Stock Crank Journals

[49-blues]

Are the stock crank rod and main journals considered wide or narrow and would wide be better?

 

[Ormand]

The rod journals are narrow. In order to make the engine "even fire", the journals had to be made narrower, and bigger in diameter, so the "L over D" got worse. Main journals, I think, are about average, neither wide nor narrow. It is possible to use wider bearing shells in the rods, by cutting down shells from other engines. That gives more wear surface, and more area to support the load, so less pressure, for better wear. Wide journals take more oil pressure, and require the journals to be straighter and rounder, so it's kind of a trade off.