Browse Aircraft Engine Crankcase Parts Catalog

The aircraft engine crankcase is the body that holds all engine components together. While it is the largest part of the engine and must be very strong, it cannot be so heavy that it hinders aircraft performance. In two-stroke engines, a crankcase-compression design is implemented, allowing the fuel/air mixture to pass through the crankcase before entering the cylinders. Four-stroke engines feature an oil sump at the crankcase base and the majority of the engine’s oil is held in the crankcase. In this configuration, the fuel/air mixture does not pass through the crankcase.

There are four types of crankcase configurations. Two are found in two-stroke engines and two more in four-stroke engines. The two-stroke engine crankcases are crankcase-compression and lubricating crankcase configurations. In four-stroke engines, there are the oil circulation and combustion ventilation configurations. The crankcase-compression configuration operates through a partial vacuum drawing fuel and air into the engine as the pistons move upward. This uncovers the inlet port, allowing the fuel/air mixture to enter the combustion chamber. Larger two-stroke engines do not use a compression crankcase, but a supercharger to draw the fuel/air combination into the compression chamber. This type is only used for lubrication purposes.

In the four-stroke oil circulation configuration, engine oil is pressurized by a pump before being sent into the crankshaft, eventually dripping into the oil sump in the bottom of the crankcase. Four-stroke engines use a crankcase ventilation system to prevent the extra combustion gases from staying in the crankcase. These gases, called blow by, can cause unwanted pressurization of the crankcase, contamination of the oil, and rust as a result of the condensation. For all your aircraft engine crankcase parts, ASAP Part Services is at your disposal. We are a leader among independent distributors due to our impressive inventory and supply chain which allow us to promise short lead times and competitive prices. To begin the purchasing process, submit an RFQ today.