Small block compression?

Question

I am considering buying an L81 350cu engine 'cut out' from a 1981 Corvette.The seller sent me pics. of the compression test. He's 300 miles away and I wondered if anyone can advise me if the compressions are within an acceptable range? I would like to fit this engine without tearing it down first!
The compression range is between just over 8 to 12 bar over the 8 cylinders. It it worth the trip?

Answer 1

I not up to date on the bar readings, but in PSI you want to see around 150 psi very min. to 190 psi (stock engine will not read that high though). Common is 160 psi to 170 psi



You don't want any more that 10% max diff in pressure between the lowest reading cyl., and highest reading cyl.

Answer 2

on a compression try you're able to see effects interior the variety of a hundred and fifty-a hundred seventy five psi with the utmost and lowest nevertheless interior of 10% of one yet another. something under a hundred and forty will contemporary a susceptible engine and an illustration of a failing block. optimistic you're able to have an engine run with a hundred psi, even though it does no longer paintings properly under a load. I somewhat have a vehicle with 243000 miles that still develops approximately a hundred sixty five psi in each cylinder elementary. minimum e book spec is 143. and that's a compact vehicle from 1990.

Answer 3

pass on it. if i remember a bar of pressure is like 12 or 14 psi. 4 bar would be at least 48 psi or so....way too big of a spread. buy it to rebuild or pass on the engine entirely.

Answer 4

rather than looking for a specific pressure.....make sure all cylinder,s are even.....within a 10% range of one another.....on average look for aprox......60 to 80 lbs. per square inch...per cylinder.....anything lower than 50 is questional.

Answer 5

compression tets should be in cylinder pressures... all cylinders should be within 10% of each other no matter what .