To much good stuff to resist posting a long one.
First: The Yamaha TZ750 dirt bike. Jack was right, that engine was just to peaky to be able to get traction and that was really a function of it being a two stroke with expansion chamber dynamics that made the horse power peak narrow. Although Kenny Roberts did win the Indy mile on one in absolutely one of the most exciting finishes ever. He was in second on the last lap, one of the Harley boys was leading, well Kenny knew if he could get a good drive of the last corner, i.e. traction, he could win. So he laid it in to turn four and got the wheel against the cushion, rolled on the throttle and it hooked up and he blew by the Harley right at the finish. Man was the Harley guy surprised!
More TZ750 stuff: When Don Vesco set the world motorcycle record with his liner with two of the TZ750 in it he said the biggest problem was getting the thing to hook up when the engines came on the power ban, it would just spin the tire. Although he set the record he came back next with a pair of turboed Kawasaki 900s and as I understand it he would short shift until he got into high gear and then he would turn the boost up adding horse power as fast as the tire could take it. Jack probably has some good recollections of both of these engine combinations.
Torque and horse power: Remember it is horsepower that makes you go fast, especially at B'ville. Horse power is a measure of work, i.e. force expended over a distance where as torque is just a measurement of force about and axis. So you can have a jillion lb-ft of torque but at zero rpm you are doing no work so you aren't going any where. So if you couple two 100 hp motors together, you will get 200 hps and also twice the torque.
Singles, twins, fours, twingals etc. Seldom, every thing that you say in your post regarding power pulse etc is true for an ideal engine, which would be an engine with a moment of inertia of zero and a structural stiffness of infinity. Not many of those around so we have reciprocating weight, the rods and pistons, and rotating mass, the crank and flywheel all of these combine to make a spring/mass system that actually attenuates the firing pulses of the engine to take out or at least reduce the sharp peaks that we would see if we had the "perfect" engine, i.e. no mass, infinite stiffness. There was a very good article in "Cycle" mag a couple of months ago by Kevin Cameron, I think, about using heavy flywheels to calm down cam shafts. now I admit that this sounds like the two are not connected but read the article and you can see what affect adding rotating inertia has on smoothing out the firing pluses of the engine and how this can keep the cam from throwing the lifters off of the cam face. So my thinking would be if you have an engine that is really peaky but makes good power add fly wheel until it is calmed down and at B'ville the reduced rate of engine acceleration would probably not be noticed as it is the big V cube (speed the power of three) that we are fighting and at the top speed of a vehicle drag is much more of a force than accelerating additional flywheel weight.
Just some rambling please feel free to through me under the bus.
Rex
