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View Full Version : COMMPRESSION TEST HELP



rickylsi
04-25-2007, 05:12 PM
I just did a compression check on my jdm zc sohc vtec and I dont know how to see if its good or bad. Does anyone know a website or what the psi or kPa is suppose to be. Thanks

TheGodfather
04-25-2007, 06:02 PM
I believe it is supposed to be 7psi. At least that is max the stock tie rods are supposed to handle, so I'm guessing it would be the number you are looking for.

jmmx258
04-25-2007, 06:10 PM
I believe it is supposed to be 7psi. At least that is max the stock tie rods are supposed to handle, so I'm guessing it would be the number you are looking for.

I hope to god your kidding.


Shoot for around 140 -+5

At 130 its safe but about due for a rebuild. If its more or less than 5lbs from each hole its time for something as well. Rings, valves, pistons, the likes. Have it all checked out.

When checking though, crank it for about 6 rotations, with the throttle to the floor. Make sure you have hall the plugs unhooked, or u'll be buying a new comp. tester lol

rickylsi
04-25-2007, 06:53 PM
I unhooked my msd so no fire and pressed the gas to the floor each time and turned 4-5 turns on the crank and my 1 is 190, 2 is 185, 3 is 180, 4 is 180 goin left to right lookin at the motor. IS THAT OK.......

pitbull325
04-25-2007, 08:25 PM
Yeah, that's good compression. They say there shouldn't be more than 15% variance from the lowest to the highest. To keep the math simple, multiply the lowest by 1.15 and if it's still lower than the highest, you're engine isn't too healthy.

jmmx258
04-26-2007, 03:27 PM
Different motor than what I was thinking. I believe it was like 140 in my D16 lol. My bad! Yeah that sounds fine though.

I know my B16 i'm pullin 180 a hole

speedminded
04-26-2007, 04:04 PM
The main thing is how do they compare between each cylinder? Then go from there...