Thread: airhead noob
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Old 10-14-2012, 06:00 PM   #38
DoktorT
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Joined: Apr 2009
Location: Chewelah, WA
Oddometer: 1,146
High spec comp should be 145 to 150. At that level, leak down will be around 2 or 3%

Leakdown at 110lbs comp will be some 80%-90%. Any less than 90% is rebuild time.

You simply will not see 50% leakdown at 140lbs. Could be you had a good test for comp then a bit of a piece of crud ended up fouling a valve. Run the motor to full temp then test again. Ane the whole idea behind a leak down test is to determine where the loss is occuring, valves int or exh or rings or head gasket or a combination.

I doubt you would have any potential to start the motor at 50% leak down, and then if it did would run like crap and certainly would not idle.

You got some bad data due to procedure or instruments.
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