The crankshaft is made from low all

The crankshaft is made from low alloy forged steel and is fully machined for added strength. Stress tends to concentrate on surface irregularities, such as casting and forging marks. These concentrations are called stress raisers. Stress concentrations are removed and the crankshaft is made stronger by removing these stress raisers through machining. The AT crankshaft is also fully counterweighted for smoother operation and longer bearing life. A fully counterweighted crankshaft also rotates closer to the center of the main bearing bore. This type of operation means a more consistent oil film thickness and longer bearing life. Note that the AT crankshaft incorporates two flanges for full power transmission at each end. A larger bearing journal means lower unit loading and longer bearing life. On the AT crankshaft this is accomplished without compromising cylinder bore spacing, by the use of undercut fillets. Also visible on this slide is a drive gear on each end of the crankshaft. The gear on the front of the crankshaft drives the oil and water pumps, while the rear gear drives the camshafts. There will be more to say about this later.