Fresh engine. Break-in, leakdown test questions.
06-23-2006, 09:42 PM
#1
Fresh engine. Break-in, leakdown test questions. I took my new 402 for its maiden voyage a few nights ago. I stopped at a friends house to put the car on a lift and adjust the exhaust and noticed that there was oil leakage coming from the rear seal area. So after 20 miles, I got the car back home and pulled the tranny out of it. I have a new rear seal ready to go in, but this all got me to wondering whether it might have just been excessive blow-by from the rings not seating yet. I recall looking at the breather when I first started the engine and noticed a small amount of vapor blowing out. It'll tick me off if I pulled it and didn't need to, but I'd like to think better safe than sorry. Nobody wants to follow someone with an oil leak at the racetrack 
So I guess what I'm wondering is?
How long does it take for the rings to seat in a new engine (using dino oil for break ins)? I mean sufficiently seated, not marginally.
How long should I wait (how many miles) before its worth it to do a leakdown test on the motor? Should I do it on a cold or warm motor for most useful results? How many seconds do you maintain pressure in the tester before taking your reading? This motor has Hellfire rings gapped for a 200 hp shot of nitrous so I don't know that I'd expect stellar numbers... Whats acceptable for that kind of ring?
Sorry if they seem like simple questions, but I just ordered the tester, and won't have it for at least a week so I haven't read the instructions yet.
So I guess what I'm wondering is?
How long does it take for the rings to seat in a new engine (using dino oil for break ins)? I mean sufficiently seated, not marginally.
How long should I wait (how many miles) before its worth it to do a leakdown test on the motor? Should I do it on a cold or warm motor for most useful results? How many seconds do you maintain pressure in the tester before taking your reading? This motor has Hellfire rings gapped for a 200 hp shot of nitrous so I don't know that I'd expect stellar numbers... Whats acceptable for that kind of ring?
Sorry if they seem like simple questions, but I just ordered the tester, and won't have it for at least a week so I haven't read the instructions yet.
06-24-2006, 07:24 AM
#3
A quick tattle tail for blowby with the stock pcv system in place is oil in the intake it only takes a second to look in the intake. I see you said a breather so that may not be applicable. I to suffer from alot of blowby on my engine.(20% on a cold engine) the rear main leaking has always been a tattletale for me. it would leak on my stock engine when i was spraying the **** out of it. I finally got it to stop leaking on my new engine by using the ls6 valley cover to the TB plus venting both valve covers to atmosphere.
