compression #'ss
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Honda-Tech Member
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From: HOT AS HELL, az, usa
compression #'ss
just a quick question
what should a 84mm GSR with 9.5:1 cp pistons be at
i got about 150psi accross all very close to each other
that seems low to me....i have heard from some people that is good......ok....bad....some even said i should be gettin like 190psi
what's the deal
what should a 84mm GSR with 9.5:1 cp pistons be at
i got about 150psi accross all very close to each other
that seems low to me....i have heard from some people that is good......ok....bad....some even said i should be gettin like 190psi
what's the deal
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Joined: Oct 2004
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From: morgantown, wv, usa
Re: compression #'ss (lucidvtec)
this is from jeff evans dyno tune check list
Compression test results should be as follows:
8:1-8.5:1 compression: 150-170 psi per cylinder
8.5:1~9.5:1 compression: 170-210 psi per cylinder
9.5:1~11:1 compression: 210-275 psi per cylinder
11:1+ compression: 250+ per cylinder (highly depends on cams being used)
DO NOT have more than 20psi variance between cylinders. It is not ok to come for an appointment where there are 3 cylinders that have good compression and one that doesn’t. The 3 good don’t make up for the one bad.
Compression test results should be as follows:
8:1-8.5:1 compression: 150-170 psi per cylinder
8.5:1~9.5:1 compression: 170-210 psi per cylinder
9.5:1~11:1 compression: 210-275 psi per cylinder
11:1+ compression: 250+ per cylinder (highly depends on cams being used)
DO NOT have more than 20psi variance between cylinders. It is not ok to come for an appointment where there are 3 cylinders that have good compression and one that doesn’t. The 3 good don’t make up for the one bad.
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From: Watertown, CT, USA
That sounds low to me but I think Jeff Evans is a little optimistic with his numbers. Stock D16's with some wear on them net like 170-180 and they're 9.2:1. And Type R's definitely don't pull anywhere near 250 psi, even new. I say if the leakdown is good and it doesn't smoke don't worry about it. My 8:1 Vitaras pull 120-125 and it runs fine.
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Joined: Aug 2001
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From: Vancouver, BC, Canada
Re: (nonvtecD)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nonvtecD »</TD></TR><TR><TD CLASS="quote">That sounds low to me but I think Jeff Evans is a little optimistic with his numbers. Stock D16's with some wear on them net like 170-180 and they're 9.2:1. And Type R's definitely don't pull anywhere near 250 psi, even new. I say if the leakdown is good and it doesn't smoke don't worry about it. My 8:1 Vitaras pull 120-125 and it runs fine.</TD></TR></TABLE>
it also depends if you have the TB open or not
did a compression test on my y8 a little while ago
operating temps, WOT, 210across all 4 cyclinders
stock y8 cr is 9.6:1
warm usdm b16, WOT, 230across all 4 cyclinders
i think Jeff Evans #'s are pretty close
it also depends if you have the TB open or not
did a compression test on my y8 a little while ago
operating temps, WOT, 210across all 4 cyclinders
stock y8 cr is 9.6:1
warm usdm b16, WOT, 230across all 4 cyclinders
i think Jeff Evans #'s are pretty close
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Joined: Mar 2004
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From: champaign, il, usa
Re: compression #'ss (lucidvtec)
did you make sure you did WOT when you did the compression test. on my d16, when i forgot to do WOT, i got 130psi across the board. this is 9:1 compression pistons. then a few days later i did it again with WOT and i got 180psi across the board. i did this test a few weeks ago and open throttle does make a huge difference.
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