What is a crank case?

A crankcase is an integral part of an internal combustion engine. It is an enclosed metal casing that houses the crankshaft and other components of the engine's bottom end. The primary function of the crankcase is to support and protect the crankshaft while also serving as a reservoir for engine oil.

Here are some key points about the crankcase:

1. Location: The crankcase is usually located below the cylinders and above the oil pan in a typical engine configuration.

2. Construction: Crankcases are commonly made of cast iron, aluminum, or sometimes a combination of both. These materials are chosen for their durability and heat dissipation properties.

3. Crankshaft Support: The crankshaft is supported by the crankcase, which provides a rigid structure and prevents excessive vibrations or flexing during engine operation.

4. Lubrication: The crankcase serves as a reservoir for engine oil. The oil is stored in the bottom of the crankcase and is pumped through passages to lubricate various moving parts, including the crankshaft, pistons, and connecting rods.

5. Ventilation: The crankcase is equipped with a ventilation system to ensure that any excess pressure or harmful gases are safely released. This prevents build-up of pressure, which could cause oil leaks or seals to fail.

6. Access Points: The crankcase is typically equipped with several access points, including oil filler caps, drain plugs, and oil level indicators. These allow for easy maintenance and servicing of the engine.

7. Sealing: The crankcase is sealed to prevent oil leaks and to maintain pressure within the engine. Gaskets and seals are used at various points of the crankcase to ensure an airtight seal.

8. Cooling: The crankcase also helps in dissipating heat generated by the engine. As engine oil circulates through the crankcase, it absorbs heat from the engine components, and the crankcase's metal construction helps in dissipating this heat to the surrounding air.

9. Crankcase Breather: The crankcase may have a breather system that allows for the ventilation of gases and pressures while preventing debris or excessive oil mist from escaping. This is especially important in reducing air pollution and maintaining the cleanliness of the engine.

Overall, the crankcase plays a vital role in the smooth functioning and long-term durability of an internal combustion engine. It houses and supports the crankshaft, provides storage for engine oil, assists in cooling, and ensures a sealed environment within the engine.