TOMEI POWERED SR22 Forged Full Countered Crankshaft

Precision Balanced

Full-counter weighted

By preparing counter weight on every cylinder, making inertia power balance so that bent of the crankshaft is suppressed and vibration and friction is reduced, while the reliability of bearing is raised.

2-Route lubrication

Two-route oil supply from two journals secures crankpin an enough amount of oil supply. Moreover, X shape oil passage enables supplying oil using the centrifugal force of a crankshaft, reliability of the oil supply at high RPM is improved. Furthermore, and resistance of oil flow is reduced by giving a modification on oil hole exit.

Edge shape designed with hydrodynamics

At high RPM, counterweight rotates at more than 200km/h inside the crankcase through the oil and air. We designed the edge shape of the counterweight hydro-dynamically sharp so that less resistance will occur even at high rotation.

*1 : If the radius of crank counter weight is 65mm, its circumference is 408mm = 0.4meter. When the engine is running at 8500RPM, crank rotates 141.7 turns per second which is translated in 56.7m/s = 204.1km/h of peripheral speed.