naru

In theory yes,in practice no.Have you ever compression tested a subaru engine hot and cold? VERY little difference. The question was whether different cams could affect compression gauge readings. The answer is yes. To see how much, a cold test should be compared to a cold one and hot to hot w/the cams as the only variable. "no pressure condition" Huh? Whazat? A weak battery will affect results hot or cold, in or out of the car.As long as you have consistent cranking rpm you`re OK.FSM suggests 250-350 rpm w/corresponding pressure variations.

Sure, but they say it better: http://e30m3performance.com/myths/more_myths1/comp_ratio/comp_ratio2.htm http://www.kennedysdynotune.com/Dynamic%20Compression%20Tech.htm http://webpages.charter.net/darrell1/dynamiccr.htm

30 psi? YIKES! How did it run? You guys should read this Pontaic based discussion of cam selection/installation and compression gauge readings: http://www.thepontiactransampage.com/engineblueprint.html

Sure you can test compression on a stand as long as you use the starter. If you have installed increased duration camshafts w/no other mods,you will have a lower gauge reading because of the decreased dynamic compression ratio. Significantly increased duration requires increasing the static compression ratio to maintain a reasonable dynamic ratio and compression gauge reading for good low RPM operation.