincerely thank you for the info. I honestly thought that the CISE system may have it's limitations in the performance world, not to be critical at all of it's design, ( I've always thought of it as almost perfect, just because of it's simple mechanical workings), yet I based my post on the obsevation that the same engines ( way back in 1975 or so ) actually lost a few horses with K-Jetronic fitted, when compared to the out-going Bosch D Jetronic injection. Enough said...

Also, you're absolutely correct with the balancing procedures ( & the expense involved ) to have this done correctly. I believe the method you've quoted is the "dynamic" type of balancing, and not too many places have the ability to do this, ( at least in my neck of the woods here "Down Under" ). I only offered this "static" type approach of balancing for those who have their motors apart, and might be able to improve on something simply and cheaply from home. I don't know how the Benz factory goes about their balancing "in-house" now-days, but the cranks were ground to a 1 gram to 40mm tolerance "once upon a time", to pass through to the production line, and machined surfaces were within a 3/1000th of a mm consistancy...Also, 1 in every 10 engines were pulled off the assembly-line, and subjected to a number of tests, including Maximum power operation for up to 200 hrs....

Talk about strict quality control, but it does ensure consistancy in subsequent days of manufacture ! And as owners of these cars, you get piece of mind !

Gerryvz, I haven't forgotten about you or your posts, and I wish I had the cash-flow to "enhance" my Benz like you guys have, and I'm taking on-board all of your approaches, and I have to agree, that Nitrous is probably the best "bang for your buck", especially knowing that your car is still running reliably after all these years since fitting it and racing it.

Thanks a whole heap guys, and speak again soon !

Cheers,

Rastus

gerryvz · Member

I've always wondered why all these Benzworld guys who are on this massive quest for additional horsepower, don't just say "screw it" and throw in a 100-shot kit for perhaps $1-1.5K.

Instead you have the likes of ManBoobs McClare spending $12K+ on 40 "net HP", and the motor still not running right or dynoing.

Yes, with ElRogo and ManBoobs as my guides, my de-ASRing *facepalm* should go just swimmingly :)

SELLC · CERTIFIED POST WHORE

Rastus wrote:

Mecedes Benz engines are very well made and designed as you already know. And in case you didn't know, all their crankshafts are made from steel and one forging, and are stress-relieved via the use of the freezing process (I think) called nitriding...All the con-rods are steel forgings also...Very nice...
I agree.. Mercedes Crankshafts are some of the nicest I have ever had the pleasure of holding in my hands. Unlike many others they are always flawless in terms of machieen work. The journals and counter weights are always flawless, never any dimples or craters. Hell they are even more flawless than $2000 4340 performance cranks you see for sale by aftermarket companies. They really are a work of art!
Combined with the 4-bolt Main Bearing fastners, there's a very strong and reliable Bottom-end assembly living there, which is the main reason why they have sustained high rpm reliablity, day after day, year after year...
Actually Rastus, the M116 and M117 engines have a SIX bolt main. 4 on the top of the main and two on the sides that go thru the sides of the block (with the exception of the #1 main cap). ;) Not only that, four of them six are main "STUDS" which are much stronger than a "bolt".
The reason why I'm pointing this out to you, is that I believe you could easily get 400 + Hp out of your 560, and have reliability,
I think people fail to realize that a factory 560 engine is closer to 260 HP with emissions removed. So the magic 400 number was just a small dry nitrous kit away for me. I have had success with a small kit on my 560 back in the early 2000's but after I ripped out a set of engine mounts doing a burn out I decided to leave stuff to a "Race Only" Benz and keep my daily driver as-is. In making that choice I am still driving that car today, EVERY single day without issues or problems as reliable as can be.
but I think that maybe the fuel injection system may end up being your limiting factor, and I would probably ask you to consider a move back to the older Bosh D-Jetronic fuel injection system... Don't laugh !
I would have to disagree. I am VERY impressed with the Bosch system. It supplies so much fuel it's now illegal to use them. Dont forget, this system was used on Ferrari and Rolls Royce too! It's only drawback is poor fuel economy.

Why you may ask ? I would put it to you that the main advantages you would gain come from the fact that you could have your own throttle plate maufactured to your own desired size, to handle the more air-flow required of a higher peak power output at higher RPM, and the fact that you could choose your own capacity fuel injectors to meet these demands, as they're all linked to a common fuel rail loop, and timed to open at varying time intervals, depending throttle position, rpm, air -temp etc etc. via the ECU, which I dare say could be easily(?) modified or mapped rather to suit.
You are not going to find a fuel system more adjustable in terms of getting more fuel than the CIS-E. All these sensors you mention above are a part of this system and can be manipulated.

Another alternative is the "Ma Gee "(?) EFI set up that actually lets you set up your air fuel ratio in real-time as your driving along, with LED display that lets you know in "real-time" what's going on mixture wise at any rpm, load, and throttle position etc. Perhaps a "hybrid" combination of the two is the go ?
CIS-E is already a "hybrid" combination of mechanical and electrical fuel injection. The only time things need to be manipulated is at WOT (Wide open throttle). Anything in between is just cruising and should be left alone.

At the end of the day, this type of injection system will let you determine your own volumetric efficieny (cylinder filling potential), at any rpm, as compared to the CISE system that limits this by having an Air sensor flap (restrictor!) connected to the plunger in your fuel distributer, that lives above your throttle plate.( This system by design gives a progressive cylinder filling ability) This limits the amount of air available to your cylinders, particularly at lower rpms, as you have a "see-saw" effect occuring between the flap and plunger, regardless of throttle position as it's the engines increased negative pressure (within each cylinder that grows with increased rpm ) that pulls this "air flap" down further, allows more air in, and also moves the plunger in the fuel distributor to deliver more fuel through the never closing injectors. It's a great system, but limited, especially for outright performance increases.
I'd have to disagree. Yes fuel injection is more percice in terms of metering fuel, however the CIS-E is FAR smoother in terms of acceloration than ANY fuel injected engine. The feel of a 560, Rolls Royce, Ferrari or Lamborghini using the CIS-E is like no other in terms of how it revs up. The limits I feel are more or less with the aluminum block and heads.
The air metering dish that is attached to an armature to increse the pressure of the fuel distributor via the "plunger" you speak of is quite straight forward. Operating at nearly 90 PSI pressure means you have LOTS of fuel on tap. The trick is forcing that plunger upwards faster, of course that would require the additional air being FORCED in at the same time to maintain an optimal fuel to air ratio. Did I mention that nitrous comes out of the bottle at 1800 PSI? Of course its regulated down, but even if you were to port in a big shot nitrous kit after the air meter that kit would supply it's own fuel, and then of course you have your dry kit that would be forcing that plate down much faster thus applying more pressure to the fuel distributor plunger to give the extra fuel needed. You also have a crude vacuum that is created when the nitrous passes over an orifice that just happens to be connected to the fuel regulator keeping that sucker closed as not to send any of that precious fuel back to the tank. All things told I think you would be at risk of braking the main webbing's of the aluminum block from the sheer power before you ran out of fuel with the CIS-E. You see when your getting 500+ HP that kind of force is literally trying to throw that crankshaft out the back of the engine. The weak link therfore is NOT the CIS-E, its the aluminum block. At least in terms of forced induction anyway.

Also, with regards to balancing your piston/rod assemblies, it's actually easily done with the use of electronic scales that are suitably calibrated,-( or any type of "scales" as long as they're accurate and can sustain the components weight ). All you need to do (after numbering each assy.) is to weigh each piston / rod assy, note the reading of the lightest one, and then bring the weights down of the others by carefully grinding away excess metal from the lower "pad" provide on the bearing cap. When the weights are all equal, the assembly is optimised by being lighter overall, equalized, and you've removed an enormous amount of bearing load (in Nm) that increases linearly as the rpms go up. Your engine will have even more improved reliability.
Simply weight matching your pistons, rods, pins, bearings and rings is NOT what makes for a balanced engine. The crankshaft has to be run out on a balancer, with the exact weight of your match piston assemblies attached. Much like how a wheel is balanced, the crankshaft also has to be balanced, using Malory (welding) to add weight and drilling to remove weight. Simply weight matching the piston assemblies is only half the job. The crankshaft must also be balanced, and it must be done with special weights attached to the journals that are equal to the weight of your matched piston assemblies. Dont forget, your flywheel and balancer must also be attached when the crankshaft gets balanced. This is why many people are clueless when it comes to the REAL cost associated in balancing an engine the right way.

Cheers,

Rastus

gerryvz · Member

Agree that nitrous is good stuff. Yes, I find around 10 1/4-mile runs with my 10-pound bottle is about all I get. I remember how everyone under the sun was insisting I was going to blow up my motor, die in a ball of flame, rot in hell, etc. if I installed the nitrous kit (which is a modified 5-liter NOS brand Mustang box kit), 100-shot. Well, 9 years later my engine is still kicking.... and I'm still around to give RSJ, PowerStroker and ManBoobs McClare plenty of shit.

I do have a bottle heater and remove valve installed on my system, and the bottle is mounted at the correct angle on a custom-fabbed bracket that sits down in the driver's side trunk side well (like a 126 sedan has).

You are right that I have a conservative install. I could jet it upward (I tested the fuel system...remember my nitrous kit is a dry, not wet kit) to 125 HP, but I'd feel uncomfortable going beyond that. M119s are considerably more expensive used than M117s too. I'd love to install a NOS system on my SEC, that would be a nice complement to the 3.07 rear end that I installed about 8 years ago....

But hey, I'm the first to admit I'm an amateur at this stuff, so by no means am I bragging or trying to be something I'm not.

Now, I've got to head out to the garage to "de-ASR" my car.... ;)

Rastus · UNSTOPPABLE!

Thanks SELLC,

You're very much "up-to -date " and I have to agree with you about not being a fan of turbos or blowers. And thanks for bringing me up-to-date with who-what-&-whens of what's getting certain times down the 1/4 with the trade-off of top end speed. It does put a vehicles "over-all" abilities into perspective. Wind resistance is something that's always underestimated, and often something you can't do a lot about as your basically "stuck with what you've got " !

Mecedes Benz engines are very well made and designed as you already know. And in case you didn't know, all their crankshafts are made from steel and one forging, and are stress-relieved via the use of the freezing process (I think) called nitriding...All the con-rods are steel forgings also...Very nice... Combined with the 4-bolt Main Bearing fastners, there's a very strong and reliable Bottom-end assembly living there, which is the main reason why they have sustained high rpm reliablity, day after day, year after year...The reason why I'm pointing this out to you, is that I believe you could easily get 400 + Hp out of your 560, and have reliability, but I think that maybe the fuel injection system may end up being your limiting factor, and I would probably ask you to consider a move back to the older Bosh D-Jetronic fuel injection system... Don't laugh !

Why you may ask ? I would put it to you that the main advantages you would gain come from the fact that you could have your own throttle plate maufactured to your own desired size, to handle the more air-flow required of a higher peak power output at higher RPM, and the fact that you could choose your own capacity fuel injectors to meet these demands, as they're all linked to a common fuel rail loop, and timed to open at varying time intervals, depending throttle position, rpm, air -temp etc etc. via the ECU, which I dare say could be easily(?) modified or mapped rather to suit.

Another alternative is the "Ma Gee "(?) EFI set up that actually lets you set up your air fuel ratio in real-time as your driving along, with LED display that lets you know in "real-time" what's going on mixture wise at any rpm, load, and throttle position etc. Perhaps a "hybrid" combination of the two is the go ?

At the end of the day, this type of injection system will let you determine your own volumetric efficieny (cylinder filling potential), at any rpm, as compared to the CISE system that limits this by having an Air sensor flap (restrictor!) connected to the plunger in your fuel distributer, that lives above your throttle plate.( This system by design gives a progressive cylinder filling ability) This limits the amount of air available to your cylinders, particularly at lower rpms, as you have a "see-saw" effect occuring between the flap and plunger, regardless of throttle position as it's the engines increased negative pressure (within each cylinder that grows with increased rpm ) that pulls this "air flap" down further, allows more air in, and also moves the plunger in the fuel distributor to deliver more fuel through the never closing injectors. It's a great system, but limited, especially for outright performance increases.

Also, with regards to balancing your piston/rod assemblies, it's actually easily done with the use of electronic scales that are suitably calibrated,-( or any type of "scales" as long as they're accurate and can sustain the components weight ). All you need to do (after numbering each assy.) is to weigh each piston / rod assy, note the reading of the lightest one, and then bring the weights down of the others by carefully grinding away excess metal from the lower "pad" provide on the bearing cap. When the weights are all equal, the assembly is optimised by being lighter overall, equalized, and you've removed an enormous amount of bearing load (in Nm) that increases linearly as the rpms go up. Your engine will have even more improved reliability.

Cheers,

Rastus

SELLC · CERTIFIED POST WHORE

I disagree Gerry... I find that Nitrous, when used properly is able to be used when needed to achieve victory in almost any situation.

There are things such as large bottles, bottle warmers, and remote bottle openers that allow you to pretty much have nitrous on tap whenever its needed.

I understand that you have used small nitrous kits Gerry, and they are pretty safe. Hell I used to run back to back 1/4 mile passes all night long with my Mustangs back in the 90's. These small kits use relatively small amounts of nitrous and you can get about 12-16 1/4 mile passes out of your standard bottle. That's a lot of wins considering no one races for free, so your first win pays for the other 15 passes.

What I found with the small nitrous kits is that it becomes not enough after awhile, so I made a dual stage kit. The first kit was my reliable dry kit with 5/16 or so hose. The next kit was a BIG SHOT kit with a 5/8 hose. The big shot kit was wired thru all the safeties of my dry kit so it would shut down in the event anything went wrong. What I can tell you is this... With 400 HP worth of nitrous it's like NOTHING you ever felt. The speed in which the RPMs climb is almost mind blowing. There is NOTHING like it and I have driven vehicles with Dual Turbos, SuperChargers and Blowers.

Hands down nitrous oxide is the best bang for the buck in terms of competive racing on the street or drag strip. It is introduced to the engine at below freezing tempratures making for a dense air charge, and it does not take away any power from the engine to opperate, either in drag or restriction.

Nitrous is good stuff.

gerryvz · Member

The best I've been able to do with my E500 with nitrous is a 12.89 second quarter mile, at a little over 108 MPH. The stock time for said car, normally aspirated, is 14.1 at a high-99 MPH speed.

Nitrous is the shizzle, but it's only usable for short acceleration runs. It would be nice to have all that additional power on tap all of the time, say with a supercharger. A local shop owner here in Houston with a 1993 500E installed an Albrex supercharger. I took a lot of photos of that car. Unfortunately the photos caused quite a few of my board members to get woodies.