ORIGINAL: Rcpilet
The difference between a pain bearing engine and a ball bearing engine:
About 300RPM.
Plain bearing:
bronze ferrite BUSHING to support the crankshaft in the crank case
Ball bearing
steel balls inside a race--pressed into the case--supports the crankshaft
ABC/ABN/ABL:
piston without a ring--chrome sleeve--tapered at the top
Ringed:
piston with a ring--chrome sleeve--straight bore
Good concise stuff
Additionally, ringed engines may have a steel sleeve rather than chromed & some lapped-piston types (Enya, in some examples) have steel cyl liners without significant (or any) taper.