Maintenance & Troubleshooting for Portable and Standby Diesel Generators
Generator Break In Period
All engines require some kind of break-in period. Current technology provides the means of manufacturing engine parts with unimaginable precision but they still fall short of achieving the near perfect fit that a proper break-in will provide. “Break-in,” for the most part, is the allowance of the machined cylinder and ring surfaces to conform to each other’s shape during engine operation. This conforming or “mating” of ring and cylinder surfaces is the ultimate goal of a proper break-in. “Mating” these two specific parts will produce a very tight seal in each cylinder. A tight seal is very important because it prevents the escape of unburned fuel and pressurized gasses into the crankcase, while further preventing crankcase oil from entering the cylinder above the top compression ring.
Break-in can occur in the first 100 hours of use. The first 20 are critical and will determine how long your engine will last and run in the future. Avoid heavy loading as it introduces more fuel into the combustion chamber, increases the amount of heat generated and will promote any existing blow by oil to flash burn and glaze to the cylinder walls. This glaze will build up and result in a poor seal. Under loading on the other hand is also bad for the engine. Decreased combustion chamber pressures cause piston rings to not seal as well and to hydroplane or skip over the oil film leaving behind trace amounts that will also burn and glaze to the cylinder walls.
Remember that during the break-in period there is more friction from surfaces mating to each other. Watch for overheating and dirty oil filters.
Synthetic motor oil intended for diesel engines ONLY should be used. The more often you can change your oil the longer your engine will last.
After your break in period remember Diesels are designed to work, and in many cases, they operate best under a load.