engine compression
Thread Starter
Heel & Toe
Joined: Mar 2008
Posts: 19
Likes: 0
engine compression
This is probably a stupid question, but you never know until you ask. My 79 vette has a 72 vette or truck 454 engine according to the stamped block code. It is not original and the motor has been modified. Now the question, is there anyway to guess or estimate the compression ratio without doing a teardown? if the bore and stroke are still original,,What should it read on a compression test?
Melting Slicks
Joined: Mar 2008
Posts: 2,989
Likes: 198
From: Meriden CT
You need the size of the combustion chambers before you can make a guess. The "right" way takes alot of things into account, deck height,piston top shape, valve reliefs, chamfer, gasket thickness, chamber volume, etc. Good luck.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
You need LOTS of info for the proper static compression ratio, and you have to have the heads off at the very least to figure out more of it.
Burning Brakes
Joined: Feb 2000
Posts: 1,246
Likes: 1
Get the cyl head casting number and the block suffix, that will give you a good idea what's in there most likely.
Comp. test does not relate to static compression (which is just a number and has little to do with the actual cylinder pressures the engine sees)
Comp. test does not relate to static compression (which is just a number and has little to do with the actual cylinder pressures the engine sees)
