Rxmotor Honda Civic Si RSX K20 Performance Motor CNC Crank Shaft Pulley Wheel Kit Blue FITMENT: Acura / Honda K-Series Engines Only. [Attention: Will Work On Either K20 / K24 Engine] Some Models will require Engine Swap of A K-Seires Engine Acura / Honda K-Series Light Weight Aluminum Underdrive Crankshaft Pulley Wheel CNC Machined From AL6061-T6 Billet Aluminum With An Anodized Finish. Helps Stabilizes Engine At Higher RPM. Perfect For High Modified Engines For Track Or Street Use Factory Timing Mark For Easy Timing Checks And Changes. Increases Throttle Response, While Freeing Up Lost Horsepower And Torque Extremely Light Weight Allowing Engines To Rev Fast And Accurately