The main bearings of a reciprocating air compressor are tapered roller bearings. When mounted, these bearings are given a 'cold' end clearance to __________.

Correct Answer: Option A — allow for longitudinal expansion of the crankshaft as the unit warms up

Tapered roller bearings require specific end clearance to accommodate thermal expansion of the crankshaft during operation. Without this 'cold' clearance, the crankshaft would expand as it heats up, creating excessive axial thrust that could bind the bearings, cause overheating, and lead to catastrophic failure of the compressor's rotating assembly.