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Registered
Join Date: Feb 2001
Location: idaho springs, co
Posts: 132
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Crankcase pressure
My crankcase is pressurizing and I can't figure out how/why it is. Leakdown is under 3% all around, new oil pump and housing, motor has 2500 miles on it. I just don't get it. It pushes oil out from every available spot, main, tube seals. Any ideas where this can come from???
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11-04-2001, 10:30 AM
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Registered
Join Date: Feb 2001
Location: Aircooled Heaven
Posts: 1,054
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Did you do that leakdown test with the engine at operating temp? Alot happens when things expand.
What cylinders did you use, we have seen some BIG problems with cylinders lately. |
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11-04-2001, 11:46 AM
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Registered
Join Date: Dec 1969
Location: chula vista ca usa
Posts: 5,712
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Pressure in the crankcase comes from ring blow-by and is compounded by the way the pistons move in and out in the cylinders. A stock motor should have a PCV valve venting to the intake plenum. Should be cleaned at least yearly. A modified motor with carbs, big bore, cam, etc will need vents on the valve covers and the crankcase (at least 5/8 inch ID) connecting to a large catch tank with a filter to trap the oil and let vapors out. You can also install a dry sump system with three stage oil pump that will draw a vacuum in the crankcase, but that is biiiiig bucks. You did not mention what type of engine you had? Good luck.
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11-04-2001, 03:59 PM
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