The overhaul of the cylinder head is mainly to restore the air tightness of the valve return, remove the carbon deposit on the cylinder head, and replace the valve oil seal, cylinder gasket and other seals. Maintain lubrication, cooling, air intake and exhaust system and ignition (fuel injection) system at the same time.
In addition to the above work, the overhaul of the whole machine also requires the maintenance and replacement of connecting rod bearings, spindle bearings, piston rings, cylinder liners and other parts to improve the service life of the engine.
Engine overhaul time is different for different purposes:
Vehicle engine:
Domestic Didi,
Overhaul of cylinder head is about10.6 million kilometers (about 3,000 hours).
About 300,000 kilometers (about 7,500 hours) of overall overhaul.
Imported vehicle engines can be increased to 250,000 km and 500,000 km this time.
Marine engine:
Domestic drip, used for about two years, about 4000 hours, cylinder head overhaul; It took three years and was overhauled for 6000 hours.
Imported marine engines can grow to 3 years and 6 years respectively.
Engine of generator set:
Domestic drip, used for about 8000 hours, cylinder head overhaul; 20,000 hours, overhaul of the whole machine.
Imported drips will be used for about 20,000 hours, the cylinder head will be overhauled for 40,000-50,000 hours, and the whole machine will be overhauled.
Engines for engineering/industry:
Domestic Didi, overhaul the cylinder head once a year, 1000-2000 hours or so; Overhaul the whole machine every 2-3 years.
Imported drip oil, overhaul the cylinder head once every 3 years and overhaul the whole machine once every 5-8 years.