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bdonally bdonally is offline
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Join Date: Dec 2001
Location: Off grid in Eastern ONtario
Posts: 201
Strange compression and leakdown results

Posted this on the general BBS but this is probably a better place.

Just finished checking compression and leakdown.
Cyl 1,2,3: comp ~115, leakdown ~40%, lots of air through oil tank
Cyl 4,5,6: comp ~155, leakdown 3-5%
The testing was done cold, and the results are repeatable. I can do a hot test, but the left bank is so bad that I cannot imagine it getting a whole bunch better hot.
I have been chasing a high temp problem, and eventually noticed a LOT of blowby from the oil tank.
Car has 140,000KM, top-notch rebuild at 75000km (mainly durabilitystuff for possible racing) and about 2o% of the mileage since the rebuild has been at DE events. During the rebuild the inlet manifold was ported, an Autothority maf and chip installed, along with a Al flywheel. Also valves, guides, bolts, etc.

Before I bite the bullet and pull it out, any ideas why the tests would be so lousy yet uniform on one bank, and pretty good on the other?
Bob D.
'84 Carrera - MAF, Wong chip, RSR flywheel, ER bushings and other bits, CTR fiberglass F/R bumpers, 7/9 Fuchs, 22/27 TB, 22/21 SB, bunch of other little stuff
'69 Lotus 7 Series 3; '74 Fiat X1/9
'14 X5 diesel
Old 09-05-2005, 02:06 PM
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