From the preceding discussion, it can be readily seen that, in general, the result of unbalance will be overheating of the engine. The clearances established by the engine designer allow for sufficient expansion of the moving parts when the engine is operating at the designed temperatures, but an engine operating at temperatures in excess of those for which it was designed is subject to many casualties. Excessive expansion soon leads to seizure and burning of the engine parts. Should the temperatures in the crankcase rise above the flash point of the lubricating oil vapors, an explosion may result. High temperature may destroy the oil film between adjacent parts, and the resulting increased friction will further increase the temperature. Since power is directly proportional to the mep developed in a cylinder, any increase in mep will cause a corresponding increase in power. If the meps in the individual cylinders vary, power will not be evenly distributed among the cylinders.

The quality of combustion obtained depends upon the heat content of the fuel. The amount of heat available for power depends upon temperature. Temperature varies directly as pressure; therefore a decrease in pressure will result in a decrease in temperature, and in poor combustion. Poor combustion will cause lowered thermal efficiency and reduced engine output. Cylinder load balance is essential if the desired efficiency and performance of an engine is to be obtained. To avoid the harmful effects of overloading and unbalancing of load, the load on an engine should be properly distributed among the working cylinders; and no cylinder, or the engine itself, should ever be overloaded. In general, load balance in an engine can be maintained if the following procedures are observed:

1. Maintain the engine in proper mechanical condition.

2. Adjust the fuel system according to the manufacturers instructions.

3. Operate the engine within the temperature limits specified in appropriate instructions.

4. Keep cylinder temperatures and pressures as evenly distributed as possible.

5. Train yourself to recognize the symptoms of serious engine conditions.