Dollar bill test....

[Cliff8928]

I imagine if you have the -13° exhaust cam, this will be amplified even more!


Cliff Scott
89 BerettaGT
89 Volvo740

[pocket-rocket]

I initially thought bad exhaust valve. Reason being when the valve closes, but doesn't seal, a vacuum would be created from the piston making its way to BDC. The 91 has the -13* cam timing done, I should try the dollar bill test for shits and giggles sometime. I know the valves are also good because we cleaned them when the heads were ported and polished and they were fine. Also we lapped them when we put them back in.