Question

A says that balance shafts always rotate at crank speed.

B says that balance shafts are found only on V4 engines

-A
-B
-Both
-Neither

Answer 1

Balance shafts typically rotate at twice the crankshaft speed to counteract vibrations and are not exclusive to V4 engines; they can be found in other engine types, including inline-4 and V6 configurations.

Step-by-step explanation:

The question deals with the topic of balance shafts in engines, specifically relating to their speed of rotation and the types of engines in which they are found. A's statement that balance shafts always rotate at crank speed is partially true because in most designs, balance shafts rotate at twice the crankshaft speed to counteract the second-order vibrations, but there are configurations where they may rotate at crank speed. B's statement that balance shafts are found only on V4 engines is incorrect; balance shafts can be found in various types of engines, including inline-4 and V6 engines, where their purpose is to reduce vibration.