is it possible to use roller bearings on the crankshaft? also with that using them on where the piston rods connect to crankshaft?

 

Yes, it is technically possible, however, the cost would be hugely prohibitive. Issues I can think of at the moment:

• There would be a space/packaging issue which would mean either a smaller diameter for the crank journals (which would significantly weaken the crank) and/or a larger (and heavier) rod end (which causes a secondary issue of clearance inside the block and more stress on the crank).
• Then there is the issue of oiling; if roller bearings are employed then the oiling system would have to be completely redesigned to allow the oiling of the rod bearings and the cylinder walls. Currently oil to transits from the block, through the crank (via the main journals to a drilled oil gallery reaching out to the rod journals) and into the rod end (via said rod journals); roller bearings would make this virtually impossible.

Long story short, yes it is technically possible if the engine is designed that way from the start; retrofitting an existing engine would be virtually impossible without costing many times the value of the car.