What is the main purpose of engine running-in after overhaul?
1 Answers
The purpose of engine running-in after major overhaul is to ensure a tight seal between piston rings and cylinder walls. To guarantee running-in effectiveness and protect engine performance, the engine running-in process must be strictly operated and completed according to relevant procedures. Engine running-in refers to the trial operation that adopts specific motion condition parameters and working specifications according to engine characteristics, aiming to make the surface conditions and mechanical-physical properties of new or overhauled engine assemblies reach a state suitable for long-term operation. Engine running-in generally consists of three stages: cold running-in, hot running-in, and dynamometer testing. Cold running-in uses external power as the power source to operate main engine components under sufficient lubrication conditions with regulated speed variation and increasing loads. Hot running-in uses the properly functioning engine itself as the power source, systematically varying speed and increasing loads under normal working conditions until reaching rated power and speed. Dynamometer testing measures fuel consumption and power output at rated speed conditions to evaluate the quality of engine assembly, manufacturing, or repair.
