ORIGINAL: bkdavy
As for Ball Bearing vs Bushing, now you're talking about the crankshaft support. A Bushing engine is lighter and cheaper to produce, but the bushing is by nature a higher friction part. A Ball Bearing requires more weight, but significantly reduces the friction lost in the crank. Consequently, equivalent size Ball Bearing engines (BB) will be more powerful than bushing engines, but you will eventually have to replace bearings.
Brad
There isn't even close to enough extra friction in a bushing to account for the horsepower difference. Ball bearing engines make more power for a lot of other reasons. For example, compare venturi sizes of a bushing engine to a ball bearing engine of approximately the same size.
