[Michael4yah]

A one pound reduction in the weight of a crank assembly is worth 6 lbs of total weight reduction in a car. Basicly its like this, Youve got two cobras. One with a cast crank and another with a heavier forged crank. The difference is 17 lbs. So in order to make things equal you add 17 lbs of weight to the cast crank car. Now the cars should perform equaly right? Wrong. Overcoming 17 lbs of carried weight is not the same as overcoming 17 lbs of power robbing weight resistance @ the crank. Try this, If you had the same two cars equal in weight and gave each a gallon of gas and told to drive side by side @ 60 miles per hour do you think they would both run out of gas simultaniously? Nope, the car with the forged crank would have to expend more energy because it had to overcome the added resistance weight of the crank. Thats why one of the most important keys to building racing motors is to build a rotating assembly that "just covers" its structural needs. No extra weight. Not just because its carried weight but because its the kind of weight that robs power. In fact in racing if all other things are equal the one that has the smallest margin of strength/weight in this area will win. (As long as it stays glued together and flex or other issues dont play a substantial part.) A gram here a gram there it all adds up. It gets more complicated but this serves as a general basis for building motors. These examples dont work for tractor pulling and other feats of torque. And of course if your running Nitro you might want to keep that forged crank!! Ive never seen a well built properly installed cast crank die in an FE unless it was in a much higher hp engine than we're talking here. Anyway, thats my 2 cents. Michael