ok so i bought my s and was told by the owner that the rings were bad but i dont think the rings are the actual probleme. the car was tuned at king motorsports and only made 248whp @ 6.5 psi (gate spring was 8 psi) and i was told by the previous owner that they were unable to raise the boost at all and were unsure why so they performed a compression test and a leak down test...
results-
cyl #1- 210psi comp
28% leak down

cyl #2- 191psi comp
41% leakdown

cyl#3- 205psi comp
41% leak down

cyl #4- 190psi comp
20% leak down

while its obdvious theres a leak down issue i dont believe that the compression numbers are that far off given stock is supposed to be 228 +- 28 psi.

after getting the car i noticed it had some serious lifter noise so i pulled the valve cover and noticed some of the primary lobes on the intake cam were badly scared. i also looked over the turbo install noticing that there was a bolt missing from the turbo to the manifold and also noticing that the waste gate was so loose that it was basically ready to fall off (i guess that explains the 6.5psi and low numbers).

my question to you is would it be worth it to put a new head on this block given the compression numbers are decent or should i just say F it and buy another motor?

 

bump

 

IF you did a leak down you should have been able to tell if the valves were not sealing or the rings. Listen or feel for air leaking into the intake, exhaust manifold, and pull the oil fill cap and check for air coming from the crankcase.

Turbo cars can cover up valve seal issues pretty easy with boost.

 

difficult to detect while driving...but the leakdown should tell more.

I turned 200psi across all cylinders normally so I'm on the -28psi side.. In any case it sounds still ok.

Did you do a valve lash check (valve adjustment)?

The issue is that it sounds like it needs a new cam and possibly some other head work.... the bottom sounds fine.

-Greg

 

If you have scared cams at some point this engine had mechanical over-rev and failed retainers. They might still be failed I would check that before you run that engine anymore. Because if it wasn't fixed your engine will soon swallow a valve without proper repair.

 

^ scary.

 

Scary but true check out this thread pay and close attention to Woodworks post


https://www.s2ki.com/forums/index.php?showt...0&#entry4486856

 

thanks for all the info guys... i no longer drive the car since i was planning on putting a motor in over the winter but i figured why drop the extra cash if i can just put a head on it. as for the leak down test i didnt do it myself it was done by the tuner at king and all he ever told me was that he thought it was the rings which wouldnt make much sense if it still had solid compression..

 

read the thread posted above great info! seems to me like the guy who previously owned it probably over rev'd it which is no surprise since he seemed to be a real intellectual giant lol.

either way seems like im going to just put a fresh head on it and a 2 or 3mm head gasket and get a retune in spring.

 

^ :iagree it was great info. I'm gonna check my retainers etc. today.