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Location: San Antonio, TX
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PPI Compression and LeakDown Results - '79 930
I had a PPI done on a 1979 930 I'm considering buying which shows 21K miles.
Compression came back at 135 for all six cylinders and 110/110 for all six. I thought results like this were impossible. When I asked the mechanic, he said it was uncommon, but that he does see it occasionally. Any thoughts? Thanks!!! |
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06-28-2004, 12:13 PM
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also... I searched for what the numbers should be and came back with nada...
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06-28-2004, 12:13 PM
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Friend of Warren
Join Date: Oct 2000
Location: Lincoln, NE
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Well 135 in all 6 cylinders for compression is good, but I don't understand the 110/110 for a leakdown figure. Normally it is expressed in percentages. Anything less than 5% leakdown is good. Is he trying to say the leakdown is 0%? If so, then I question the accuracy of the test. Every cylinder will have some leakdown as no cylinder is air tight!
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Kurt V No more Porsches, but a revolving number of motorcycles. |
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06-28-2004, 12:16 PM
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The "110 over 110" is what I was told over the phone. I THINK he was telling me 0%. I'll find out for sure this afternoon when I go back to pick up the report.
Thanks. |
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06-28-2004, 12:24 PM
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Not Quite Banned
Join Date: Dec 1999
Location: Ft. Lauderdale
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Even an engine that had vitually no miles will show some leak. I agree with Kurt that it should be between 1 and 5%. Don't be afraid to ask for a re-test!!!
Good luck,
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Thomas Owen 1972 911T 1972 911S Last edited by Thomas Owen; 06-29-2004 at 10:42 AM.. |
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06-28-2004, 01:23 PM
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Hey skip- If you are looking in Dallas, check out this one:
Also I've done my own leak down tests, and with 100 PSI on a 3.2L engine I got close to 0% leakdown, (less than 1 psi drop). I was surprised. This was with an engine that clamed to have only 15K miles on it.
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Paul 2001 CLK55 AMG, 1987 911 Turbo Look, 1997 Viper GTS. |
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06-28-2004, 01:44 PM
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Quote:
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06-28-2004, 03:45 PM
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Location: MA USA
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When I bought my 930 motor, I did a leakdown. I got 1% to 2.5%. Most were 1.5%
Dean
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Dean 911 SC turbo, 3.0L 930 motor, G50, 930 brakes, DTA EFI, 352 RWHP DynoDynamic dyno, |
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06-28-2004, 06:10 PM
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I had the engine rebuilt on my 89 930 when I got it (broken rings). I did a break-in drive of about 1000 miles up and down hills, full throttle then engine braking, etc. When I took it in for the 1500 mile service, I had the mechanic do a leakdown. He said he got 0% leakdown on all 6 cylinders (the needle just moved off the peg on the gages but didn't show on the scale). I didn't believe it at first but I've heard similar stories since then.
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Phil 89 930 Slate Grey/Black K27 B+B 1 Bar shaved gutters backdated to opening vent windows |
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06-29-2004, 09:50 AM
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Well, the report shows all cylinders at 135 compression. None leaked, except cylinder #2, which dropped from 110# to 100#.
Thanks to all for the input. - Skip |
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06-29-2004, 10:29 AM
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Wow. How much is the car, if you don't mind my asking?
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Beethoven '88 911 Coupe |
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06-29-2004, 10:46 AM
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Beethoven- All the dirty details here
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06-29-2004, 12:33 PM
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