Roller bearings for the stationary gears

[vex]

Originally Posted by Cp1

i can give you all the answer you need. roller bearing slow the movement considerably when wet (oiled). this has been tried before with pretty dismal results on piston engines. first problem the strength of the bearing needs to be pretty good as the forces acting on it are extremely high. .

Secondly a roller bearing increases friction causing more heat and wear. this is simply because an oiled journal bearing the two surfaces dont actually touch when moving they are "sliding" on a very thin layer of oil which is also the same way some screw compressor superchargers work. a good hone will provide as good of benefit as a roller bearing without the cost or difficulty. yes it has been done but it is not economical nor is it durable.

F1 cars have used them true but the engine is also designed to last 1-2 races max and all of the fluids are pre-warmed before going in because of tolerances. your motor is nowhere near this and speaking from experience i would not recommend this.

Edit i have been wanting to try boring out the stock journals and replacing with a fitted aluminum bronze bearing sleeve as aluminum bronze is much more durable and is much more slippery (can be honed finer)

Keeping this in mind, it seems counter intuitive with respect to spinning assemblies. I'm thinking of the recent technology that has occurred with ceramic ball bearing setups. Especially in turbo chargers. Journal bearings were old school and couldn't really effectively touch what the new ball bearings reach. The friction is kept low by the materials used, same as you have raised.

The viscosity of the oil in the bearing would definitely play a huge roll in the friction reduction, however that same viscosity is in the journal bearing and as it heats the viscosity reduces which also strips away protection from the bearing. Given those facts would we see a big decrease in friction loses? Probably not. But I'd still like to see real world tests performed on this.

I think biggest development would be ceramic ball bearings since their finish and heat resistance is top notch. Couple this with the ability to handle the forces and it is a rather nice setup to run on the bearing.

Granted though this is all conjecture I would love to read the SAE papers you have on this, or any articles concerning this.