Exchanging a pulley for one with a different diameter changes the __________.

Exchanging a pulley for one with a different diameter changes the __________.

• A. crankshaft stroke
• B. drive-to-driven ratio
• C. valve lift
• D. belt tension

Answer: (B)

Changing the pulley to a different diameter directly alters the drive-to-driven ratio, which sets how fast the driven pulley turns relative to the driver. If the drive pulley is larger than the driven one, the driven rotates more slowly (more torque, less speed); if the drive is smaller, the driven speeds up (less torque, more speed). This ratio is the fundamental effect of swapping pulleys. The crankshaft stroke is fixed by the engine’s geometry, and valve lift depends on cam timing and profile, not simply on pulley size. Belt tension can shift with load, but the immediate consequence of changing pulley diameter is the change in the drive-to-driven speed ratio.

Changing the pulley to a different diameter directly alters the drive-to-driven ratio, which sets how fast the driven pulley turns relative to the driver. If the drive pulley is larger than the driven one, the driven rotates more slowly (more torque, less speed); if the drive is smaller, the driven speeds up (less torque, more speed). This ratio is the fundamental effect of swapping pulleys. The crankshaft stroke is fixed by the engine’s geometry, and valve lift depends on cam timing and profile, not simply on pulley size. Belt tension can shift with load, but the immediate consequence of changing pulley diameter is the change in the drive-to-driven speed ratio.