Maintaining Oil Levels of Wet Sump Engines

In order to avoid confusion over wet sump engines, we are listing examples of them for clarification so that operators, line crews, and maintenance personnel can properly check oil. The following aircraft and engine models carry a capacity of six quarts of oil:

Aircraft Model Engine Model

Cessna Skyhawk 172N O-320-H2AD

Cessna 152 O-235-L2C

Piper Tomahawk O-235-L2C

Beech Skipper O-235-L2C

Piper Seminole (Twin) O-360-E1A6D

Grumman American Trainer O-235-C2C

In addition to the aircraft listed previously, there are others in lesser numbers using these and other engine models with a six quart oil capacity. In order to be sure what an engine requires, consult the Pilotís Operating Handbook.

One problem reported to us concerning the six-quart capacity engines has been that of overfilling the engine with oil. By referring to the Pilotís Operating handbook the pilot will not confuse his engine with those wet sump powerplants that have a capacity of eight quarts of oil.

The Pilotís Operating Handbook for the Cessna models 152, and 172N Skyhawk have the following information concerning the engine oil:

"Capacity of Engine Sump - 6 quarts. Do not operate on less than 4 quarts. To minimize loss of oil through breather, fill to 5 quart level for normal flights of less than 3 hours. For extended flight, fill to 6 quarts. These quantities refer to oil dipstick level readings. During oil and oil filter changes, one additional quart is required when the filter is changed."

The Pilotís Operating Handbook for the Piper PA-44-180 Seminole states as follows concerning oil requirements:

"The oil capacity of the Lycoming engines is 6 quarts per engine with a minimum safe quantity of 2 quarts per engine. It is necessary that oil be maintained at full (6 quarts) for maximum endurance flights."

The phrase ó "a minimum safe quantity of 2 quarts per engine" ó should be explained. If the operator checked oil after a flight and found less than 2 quarts in the engine, it is quite probable that engine damage has resulted. No flight should be started with only 2 quarts of oil in the sump.

Pilots and mechanics should not confuse the models just discussed with other Lycoming four cylinder, wet sump engines that hold a maximum of 8 quarts of oil. There is no change in our recommendations when checking oil for the latter. During normal routine flying, oil levels are best maintained at the 6 to 7 quart level.

Donít forget ó when in doubt, consult the Pilotís Operating Handbook.