Quote:
Originally Posted by boosted79
I would not assemble an engine with 4 tenths mains that runs 20-50. 2 is better than 2.8 on the mains for the street. 2.2 is better than 3.2 on the rods. Race engine running high revs and straight 50 the larger is good. Rod big ends don't stay round at high rpms so the add'l clearance accomodates that. Tight clearances require perfect geometry on the parts involved along with thin oil. The old standby of 1 thou per inch of journal for the street has stood the test of time.
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Follow up question...
With Porsche we don't have the luxury of multiple over and undersized bearings...
So what is an acceptable bearing clearance spread? .0025 on all bearings would be great, but unlikely...
So, what do you do if some are .0022 and some .0025 and some .0027?
Seems most folks on here use plastigauge, which in no way would show those differences. Others use lower priced bore gauges, which only measure to .0005. So, most folks simply don't realize a difference exists.
My indicator goes to .0001... And it's incredibly repeatable.
Am I over thinking this??? With a Chevy you can mix and match 1/2 shells and buy special thicknesses. Not so much with Porsche...
Live with it I assume?