hughesboysvaliant
Well-Known Member
Hey guys , got a question. I was checking the old car out the other day and tried the paper to the tailpipe trick to check for a burnt valve and sure enough the paper would suck up to the pipe and out very quickly. Well I just knew I had a burnt valve or two on the exhaust. It thought I would go ahead and check the intake valves with a vacuum gauge and they all looked good about 14" - 14.5" vacuum with very little slow needle movement in that range. So I moved on to the leak down test . Cranked each cylinder to TDC and set the regulator to 100 psi and went threw the cylinders the worst one was 89 psi the rest was between 90 to 92 psi. So 8 to 10% leak and one with 11 %. Check the tail pipes with my ear every cylinder heard nothing, intake nothing, crankcase was where I heard any air , normal at the % leak I saw. Scratching my head now. So I think cam reversion maybe. The motor is LA 360 with a comp XE268 cam and lifters. The cam is 234 @ 50, 110 LSA, 477 -480 lift with 54 degrees of overlap. Installed straight up dot to dot no advance. The heads are 360 cast iron non smog that has 2.02 1.60 SS valves, shaved 60 thousand mopar performance valve springs shorter push rods and some port work with gasket matching. They run into TTI step headers 1 5/8 to 1 3/4. My question is what do you think is there a problem. Could the springs be weak, could a valve be sticking or would you see that at idle with that cam ?