I think it is called wrist pin

the portion of a crank between the crankpin and the shaft or between adjacent crankpins -called also crank arm, crank throw

Torque begins as the piston is thrust down the bore on the power stroke. Stroke is the distance the crankpin is offset from the crankshaft centerline X2. The further the crankpin is from the crank centerline the more mechanical leverage granted to the piston. It is a simple lever really and acts as a torque multiplier hence greater net "twist" at the output

The sound is created by the 45 degree angle of the pistons on a single crankpin. Both pistons rise and fall in the cylinders at nearly the same time (45 degrees of crankshaft rotation apart). Most V engines have separate crankpins for each piston.

What makes the Harley-Davidson V twin motor sound the way it does is the basic layout of the motor. It's a 45 degree V and both connecting rods ride on the same crankpin which causes a unique stacato exhaust rhythm. The arrangement also enhances torque output.