Kirks Car:

Kirks 185 pulley was installed by CPT (chicago performance) around april of 08. He has put approx 10k miles on the pulley since the install.

His most recent dyno tune (or any tune for that matter) was done by LET at the end of the summer last year. It is a standard stage 2 tune, and not agressive like mine. (I call Kirk a puss for that but thats besides the fact)

The car was brought to us in the beginning of March to install a catch can and Plenums per kirks request. The catch can install was quick and easy, the plenums on the other hand turned into a headache.

We installed the plenums and started the car. Seemed fine.
So, we brought it next door (seperate performance company) to run it on the dyno and so we could tune it appropriately. The first pull is strong, but seems to be missing the top end. Run another pull to gather the appropriate data before the tune and end up shutting it down mid pull.

The gasket on cylinder 4 is blown out of the plenum. We pulled the plenums and went through the process to see what was going on. The gaskets were both missing from one side of the plenum. We tried some of the factory mercedes gaskets, no seal. We removed the phenolic spacers and tried mb gaskets, no seal. We tried everything and could not get a proper seal. Now we have a rough idle. Further troubleshooting shows compression problems on 4. We put the factory plenums back on, car is the same.

We then handed the car over to the neighbors to see if we were missing something. They take the car for the day, and find the same results. They cannot find anything obvious that is wrong with the car. They are showing compression issues as well, and now we can't flash it as we don't know whats going on.


This is the message that was sent to rob on March 6th.


Rob,

Here is what we have done. We originally installed the plenums using the needswings gaskets. We couldn't get a proper seal on the unit and the car is now running like $%^# due to possible boost leak / misfire. We then swapped gaskets to the mercedes c32 gaskets (still using his phenolic spacers) and still could not get a proper seal. We then pulled the spacers off and used new mercedes gaskets. The car was still running poorly, but better than it did. We did noticed that with the car running we could lean heavily on the plenum and get a pitch change for what we expect was a leak in the seal. We removed all components once again, and tried gasket sealer on all components. We let that sit for an hour and put everything back together. It still was a bit shaky at idle. We checked vacuum pressure, swapped injectors, swapped plugs, continuity tests, changed wires, cold packs, ran STAR diag on the car but we kept seeing a slight misfire on cylinder 4. We checked the throttle body and it was fine, checked the sprint booster and removed it for testing, and we still did not find an issue.

At this point, we are removing all parts per Kirks request and going back to the way the car was. I honestly can't figure this one out. We did the same thing on mr x's car and it was a 30 minute job with none of the issues that we ran into here. We put the plenums on a piece of glass and the one is out of level by quite a bit.

Any thoughts would be appreciated.


I called Rob personally, and the stand up guy that he is tells me to send the plenums back and he will re-deck them, clean them up (by now they have been in everyones hands), and get them right back to us/kirk.


Back to the issue at hand.

Leakdown tests on the motor are not good, and compression is down as well. We made the decision to pull the heads. Not pretty. We pulled the engine and after an hour or so see the issues.

We have had 3 different mechanics look at the engine out of the car (at different times and without us telling them our thoughts) and they are all coming to the same conclusion.

Boost leak. The leak from the plenums caused by the improper seal caused the condition on that cylinder, causing detonation and damage. Boost is measured before the plenums. The missing part of the piston that you see in the picture is what was scratching the cylinder wall. The pistons could have very well been used and abused by running the car hard under cold conditions and bouncing the red line. But, the timing on this particular event is what is the deciding factor. I am thinking that he might have gotten a little hot/possibly even lean in that cylinder and caused issues.

Eurocharged / LET replaced Kirk's motor using one of our low milage (5000 miles) SRT6 motors we had in the shop. We didn't charge Kirk for the parts, nor have we asked him for anything in return. He offered to pay for some of the labor, being the stand up guy he is.

So, moral of the story is...be good to your engines and remember that modding itself carries a risk.

 

Thank You JAKE...and Thank You to all at EUROCHARGED.

 

no problem kirk, Im sorry it took so long, but when something like this is released do to a product, we needed to make sure we followed the proper steps.

that and don't kill my other engine

 

Jake,

I hate to be a dork, but would you do us non-mechanics a favor and point out the damaged areas in the pics. I've never seen the insides of a motor up close and personal, so I don't know what it should look like.

Thanks!
Tom

 

Sorry tom, I should have done that. I was trying to make the post as acurate as possible and lost sight of it being an educational tool.

The problem areas are the piston pictures that show that there is a chuck of metal missing.

And the pictures of the 3 holes on the engine. If you look closely you will see that the cylinder walls are scratched pretty badly. There is a very tight tollerence there, and any kind of scratching will cause issues.

Make sense?

 

Jake and Kirk, thanks for sharing the mods and findings. Agree with Bulldogger that logically, a boost leak should lead to a rich condition (which can also kill a motor, score cylinder walls, etc.) - but definitely sounds like the boost leak is the primary culprit here.

Hypothetically, if this happened to someone and they didn't have a shop in their backyard with a spare motor just lying around ... what could they expect to pay in P&L to get back on the road? Just ballpark.

Last question - it was mentioned that this motor's going to be rebuilt... what are the plans for dealing with the special cylinder wall coatings (alusil or nikasil, can't remember which one)?

Thanks again for sharing/posting up all the info! Very useful stuff for the forum to be aware of.

 

The boost leak allowed too much fuel, you might have washed the block wall with fuel and hung the rings causing them to stick add in the extra heat from from rich A/F ratio and you break the ring lands as pictured. If you send an oil sample to Blackstone labs you can find out what condition the oil was in. It should be broken down if the car was running lean and causing excessive heat. If the car was running lean I would have expected a hole in the top of the piston

 

Not a problem. You can understand why it took so long to get out but with what was being released as why it happened we needed to make sure

Well, according to AMG the motor is a giant paperweight. But, that being said with the rest of the world not having gobs of $....

The cylinders will have to be bored out and sleeved. The boring will remove the scratches, and the sleeves will take up the missing space from machining.

new pistons will have to be ordered or made.

The cheapest used engine we have found was $3500

I will let everyone know as we start the build process. We were always talking about having a new set of internals built, but the cost of pistons alone was 1500, so we kinda put it aside

 

lets just say we share the same thinking...no white mess on the piston either...

 

Riot, lounge, thank you very much for the pics and honesty.

Are you suggesting the boost leak from the plenums not seating properly caused the piston ring lands to crack? What cylinder number was that? Driver or passenger side?

 

Washing the cylinderwalls down with fuel is never a good thing either.

 

Reading the rest of the thread you beat me too it, right what I was thinking.

 

If you are running so rich that the cylinderwalls get washed with fuel, you loose lubrication, cause friction and eventually disaster.

Interesting thread, thanks for the pics.

 

unfortunately yes....because of the unlevel deck.

cyl 4 was teh one that showed first...

 

What torque specs did you use when installing the pleniums?

I rasied a concern about this issue sometime back.

https://www.crossfireforum.org/forum...t=28921&page=2

 

Too funny, that was my first thought, but they were torqued to 7 as spec'd

We took one of the plenums off the car and placed it on a piece of glass. We were able to rock it back and forth noticabally, as well as fit feeler shims in the gaps when leaning on the plenum from the top.

That was probably the deciding factor for Rob to take them back and have them properly re-decked.

We received the fixed units and performed the same test on the glass. No movement whatsoever. The other ones were definately out quite a bit.