Radial motorcycle engine with multiple cylinders

Radiused piston head

Remote control oil sump drain valve

Remote operated drain for an oil pan

Replacement oil drain plug

Retractable marine thrust motor

Reversible thrust motor for laterally maneuvering the stern of a

Rocker arm assembly

Rocker arm cover

Rocker cover

Rod-end bearing

Rodless cylinder

Rodless cylinder

Rodless cylinder with a movable table

Rodless cylinder with a slider

Roller bearing for a crankshaft

Roller rocker arm

Rotary engine

Rotary vane combustion engine

Rotor for an internal combustion engine