At what temperature and duration should you immerse a cylinder block before performing pressure testing?

Immersing a cylinder block in water at the specified temperature and duration helps to ensure that the metal expands uniformly, allowing for any potential leaks or weaknesses to be more easily detected during pressure testing. The combination of 93.3ºC (200ºF) for 15-20 minutes is optimal because it brings the cylinder block to a temperature where most engine materials are sufficiently expanded, allowing for a thorough examination of the block under pressure conditions.

This temperature range is high enough to simulate operating temperatures that a cylinder block might reach in regular use. Additionally, allowing it to soak for 15-20 minutes provides enough time for the heat to permeate the entire block, ensuring that the entire structure is tested uniformly, covering potential weak points that might not be detectable at lower temperatures or shorter durations.