M20B25 Main Bearing Oil Clearance

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b12rlw
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Post Thu Feb 09, 2012 7:49 pm

Hey folks, Ive just bought a set of mains for an aplication as follows..

Crank Journals - 59.97mm
Main Brg OD (ie. block id) - 65.04mm
Brg Thickness - 2.498mm

my calcs for a lubrication clearance are as follows..

gap between block and crank -> 65.04 - 59.97 =5.07

Brg thickness (accounting for both shells) -> 2*2.498 = 4.996

Subtraction of the two resulting in oil film clearance ->
5.07-4.996 = .074mm

my question is.... Is this a large enough clearance??
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Brianmoooore
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Post Thu Feb 09, 2012 8:32 pm

Look for the M3 rebuild by x-works. I believe he goes into this in some detail in his build of the engine.