20.15.
Engine Break-in
If the engine overhaul and installation are performed properly, the engine should crank and start on its own fully charged battery without the use of a fast charger or jumper. Once the engine starts and shows oil pressure, it should be brought up to a fast idle speed and held there. This is necessary to ascertain that the engine gets proper lubrication. The fast turning oil pump develops full pressure and the fast turning crankshaft throws adequate oil on the cam and cylinder walls.
As soon as it is assured that there are no serious leaks and the engine is running reasonably well, the automobile is driven to a road with minimum traffic. Here, the automobile is accelerated, full throttle, from 48 to 80 kmph and, with the throttle fully closed the automobile is allowed to return to 48 kmph. This sequence should be repeated from 10 to 12 times. The acceleration sequence loads the piston rings to properly seat them against the cylinder walls. The piston rings are the only part of the modern engine that need to the broken in. Good ring seating is indicated by a dry white coating inside the tailpipe at the completion of the ring seating sequence.
The automobile is brought back to the service area where the basic ignition timing and idle speeds are properly set. The engine is again checked for visible fluid leaks. If the engine is dry, it is ready to hand over to customer. The customer should be instructed to drive the automobile in a normal fashion, neither babying it at slow speeds nor beating it at high speeds for the first 160 km. The oil and filter should be changed at 800 km to remove any dirt that got into the engine during assembly and to remove the material that has worn from the surfaces during the break-in period.
A well-designed engine that has been correctly reconditioned and assembled using the techniques described should give reliable and durable service for many kilometres. Premature failure results from problems that have been overlooked or from operational abuse.
