Hey guys,

I'm going to be doing a compression/leakdown test this coming saturday to assess the motor's condition. It's got 88k miles on it stock block and will be TT'd shortly provided the results of the comp/leak tests check out. My question is what would be acceptable results for these tests. I want to go in with some knowledge before hand. Thanks for any input

Also any recommendations to check the health of the head gaskets without pulling the heads? (car doesn't overheat but one of my friends did tell me he saw white smoke briefly come out of my exhaust during my power shifting. This was at a time when it was raining pretty good so I can't tell if it may have just been the exhaust pulses leaving the tail pipes and hitting the asphalt and misting up water. So this is something I definately want to check)

 

The brief smoke on a downshift or upshift is nothing to worry about.

Solid compression numbers on a warm stock engine are 190-200psi. Anything less than 160psi and I would be concerned. Also look for variations between cylinders, as a variance of more than 12psi between cylinders is also concerning.

For leakdown, I like to see 5-8% leakdown from a stock engine...more than 10% is concerning, and more than 15% is really bad for a stock engine.

 

awsome thanks for your input Sharif

 

I was going to do the same thing also as my Z past 100k and was thinking of A TN kit......Sharif chime in on this as you know me in person. I have not driven her hard at all and amazingly I am on the stock clutch and tranny.

 

A well maintained stock engine, properly maintained, can easily last 150-200K miles.

I think you guys are doing the right thing, as its always best to be cautious, when attempting to boost a higher mileage engine. More than likely, your engines are fine, and I would have no reservations about going FI. Keep us posted.

 

Tony WLD 350z ( Grumpy ) was telling me as long as I keep it at stock boost I will be ok pending a compression test. So I will do the compression test and then see what steps I take toward my FI adventures. On another note when are you ever coming back to cali so we can do another dinner.

 

At higher altitude, the compression numbers will be lower than at sea level...

on a perfectly healthy motor at 5500ft altitude, the compression test will show 160-170psi

...just thought I'd share


-TODD

 

I'll be at SEMA in Oct, so why dont we meet up there?

 

I didn't even think about that, thanks for the insight Todd.

 

It's possible I may be there with turbonetics...