 Compression ratio, Whats the max CP differance |
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| DavidSweden |
 Jan 19 2021, 03:47 PM
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#1
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Member  Group: Members Posts: 479 Joined: 8-June 14 From: Sweden Member No.: 17,452 Region Association: Scandinavia  |
Hello,
What is the maximum allowable compression ratio difference between cylinders? 2056 motor AA big bore Thanks in advance |
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| rfinegan |
Jan 20 2021, 11:15 AM
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#2
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Senior Member Group: Members Posts: 973 Joined: 8-February 13 From: NC Member No.: 15,499 Region Association: MidAtlantic Region 
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that is pretty low compression ratios
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| Dave_Darling |
Jan 21 2021, 04:53 PM
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#3
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914 Idiot Group: Members Posts: 14,986 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California
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QUOTE(rfinegan @ Jan 20 2021, 09:15 AM)  that is pretty low compression ratios Not for a 914. Stock compression ratio for the US-spec 2.0 motor is 7.6:1 . I wouldn't go over 8.5:1 in an otherwise-stock motor. You want the CR difference from cylinder to cylinder to be as small as you can get it. More even means less overall wear and generally better power and more smoothness. --DD |
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| stownsen914 |
Jan 22 2021, 11:35 AM
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#4
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Senior Member Group: Members Posts: 913 Joined: 3-October 06 From: Ossining, NY Member No.: 6,985 Region Association: None |
If I read your post right, wouldn't the fix be to cut the head for cyl 1 & 2 so it matches the other one, and get the volume both at 57cc?
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Posts in this topic
DavidSweden Compression ratio Jan 19 2021, 03:47 PM
rfinegan I believe under 50 to 60 psi will have problems an... Jan 19 2021, 03:57 PM Jake Raby What values are you seeing? Are you performing ng ... Jan 19 2021, 09:40 PM DavidSweden I am installing some new heads because of damage t... Jan 20 2021, 10:39 AM rfinegan what does the work out as far as % error on your C... Jan 20 2021, 11:14 AM
Jake Raby I thought you were trying to get a value for a com... Jan 20 2021, 03:00 PM DavidSweden
I thought you were trying to get a value for a co... Jan 20 2021, 03:20 PM
rfinegan I have read a lot of the AA cylinders have to be t... Jan 20 2021, 03:37 PM |
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