02turbocamaro

I have a 408 stroker built with diamond pistons and eagle rods. ARP hardware. Forged Crank. 215 Trick flow heads. Meth. Best of the best was put into this car. I wanted to keep A/C, so I did a rear mount set up. 81MM comp turbo. The car has been blown 2 head gaskets in a total of 1000 miles at only 11-12lbs of boost. WTF IS GOING WRONG?! Nobody seems to have found the actual culprit of my problem. Any suggestion on what I should start to look at or consider?! ANY and ALL help would be great guys!!

HexenLord

More info?

A/F Ratio, compression, what fuel, pushing water through gaskets?
Head surface checked? which head gaskets are you using? head studs or head bolts?

There's a lot you left out.

02turbocamaro

I was more or less waiting for what people want to know, compression is 10.5:1. 93+meth. Blowing head gaskets out the side. Head surface has been checked everytime. Using cometic head gaskets. ARP head studs. A/F ratio is normal.

Blown06

iTrader: (32)

When using cometics, just checking for flatness isn't necessarily the only thing. They need to be fresh cut and a certain ra finish.

...and I'm gonna doubt they are "fine" if they weren't surfaced after the first pop.

Although, popping gaskets at 11-12 psi sounds like it could be a tune up issue. How much timing is in it?

JAX04

iTrader: (17)

Im curious what the specs are on that turbo... Specifically the turbine and housing

TrickrTreat

iTrader: (3)

ya, still alot of info being left out, particularly turbo specs, timing info ,intercooler setup ,also where your referencing your boost for your wastegate, and actual boost reading vs actual boost at intake.

do you have a build thread?

Old Geezer

iTrader: (3)

How about posting the tune file, and some data logs.......
"A/F is normal".. what might you consider "normal"??

hellbents10

iTrader: (10)

I would bet the tune up is way off, and Chinese parts are not the best of the best.

asubennett

iTrader: (6)

I would say timing at peak torque is the issue if blowing at only 11 or 12lbs.

You said head was checked to be flat -
Is block deck surface flat?
Where is boost being referenced?
What are head studs being torqued to?

stevieturbo

Who has actually looked at it ? Who is tuning it ? And who is doing the work ?

Provided the gasket surfaces are perfectly flat and with a good smooth finish, that aspect should be all good.

Then you must be torquing them correctly, and of course with an accurate torque wrench.

And once the simple mechanical installation is good, ensure whoever is tuning it is competent.

corpserodeo666

iTrader: (12)

What size AR are you running on the turbo with what size DP?

02turbocamaro

The tuner is sam miller here in dallas. I have never been able to get any paperwork on the tune with either time. Not to happy about that situation. Engine has been completely remachined both time. A/R housing is a 1.52, the first a/r housing was a .96 . Sam Miller put the boost reference at the turbo in the back. Wasn't really happy with that. Unfortunately some of my information is not available because it was not given to me when I asked for it. The engine builder is Kyle Thompson in Nevada Tx. Also this is a STS rear mount turbo. I'm also running a 115 head and trying to get ahold of trick flow and see if it should be a 220/225 like they say on the website. Sorry for the lack of information because It has been very hard to get it from the people doing the work or supplying the parts. I have learned so much what NOT to do next time!!!

Atomic

iTrader: (37)

Tune is off.

You can keep 4 bolt heads down at 30psi if the tune is good.

stevieturbo

What's a 115 head ?

trans2000am

iTrader: (49)

Seeks like a large AR for a rear mount setup see if u can get ahold of a data logger

LLLosingit

iTrader: (4)

I bought a Lq9 408 that blew a head gasket with under 15lbs of boost, Then after the repair it broke a main cap taking out the crank. To much timing was the end conclusion. All that pressure has to go somewhere. It doesn't matter how good your parts are something is going to give with a bad tune. Hopefully you can find the problem before it does some real damage.

Silver408z

iTrader: (1)

Sam is known to be a very good tuner. It would be highly unlikely that he has to much timing in it. Not saying that the tune should not be double checked, just that it would be a big surprise it that was the issue.

02turbocamaro

I meant 215 heads instead OD 115. I have confidence in Sam but mistakes happen. I really think it needs to be data logged while building boost on the road. Not saying it is Sam at all, I just won't rule out everything. Trick flow says heads are fine. I'm having another machine shop check engine. Taking extra precautions with every step.

stevieturbo

If the heads are in good order and surface flat, they are not the problem.

rkreigh

11-12 psi using 93 pump gas is alot at that compression ratio and with too much advance you are likely getting detonation and you are FORTUNATE that you are just blowing HG

need to data log that rascal and watch for knock

the big bore blocks seem to be a bit more touchy there

cam timing, ignition timing, compression and boost are all leading up to more cyl pressure than your setup can seal.

also as mentioned above, if the block deck and cyl head surfacing aren't up to par (warped, too smooth, ect) it could have basic sealing problems that the boost quickly uncover

good luck! I would seek out a second opinion to look over the tune

if the tuner isn't being open with you about the setup, seek another.