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Registered
Join Date: May 2003
Location: Paris
Posts: 135
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technical advice about 2.2 T compression test
Hi gurus... I do not have comparisons tests and I don't how many bars (Psi) should have an engine with good health (1 bar = 14.504 Psi). Nominal CR for a 2.2 T is 8.6
Any advice about my test is welcome ![]() |
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Join Date: Feb 2006
Location: Oahu
Posts: 2,303
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I've always hear that 17 was the comp. ratio factor. So in your case: 17 X 8.6= 146.2 lbs., or 10.07 bars. Hope that helps.
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Jon |
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Join Date: May 2003
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So it feels that my piston rings are very tired ...
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Join Date: Feb 2006
Location: Oahu
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I think without a leakdown test, you don't know for sure that rings are the problem, and I wish I was positive about the factor of 17. There are plenty of really sharp folks here. Maybe one of them will chime in.
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Jon |
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any other advice ?
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Registered
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Your compression numbers are pretty even, and that is good, "no cow on the ice" as we say in Sweden
![]() To see if your rings are worn or valves don't seal as good as they should you will need a leak down test.
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Magnus 911 Silver Targa -77, 3.2 -84 with custom ITBs and EFI. 911T Coupe -69, 3.6, G50, "RSR", track day. 924 -79 Rat Rod EFI/Turbo 375whp@1.85bar. 931 -79 under total restoration. |
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Join Date: Dec 2007
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I just looked it up and you are correct. 1 Bar =14.5 PSI. If that Holds true then the PSI numbers seem to be on the low side. I found my 2.2 in a junk yard and did a cold compression test and all of them were in the 135-145 range. Before you hit the panic button do yourself a favor and get a different tester and measure again. Remember that the motor needs to be warmed up first and if it is Carburated the throtles need to be fully open while doing the test. Dont forget to keep turning the motor over until the needle stops
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and remove all spark plugs to make it turn over more easily, otherwise it can drain the battery so it turns slower on the last cylinder than on the first.
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Magnus 911 Silver Targa -77, 3.2 -84 with custom ITBs and EFI. 911T Coupe -69, 3.6, G50, "RSR", track day. 924 -79 Rat Rod EFI/Turbo 375whp@1.85bar. 931 -79 under total restoration. |
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Join Date: Jun 2001
Location: Sweden
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1. Warm up the engine
2. Do a test with plugs out and throttle wide open 3. If C/R is even (+-5%) on all cylinders, you are probably OK 4. Squirt some oil into cylinders and redo the test. Compare with "dry" test.
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Thank you for your time, |
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My 2,2 - Weber carbed (unknown history) tested 140, 145, 135, 140, 145, 140 at Vision Motorsports.
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Gary 71 911T Miss Demeanor / 2013 Audi Q5 Hundeführer / 1995 993 Miss Adventure |
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