Crankshaft

On the top a stock Honda crankshaft. On the bottom a Honda crankshaft lightened by Powroll. Basically all that was done was the removal of metal along the edges of the crank throws. This is commonly called knife edging, it reduces the weight of the crank and also the sharper outside edge allows it to cut through the oil in the crankcase easier. Only about .6 - .7 lbs was removed from the stock crankshaft. Better than stock balancing was achieved by drilling a 3/4" hole in the crank throws, this is not shown in the photo and I assume the placement of this hole would vary from one part to another. I have seen examples of crankshaft for small Hondas in Europe that have been extensively lightened by removing much more metal than this example.