http://theoldmotor.com/?p=176239
http://theoldmotor.com/?p=176554
keep in mind in a properly built engine,with proper clearances,
the crank bearing surfaces ride suspended on a pressurized oil film,
so no metal surface ever touch once oil pressure reaches 25-30 psi,
thus I don,t see this as potentially being a huge advantage ,
especially once the huge cost increase , and the need for both greater oil flow rates ,
for roller bearings and greater piston to head quench clearance is considered.
roller crank bearings were not un-common in motor cycles,
but remember roller bearings don,t like to operate at,
much under 3000 rpm for very long under load
http://theoldmotor.com/?p=176554
keep in mind in a properly built engine,with proper clearances,
the crank bearing surfaces ride suspended on a pressurized oil film,
so no metal surface ever touch once oil pressure reaches 25-30 psi,
thus I don,t see this as potentially being a huge advantage ,
especially once the huge cost increase , and the need for both greater oil flow rates ,
for roller bearings and greater piston to head quench clearance is considered.
roller crank bearings were not un-common in motor cycles,
but remember roller bearings don,t like to operate at,
much under 3000 rpm for very long under load
