Originally Posted by bugeyes
I recently started a thread based on balancing of subaru crankshafts. The fact is the subaru crank cannot accomodate counterweights large enough to cancel out the weight of the rod/piston. Therefore the crankshaft is considered to be a "coupled" type crank which relies on the two adjacent journal loads to cancel each other out. What I am saying is the 2 front cylinders cancel each other out due to them being 180 degrees apart on the crank. This puts extra load on the main journal between them.
What I am getting to here is if you fit heavy rods and heavy pistons you are increasing the load through the crank which would increase any amount of twisting and hence increase the chance of oil failure (if this theory is correct??).
making a good reason to choose piston size (for CFM: RPM differences between smaller and larger displacement) and titanium rods a good call