Compression test result
Thread Starter
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Joined: Dec 2003
Posts: 2,315
From: NY...what a bad place for a nice car
Compression test result
I got 150psi on all cylinders.
355 11 to 1 comp.
236/244 598 614 if it matters.
Dry test.
Seem normal? I hear it's not about the number it's about consistency.
Also engine was cold, sat for a few days 60 degrees out. I did test one cylinder a few days ago when it was 85 degrees out it was at 180 same cylinder was 150 today but with a different tester.
355 11 to 1 comp.
236/244 598 614 if it matters.
Dry test.
Seem normal? I hear it's not about the number it's about consistency.
Also engine was cold, sat for a few days 60 degrees out. I did test one cylinder a few days ago when it was 85 degrees out it was at 180 same cylinder was 150 today but with a different tester.
Thread Starter
Registered User
Joined: Dec 2003
Posts: 2,315
From: NY...what a bad place for a nice car
Re: Compression test result
Compression test should be done with engine warm, nearly operating temp. But who can get their arms and hands near the exhaust manifolds on a hot engine to remove the spark plugs? And I'm sure you know you need the throttle blades fixed open.
That said good compression pressure for performance should be over 180psi but less than 220psi for pump gas. 150psi is fine for a street engine and should keep you out of detonation.
That said good compression pressure for performance should be over 180psi but less than 220psi for pump gas. 150psi is fine for a street engine and should keep you out of detonation.
reason being is i had no injectors at the time. Was getting them tested so I couldn't run the car.
I bet if the car was warm and lubricated it probably would have been in the 160s 170s.
I could wait to put it back together and try one or two cylinders warm. I wouldn't think id have to do all them since they would probably be the same considering my previous results.
All plugs were out and blades were open
Thread Starter
Registered User
Joined: Dec 2003
Posts: 2,315
From: NY...what a bad place for a nice car
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Joined: Sep 2003
Posts: 1,917
From: Las Vegas
Re: Compression test result
Is it reasonable to assume that because the cylinders were all close in a cold scenario, that you would only have to test one in a hot scenario to get a reasonable idea of where the engine is? Or is heat on the rings enough of a game changer that there could be significant difference?
Thread Starter
Registered User
Joined: Dec 2003
Posts: 2,315
From: NY...what a bad place for a nice car
Re: Compression test result
Is it reasonable to assume that because the cylinders were all close in a cold scenario, that you would only have to test one in a hot scenario to get a reasonable idea of where the engine is? Or is heat on the rings enough of a game changer that there could be significant difference?
Registered User
Joined: Dec 2000
Posts: 1,320
From: Alta Loma, CA
Re: Compression test result
Any thoughts on this? I'm in the same scenario. Looking at my turbo headers, I can't see I'd be able to test any cylinders except for #1 while the car is warm without needing medical attention afterwards. 
Last edited by snorkelface; Oct 22, 2017 at 12:08 PM.