Monday, April 14, 2008 - 08:55 am, by: Shaun Chiew(Senk9)
You're thinking of compression ratio, like they list on spec sheets ..
Compression testers give a readout in PSI for static compression ... Go to any workshop / wrecker and they'll test individual cylinders in this way ...
Monday, April 14, 2008 - 08:56 am, by: Luke Burt(Burt)
Not when doing a compression test
Compression test consists of your tester, then you unscrew a spark plug, and crank the motor(after removing fuel pump relay/fuse as you dont want any fuel in the cylinders, or the motor to fire up..), it will give you a reading for compression, the tester sits tight in your spark plug hole and as the piston comes up it will give you a compression reading in psi.
As stated above 160-180 is about ideal but it's more important to have consistancy accross the chambers, ie 174, 173, 178, 169, 150, 170 means you probably haved rings on piston 5.