Was timing chain and camshaft replacment now OH NO!

Question

I posted a few days ago about the timing chain and camshaft on our 68 Coupe and thanks for the replies. Tore into it yesterday and decided to replace the oil pump after finding several missing teeth on the timing gear the rear main that has been leaking so I figured what the hell might as well. When I removed the rear cap, whew it stunk. The race has some copper showing through, so it's off to the machine shop. Should have a strong motor now, does anyone know what compression on a 289 should be at 5000' above sea level?

Thanks, Chris

68 KR Fastback
68 Coupe

Jim Warman · Accepted Answer

Static compression pressures can be misleading.... cylinder seal, valve timing, starter rpm.... too many things can gang up and render the numbers near meaningless. Closest I can suggest would be to expect 125 to 160 psi but look for even more than anything. A leak test is a little more definitive but takes longer to perform. If all you're after with the compression test is a baseline, I woud suggest breaking the cam in properly (change the oil and filter after the break in) before you do the compression test and don't forget to hold the throttle at WOT when checking the compression.

HTH Jim Warman snipped-for-privacy@telusplanet.net

Was timing chain and camshaft replacment now OH NO!

Join the Discussion

Didn't find your answer?