Compression test on a 9:1 forged engine - think it's bad!?
03-02-2010, 10:07 AM
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Compression test results on a 9:1 forged engine! Is my engine ok?
Alright guys,
Got back onto my project turbo B16. Its been sat a while feeling sorry for itself, but before getting started I thought I'd check how healthy it is, so done a compression test.
It's a B16 with CP 9:1 pistons.
On another thread in this forum I seen this:
The results I got were: 175 - 170 - 165 - 175
So they are lower than they should be and not the same! What does this mean and where should I go from here guys?
Got back onto my project turbo B16. Its been sat a while feeling sorry for itself, but before getting started I thought I'd check how healthy it is, so done a compression test.
It's a B16 with CP 9:1 pistons.
On another thread in this forum I seen this:
per the evans tuning checklist:
8.5:1~9.5:1 compression: 170-210 psi per cylinder
8.5:1~9.5:1 compression: 170-210 psi per cylinder
The results I got were: 175 - 170 - 165 - 175
So they are lower than they should be and not the same! What does this mean and where should I go from here guys?
Last edited by DreTec; 03-02-2010 at 12:25 PM.
03-02-2010, 10:21 AM
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Re: Compression test on a 9:1 forged engine - think it's bad!?
Well it's hard to say, cos the turbo is shot. Buying a new one when I come over to Florida in April. But the engine is coming out anyway for me to clean it up, and flush the engine bay. So done the test now cos if somethings wrong I could sort it whilst it's out, but didn't wanna have to open up the engine if I could help it.
So the results I got were ok?
So the results I got were ok?
03-02-2010, 12:24 PM
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Re: Compression test on a 9:1 forged engine - think it's bad!?
^^ I'm not questioning how good a 9:1 forged build is... I'm questioning my compression test results. They are low and a not all cylinders results were the same.
Can anyone else confirm that my results are ok or should I be concerned? Thanks.
Can anyone else confirm that my results are ok or should I be concerned? Thanks.
03-02-2010, 12:57 PM
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Re: Compression test on a 9:1 forged engine - think it's bad!?
looks fine to me. as long as they're 20psi within each other its good. how did you do the test?
03-02-2010, 01:02 PM
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Re: Compression test on a 9:1 forged engine - think it's bad!?
Cool! First time I done one to be honest. Figured I done it right. Plugs out, screwed in the comp tester, had a friend turn the engine over until the needle maxed out. The tester was also Snap-On so imagine the results were reliable. That's right yeah?
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03-02-2010, 01:06 PM
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Re: Compression test on a 9:1 forged engine - think it's bad!?
No, literally just turned it over. DOH! I take it this means my results aren't accurate!
03-02-2010, 01:11 PM
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Re: Compression test on a 9:1 forged engine - think it's bad!?
you have to disconnect the injectors. i usually just unplug the fuel pump fuse and run it til it dies. then i do the compression test.
03-02-2010, 01:19 PM
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Re: Compression test on a 9:1 forged engine - think it's bad!?
Ok, thanks alot guys!!
Will do it tomorrow and post my new results. I'm in the UK and it's 11pm so bit late now.
Will do it tomorrow and post my new results. I'm in the UK and it's 11pm so bit late now.
03-03-2010, 09:08 AM
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Re: Compression test on a 9:1 forged engine - think it's bad!?
Thanks for pointing me in the right direction guys, after doing the test PROPERLY I got some great new results: 185 - 180 - 180 - 185
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