Help: new engine or rebuild?
https://mbworld.org/forums/w211-amg/...k-stomach.html

Regardless, $2K sounds reasonable enough.
I get that the enormous amounts of heat can melt pistons. So larger pulley>more boost>more heat= problems.
Questions:
1. How and why does cylinder 8 fail?
2. Does pulley "brand" matter or is it the size?
3. Does upgrading your HE remove a little bit of the risk of this happening or does it just ensure you run more consistently (IAT down)?
4. I have a 180mm pulley and no cooling mods. Can I drive from LA to Vegas later this month?
Thanks!
I get that the enormous amounts of heat can melt pistons. So larger pulley>more boost>more heat= problems.
Questions:
1. How and why does cylinder 8 fail?
2. Does pulley "brand" matter or is it the size?
3. Does upgrading your HE remove a little bit of the risk of this happening or does it just ensure you run more consistently (IAT down)?
4. I have a 180mm pulley and no cooling mods. Can I drive from LA to Vegas later this month?
Thanks!

https://mbworld.org/forums/w211-amg/...k-stomach.html
There is so much bull**** and misinformation its hateful.
and LOL at the guy who thinks plastigauge is the way to go thinking rebuilding an engine is easy.
The Best of Mercedes & AMG
I get that the enormous amounts of heat can melt pistons. So larger pulley>more boost>more heat= problems.
Questions:
1. How and why does cylinder 8 fail?
2. Does pulley "brand" matter or is it the size?
3. Does upgrading your HE remove a little bit of the risk of this happening or does it just ensure you run more consistently (IAT down)?
4. I have a 180mm pulley and no cooling mods. Can I drive from LA to Vegas later this month?
Thanks!

The proper way to develop tunes for modified cars is to put egt probes in each cylinder header tube to figure out if any cylinders run leaner or hotter than others.
From what I've seen from powerful supercharged V8s, the routing of the fuel rails can cause certain cylinders to lean out, as can intake design (although thats less of a problem with a pos. displacement blower). Also, depending on how the coolant flows and how it is routed back to the radiator can have a big effect on heat in certain cylinders.
For example, on modular mustang Cobra DOHC V8s, the coolant would dead end on cylinders 7 and 8 because there wasn't a direct route back to the heater core in that case. So, the fix for that was a kit that removed a freeze plug, and added a fitting and tubing to the heater core. This causes much more even cylinder cooling, and a lesser chance of detonation.

Didn't we already have this conversation? Since you obviously think I'm an idiot, why not post some actual info that may be helpful for the OP. I'm guessing it'll go like this:
"take out your check book, fill out a new check but leave the amount blank, then just hand it over to the MB dealer and your car will come out running perfectly in no time".
I can't stand people like you who think everything in an AMG engine must be done with an electron microscope and with Steven Hawking helping you to build it. Guess what? I'm the guy who got flamed for cutting into my crank shaft with a dremel to put a long key since I sheared my oem one ( which I didn't fix and it's still screwed up ) and put a wobbly 180mm pulley on. And guess what? IT STILL WORKS PERFECTLY!
The proper way to develop tunes for modified cars is to put egt probes in each cylinder header tube to figure out if any cylinders run leaner or hotter than others.
"going to be a head turner"
I think that's the main point.
As far as plastigauge, debating its accuracy is as old as the hills. The only real reason it's used is primarily because people don't want to spend the money on a set of mics.
GM may say it's okay to use in their workshop manuals, but that doesn't mean they don't use micrometers either. Plastigauge can be a good measuring tool as a back up but most serious engine builders don't rely on it 100%. It's good for double checks in certain applications. And plastigauge is only as accurate as the person measuring it, a dial gauge is more easily read. Plastigauge is better than nothing obviously.
I know one of the top Porsche engine builders (he's in Torrance CA) and he uses mics, so to say that the "industry uses plastigauge" is a bit misleading. Maybe "sometimes uses it in conjunction" is the better way of saying it.
fwiw, here's a 2-year old article on "how accurate is plastigauge?" http://www.carcraft.com/techfaq/116_...ter/index.html
"It's a tough call. If you only plan on ever building one or two engines in your life, it's difficult to justify spending big dollars on specialty engine tools like a micrometer and a dial-bore gauge. But the truth of the matter is that if you spend the coin on the right parts, it just isn't worth it to risk not accurately measuring clearances. Many car crafters still rely on the trusty old Plastigage to keep them out of trouble, but just how accurate is this simple little tool? We wanted to find out."
"After we torqued the rod cap and then removed it, we used the Plastigage package to compare its width to a particular clearance. While our careful mic measurements indicated a clearance of 0.0031 inch, the Plastigage indicated a much tighter 0.0015-inch clearance-or roughly half of what we mic'd. We double-checked our measurements, but the results were within 0.0001 inch."
I think that's the main point.
As far as plastigauge, debating its accuracy is as old as the hills. The only real reason it's used is primarily because people don't want to spend the money on a set of mics.
GM may say it's okay to use in their workshop manuals, but that doesn't mean they don't use micrometers either. Plastigauge can be a good measuring tool as a back up but most serious engine builders don't rely on it 100%. It's good for double checks in certain applications. And plastigauge is only as accurate as the person measuring it, a dial gauge is more easily read. Plastigauge is better than nothing obviously.
I know one of the top Porsche engine builders (he's in Torrance CA) and he uses mics, so to say that the "industry uses plastigauge" is a bit misleading. Maybe "sometimes uses it in conjunction" is the better way of saying it.
fwiw, here's a 2-year old article on "how accurate is plastigauge?" http://www.carcraft.com/techfaq/116_...ter/index.html
"It's a tough call. If you only plan on ever building one or two engines in your life, it's difficult to justify spending big dollars on specialty engine tools like a micrometer and a dial-bore gauge. But the truth of the matter is that if you spend the coin on the right parts, it just isn't worth it to risk not accurately measuring clearances. Many car crafters still rely on the trusty old Plastigage to keep them out of trouble, but just how accurate is this simple little tool? We wanted to find out."
"After we torqued the rod cap and then removed it, we used the Plastigage package to compare its width to a particular clearance. While our careful mic measurements indicated a clearance of 0.0031 inch, the Plastigage indicated a much tighter 0.0015-inch clearance-or roughly half of what we mic'd. We double-checked our measurements, but the results were within 0.0001 inch."
Regardless, you can use whatever you want. I'll use whatever I want. It's worked flawlessly for me for years and on many builds. I have yet to have an engine failure that wasn't due to excess power. I also don't believe in taking out a blank check and having it solve all my problems.
We are off topic once again. Sorry OP, I'll end it.
"take out your check book, fill out a new check but leave the amount blank, then just hand it over to the MB dealer and your car will come out running perfectly in no time".
I can't stand people like you who think everything in an AMG engine must be done with an electron microscope and with Steven Hawking helping you to build it. Guess what? I'm the guy who got flamed for cutting into my crank shaft with a dremel to put a long key since I sheared my oem one ( which I didn't fix and it's still screwed up ) and put a wobbly 180mm pulley on. And guess what? IT STILL WORKS PERFECTLY!
In fact, building an engine properly, including measuring all necessary parts with the correct tools takes skill. Just about anybody could take the parts and bolt them together if I gave them a list of what to do, but thats not exactly doing it right.
As for AMG engines, I'm actually on the other end of that spectrum. I don't think there is anything particularly special about them. However, with the exception of maybe a plain old small black chevy, I would use the correct tools and a "clean room atmosphere" to assemble the engine...from a honda 4 banger to a ferrari v12.
as for your crank snout...it will work perfectly until it doesn't. Then when it takes a chunk out of the crank, you'll be screwed. You didn't have much choice, but don't pretend that your solution is a great one.
I don't think there is an engine on the planet in which each cylinder performs exactly the same.
Had tuners used the 8 egt probes, they would have seen that the number 8 cylinder probably runs leaner or hotter than the others. Then what you do is tune for the most dangerous cylinder. While race cars have the ability to adjust a/f for each cylinder, on a street car, you create a margin for error by adding enough fuel and retarding timing to the point where your most dangerous cylinder is still ok.
By using a single wideband or EGT, you simply wouldn't have a clue.
fwiw, here's a 2-year old article on "how accurate is plastigauge?" http://www.carcraft.com/techfaq/116_...ter/index.html
[/I]

THE #8 CYLINDER ISSUE IS A FUEL STARVATION ISSUE!!
It has very little to do with the tunes since the major players that are writing these files have done so for quite few years. This topic has been covered over and over but it was always about blaming the tuner when, in reality, it was a fuel delivery issue. More to do with volume in the rail and not pressure.
As Oliverk stated, the only way to be able to see this issue would be to install EGT probes in each primary and see how the #8 cylinder temp is greater than every other cylinder.
Even if you did have long tubes installed you would have eventually had the same failure. There is only 1 proven solution to this issue and it has worked flawlessly since it has been on the market.
High speed runs through 3rd gear and deep into 4th(where the transmission is 1:1) are very high load situations and, if done repeatedly, will cause this failure.
Last edited by TTMotorsports; Jun 12, 2011 at 06:18 PM.
It has very little to do with the tunes since the major players that are writing these files have done so for quite few years. This topic has been covered over and over but it was always about blaming the tuner when, in reality, it was a fuel delivery issue. More to do with volume in the rail and not pressure.
As Oliverk stated, the only way to be able to see this issue would be to install EGT probes in each primary and see how the #8 cylinder temp is greater than every other cylinder.
Even if you did have long tubes installed you would have eventually had the same failure. There is only 1 proven solution to this issue and it has worked flawlessly since it has been on the market.
High speed runs through 3rd gear and deep into 4th(where the transmission is 1:1) are very high load situations and, if done repeatedly, will cause this failure.[/QUOTE]
what is your one solution?

Didn't we already have this conversation? Since you obviously think I'm an idiot, why not post some actual info that may be helpful for the OP. I'm guessing it'll go like this:
"take out your check book, fill out a new check but leave the amount blank, then just hand it over to the MB dealer and your car will come out running perfectly in no time".
It has very little to do with the tunes since the major players that are writing these files have done so for quite few years. This topic has been covered over and over but it was always about blaming the tuner when, in reality, it was a fuel delivery issue. More to do with volume in the rail and not pressure.
As Oliverk stated, the only way to be able to see this issue would be to install EGT probes in each primary and see how the #8 cylinder temp is greater than every other cylinder.
Even if you did have long tubes installed you would have eventually had the same failure. There is only 1 proven solution to this issue and it has worked flawlessly since it has been on the market.
High speed runs through 3rd gear and deep into 4th(where the transmission is 1:1) are very high load situations and, if done repeatedly, will cause this failure.[\quote]
what is your one solution?

Running from the police and speeding are two very different things. Also, I don't whine when I get pulled over for breaking the law. If I were to whine about it, your point about hypocrisy would hold some water.
I like to drive fast, the S500 has a stupid 130mph speed limiter. I don't run from cops, and I accept the consequences of my actions.
the funniest part about your whole post is that I know more about the cars in question then the people who own them.











