rb compression

[driftmyke]

im picking up a rb clip from venus auto tomorrow at 9:30 and im gonna have the guy compression test the motor in front of me cause i dont trust them.

my question is how much psi should i get from each cylinder for a stock rb20det?

[bmadd2402]

it will be cold, so it won't be accurate. what to look for will be equality across the cylinders. more than 10 psi between cylinders would be cause to questioion the motor's quality.what the comp test can tell you is if the rings are bad. do a dry test first, and then do a wet test by putting a capful of oil in each cylinder. if the pressure changes significantly, the rings may be bad. the oil wont affect the valve seals or the head gasket. but beware, they could put the oil in before they do the test, and then you wont be able to tell. From what I've heard, though, venus is pretty good about taking care of things if there is a problem. if you can get them to do a leakdown test, that might be a little more accurate. a new head gasket and new valve seals are easy with the engine on a stand. but if it is the rings, you are looking at a full rebuild. Good luck!!!

[driftmyke]

any numbers?

[bumblebtuna]

i'm gonna say a new rb should be 174ish..

so good would be 150-160?

with oil it should read higher thoughsomeone correct me here if i'm wrong