S&S Cycle 640 Easy Start Cam Kit For Harley Twin Cam The new Easy Start Cams from S&S Cycle make hard starting obsolete. Here's how it works: Each of the two exhaust cam lobes are equipped with a spring loaded compression release lobe on the heel of the cam at the point where the valve would normally be fully closed. The lobe holds the exhaust valve open slightly at cranking speed, which releases some of the compression, making the engine much easier to crank Once the engine starts and RPM increases, the compression release lobe is centrifugally retracted and the engine runs normally, with full compression, and without any loss in performance. Features: Start any engine regardless of displacement or compression ratio with a stock starter Centerline Intake: 107.5 Duration Exhaust .020: 270 Grind: 640C Lift Top Dead Center Intake: .228 Duration Intake .020: 265 Lift Top Dead Center Exhaust: .214 Lift: .640 Valve Timing Exhaust: 65/25 Centerline Exhaust: 110.0 Valve Timing Intake: 25/60