Totall wild compression?

[MrK]

As y'all who read my intro know, I have a somewhat modified engine (304 cam, forged high-comp pistons, springs, etc). What is the correct way to measure compression? Is it after 4 cycles or 6? Cuz after 6 cycles each of my cylinders is giving a reading of about 210(!!!) PSI + or - 2 PSI. How come my engine hasn't blown up yet? LOL

Comments, corrections (flames?) anyone?

Cheers

[SpecM]

-That is very, very high. I have about 170-175 on a bone-stock super-eta.
-I beleive you should measure peak pressure, so 5 or 6 cycles sounds right.

[Brew]

Longer duration and higher lift cams effect compression readings, so comparing them to stock specifications is pointless. As long as your timing is correct, and the compression is close across the board, I wouldn't worry about it.

[Jordan]

I'm all 210PSI +-5PSI as well.

[Tony]

Same here 210 psi, 10.5.to 1 comp pistons 2.7L

[StereoInstaller1]

Kamal, what I was taught as a wee lad was to crank the engine over about 20 seconds with the throttle fully opened to check compression.

Considering the overlap of your cam, 210 does not suprise me a bit, nor does the rough idle.

Liquid-filled motor mounts would last about 3 minuites under that engine, BTW.

Luke

[MrK]

Alright so everything is more or less normal then :)

I'll promptly forget about liquid filled mounts now.... thx for the heads-up.

God knows a 16-year-old car has enough problems of its own, no need to add more by replacing simple parts with more complex ones that can break more easily right ;)