Quote Originally Posted by Propless View Post
That's interesting, and you made me go take a better look at my parts. I hadn't noticed it before (never actually looked) but the motor to V-drive shaft (1 3/8") is hollowed out. Its got a 7/8" hole down the center. I guess they really wanted to get every last 10th of a hp they could out of this thing.
The rifle drilling can actually improve the torsional strength of the shaft by increasing the surface area exposed to the rotational stresses. High end crankshafts are drilled front to rear thru the main journals. Most dirt track/sprint car torsion bars are tubular.
The loss of a few ounce of rotational mass is the bonus. Keep in mind, the material in from the center of the shaft, and has much less effect on the "rotational mass" thing.