Originally Posted By DrCharles
Originally Posted By JohnRR
Side clearance is a clearance just like bearing clearance, the wider the gap ....


Yes, and so is header clearance. Not the point. Please go back and read my post more carefully ... where does the oil (that's escaping from those side clearances) come from? That's right, it's already been through the tightest restriction, the bearing clearance. It is NOT an "independent" leak stealing oil directly from the pressurized galleries and dripping it back to the pan!

So the effect of a wide side clearance is very small (if not absolutely negligible) compared to bearing clearance. As many guys who have put Chevy-width rods on Mopar-width cranks have discovered, with plenty of oil pressure.

Meanwhile, go on believing as you please. No point in trying to teach something to people who already "know".



Correct. The governing pressure drop is going to be the tightest (smallest area) flow in the system. Once the oil has squeezed through the bearing faces, it is basically open to the internal of the engine. If the side clearance was zero, there would be no flow but you may not necessarily see infinite pressure because of oil flowing through other parts of the engine (the next largest open areas). Once the side clearance is equal to the bearing clearance or greater, it no longer has a significant impact on pressure drop.


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