454 Compression Testing? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

savatreatabvr · 10-15-2012, 02:32 PM

I did a compression test on my mid 70's 454, I would bump the engine to get one compression stroke and I got around 90 psi per cylinder but if I turn the engine over to get 3 or 4 compression strokes they all levels off around 100 -110 psi per cylinder! So my first question is, is the 90 psi the true compression reading? Second question is, if my valves are out of adjustment will I still get the same compression readings?

10-15-2012, 02:32 PM	#1
savatreatabvr Registered User Join Date: Oct 2011 Location: phoenix, az Posts: 508	454 Compression Testing? I did a compression test on my mid 70's 454, I would bump the engine to get one compression stroke and I got around 90 psi per cylinder but if I turn the engine over to get 3 or 4 compression strokes they all levels off around 100 -110 psi per cylinder! So my first question is, is the 90 psi the true compression reading? Second question is, if my valves are out of adjustment will I still get the same compression readings?



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