Please Figure this one out!?!
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Teching In
Joined: Sep 2008
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Please Figure this one out!?! Ok we did a compression test on my vette after heads and cam install. All compression is good, until the car warms up. #1 piston goes from good compression to 0 compression. when the car cools down again there is good compression. the only thing i can think of is maybe a crack in the piston that expands when the car gets hot? or am i way off? Please help
did you have a valve job don on the heads? if so maybe the machinist forgot to grind alittle off of the stem of the valve to make it the correct legnth agiain. so when it warms up the valve is open.
If you have a typical compression gauge the take the schrader valve out of it so you can use compressed air to find the problem. Get the car warmed up so that the cylinder goes dead. Remove the valve cover and remove int and exh rockers to that cylinder. Install compression gauge hose to cylinder and shoot compressed air into it. If air blows into the intake,int valve problem. If air blows in the exh,exh valve problem. If you have ring(piston)problems then the air will escape into the crankcase. My theory is your having problems w/ the valve train. Make sure the pushrod length is correct.
