Hey Guys, anyone know what the minimum compression needed to run a 292 engine is? I used the search feature but have found different answers. Some said 100-125 psi and others had trucks running on 70-80 psi. I've had my truck sitting for a long time and my compression is as follows:

1-70
2--80
3-80
4-90
5-95
6-90
7-75
8-90

 

Those are pretty low. A newly rebuilt engine is about 150. Will it run, maybe. If it has been sitting for a long time, you may put some MMO or ATF in each cylinder and let it sit for several days and if there are any rings sticking, that will help. How many miles?

 

Those numbers can be normal for an engine that has not run for many years. The rings & cylinder walls are very dry.

If you can get it started & running for even a few minutes, it will pump oil to all of the necessary places. Compression would then be much higher

 

Well I got some smoke to come out of the exhaust today and a backfire or two but not much of anything else. I'm waiting for my battery to charge up and I'll try again. The engine turns easy by hand. The truck never really ran right since I've had it. I just recently did a valve job on it , I figured it was the least I could do for the old gal. Hopefully I can get her to fire up. I can't really afford a rebuild at the moment.