Quote:
Originally Posted by Jerry Clayton
Bearing clearance determines oil flow UNLESS side clearance is inadequte
Lots of newer very high level engines use huge side clearance however they control rod placement by centering at the wrist pin---similar to a 2 cycle with top guided rods |
In agreement with wht you stated, but to elaborate, side clearance would have to be very tight to be inadequate when you figure you have a
total area of clearance of just over .004"sq. around a 2.200 journal with .0025 clearance and a .5" wide bearing. No more
oil is going to pass through that bearing and come off that crank than that .0043" sq. of area will allow. Using the piston pin boss to locate and guide the rod instead of the crank journals, as mentioned before, allows narrower rods and bearings, less friction, less heat, less recip. mass, etc.
