Reciprocating Engine Lubrication Systems – Airflow Controls

Lubrication and Cooling Systems

By regulating the airflow through the cooler, the temperature of the oil can be controlled to fit various operating conditions. For example, the oil reaches operating temperature more quickly if the airflow is cut off during engine warm-up. There are two methods in general use: shutters installed on the rear of the oil cooler, and […]

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Reciprocating Engine Lubrication Systems – Surge Protection Valves

Lubrication and Cooling Systems

When oil in the system is congealed, the scavenger pump may build up a very high pressure in the oil return line. To prevent this high pressure from bursting the oil cooler or blowing off the hose connections, some aircraft have surge protection valves in the engine lubrication systems. One type of surge valve is […]

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Reciprocating Engine Lubrication Systems – Oil Coolers

Lubrication and Cooling Systems

The cooler, either cylindrical or elliptical shaped, consists of a core enclosed in a double-walled shell. The core is built of copper or aluminum tubes with the tube ends formed to a hexagonal shape and joined together in the honeycomb effect. [Figure 6-11] The ends of the copper tubes of the core are soldered, whereas […]

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Reciprocating Engine Lubrication Systems – Oil Pressure Gauge

Lubrication and Cooling Systems

Usually, the oil pressure gauge indicates the pressure that oil enters the engine from the pump. This gauge warns of possible engine failure caused by an exhausted oil supply, failure of the oil pump, burned-out bearings, ruptured oil lines, or other causes that may be indicated by a loss of oil pressure. One type of […]

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Reciprocating Engine Lubrication Systems – Oil Pressure Regulating Valve

Lubrication and Cooling Systems

An oil pressure regulating valve limits oil pressure to a predetermined value, depending on the installation. [Figure 6-6] This valve is sometimes referred to as a relief valve but its real function is to regulate the oil pressure at a present pressure level. The oil pressure must be sufficiently high to ensure adequate lubrication of […]

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Reciprocating Engine Lubrication Systems – Oil Filters

Lubrication and Cooling Systems

The oil filter used on an aircraft engine is usually one of four types: screen, Cuno, canister, or spin-on. A screen-type filter with its double-walled construction provides a large filtering area in a compact unit. [Figure 6-6] As oil passes through the fine-mesh screen, dirt, sediment, and other foreign matter are removed and settle to […]

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Reciprocating Engine Lubrication Systems – Oil Pumps

Lubrication and Cooling Systems

Oil entering the engine is pressurized, filtered, and regulated by units within the engine. They are discussed along with the external oil system to provide a concept of the complete oil system. As oil enters the engine, it is pressurized by a gear-type pump. [Figure 6-6] This pump is a positive displacement pump that consists […]

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Reciprocating Engine Lubrication Systems – Oil Tanks

Lubrication and Cooling Systems

Oil tanks are generally associated with a dry sump lubrication system, while a wet sump system uses the crankcase of the engine to store the oil. Oil tanks are usually constructed of aluminum alloy and must withstand any vibration, inertia, and fluid loads expected in operation. Each oil tank used with a reciprocating engine must […]

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Reciprocating Engine Lubrication Systems – Dry Sump Oil Systems

Lubrication and Cooling Systems

Many reciprocating and turbine aircraft engines have pressure dry sump lubrication systems. The oil supply in this type of system is carried in a tank. A pressure pump circulates the oil through the engine. Scavenger pumps then return it to the tank as quickly as it accumulates in the engine sumps. The need for a […]

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