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Registered
Join Date: Feb 2006
Posts: 9
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Leak down and compression results!!!
I received the results this afternoon on an '85 with 40K on a rebuilt top/bottom and trans.
Five cylinders checked out at 100%, #3 was at 98%. Compression test came back at 145, 150, 140, 140, 140, and 145. I know the leak down results are great. How about the compression? Also, are these numbers about right for a 3.2 car with 10:3 pistons? |
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Registered
Join Date: Jun 2004
Location: Rio Rancho, New Mexico
Posts: 1,325
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The numbers don't match.
Gapless rings might get close to 100% on a fresh rebuild. A 40K motor is going to have 5-15% leakdown and be in good condition. Just for the sake of argument let's say the leakdown is close to accurate. The compression readings would be closer to 180 PSI or more. My 2.7 with a fresh top end, did 155-160 PSI at 5,000 ft elevation with 9.5 pistons. Somebody has given you fake numbers.
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DOUG '76 911S 2.7, webers, solex cams, JE pistons, '74 exhaust, 23 & 28 torsion bars, 930 calipers & rotors, Hoosiers on 8's & 9's. '85 911 Carrera, stock, just painted, Orient Red |
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Registered
Join Date: Oct 2003
Location: Bremerton, WA
Posts: 378
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Something seems wrong here, did a porsche shop give you those numbers or?
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1983 911SC 1977 911S "parting out" |
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Registered
Join Date: Jan 2003
Location: Langley,B.C.
Posts: 11,992
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Where do you live? (altitude can play a role) Did they open the throttle when they did the compression check?
Cheers
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Turn3 Autosport- Full Service and Race Prep www.turn3autosport.com 997 S 4.0, Cayman S 3.8, Cayenne Turbo, Macan Turbo, 69 911, Mini R53 JCW , RADICAL SR3 |
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Air Medal or two
Join Date: Jul 2003
Location: cross roads
Posts: 14,079
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Big cam ??
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D troop 3/5 Air Cav,( Bastard CAV) and 162 Assult Helicopter Co- (Vultures) South of Saigon, U Minh Forest, Delta, and all parts in between |
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