Gentlemen:

Let's take a look close to home, in fact in our driveways. In your car you will find a crankshaft without even one roller or ball bearing on it. This is not merely because plain bearings are cheaper, but the last production cars with ball and roller bearing cranks (Porsche/Hirth) had more problems with the cranks than any other part of the engine.

I flew U/C speed years ago, and sad to say, the plain bearing engines could be made a lot faster than ball bearing engines of the same size. K&B and Fox killed McCoy and Dooling. Even Cox, when they ruled in 1/2A, made a "Space Hopper" with a BB crank. The plain bearing version blew it away.

Problem is centrifugal force, this throws the balls against the races, at higher speeds the balls will push through the oil film and run unlubricated against the races, giving high wear. And even at lower speed the balls have to push their way through the oil film, whch takes power, whereas the plain bearing has a constant "Tear" in the oil film, leading to less drag on the crank.

In modern speed engines, the loads are such that, combined with ceramic bearings, the BB advantages outweigh their disadvantages, but that is CERAMIC bearings. Just put a set in a Saito, only cost four times what ordinary bearings cost. And that was close to the price of an OS 46 FP.

What this is leading to, is that a plain bearing 46 is a much better engine for a casual flyer than a BB cranked engine. Properly cared for it will outlast three or four sets of bearings in the other engine, and if not properly cared for will still outlast the BB engine treated the same way.

Key words are "Treated the same way." The plain bearing engine will stand up to much more mistreatment than the BB engine. Do you always run the fuel out after a day's flying? Are you religious about after run oil? If you don't do these things the plain bearing engine will live through it, you'll probably never see any difference in it from the lack. The ball bearing engine will become junk quickly.

First engine? Whatever brand, go for a plain bearing crank.

Plain bearing or ball, Twin engines haul.

Bill.