Ludeboye1

Is it normal for a 10:1 motor to show 180 all across the board I know stock compression end up being somewhere between 220-240 I couldn't find this info anywhere. This is a brand new built motor.

s2000Junky

Seems low. My 9.6:1 made 210-220. But there are a handful of variables such as gauges reading different, was the motor warm or cold and was the throttle plate open or closed during cycling. So I wouldn't be overly concerned as long as all the cylinders are reading even.

soulicious

Ludeboye1

Thanks guys the block is brand new not broken in yet but had 1-2 dyno tunes/passes would compression be affected by aftermarket cams?

Colin Shipp

Your pressures will increase when the engine is broken in New motors will rotate slightly slower when cranking. If your new cams have more overlap that will cause a slightly lower reading of your compression test too . Most important is variation or the lack of it
Repeat the test in a 1k miles or so I would expect 20x compression ratio or even very slightly higher on one of these motors

s2000Junky

They are turbo cams, so they should have a lot less overlap. Don't think compression would be effected anyway compared to stock s2k cams.

bruthaboost

My 10:1 motor was around 210 (CP pistons). If you have concerns, do a leakdown test.

LostMarine

my 10.1 was about 180 across the board. depends on the PTW gap. mines built loose to make big BIG HP