A gasoline powered engine configured to operate in a substantially horizontal orientation and to be stored in a generally vertical orientation without leaking of fluid contained in the gasoline powered engine may include an oil sump and a first oil drain port extending in a first direction through a first wall of the sump. The first wall forms a bottom of the sump when the engine is in the vertical orientation.

Aircraft engine oil tanks, lubrication systems, and associated methods are provided. The oil tank includes a first tank portion defining a first volume for holding oil and a second tank portion defining a second volume for holding oil, in fluid communication with the first volume. The first tank portion includes an oil outlet for delivering oil to a lubrication load via a pump. The first volume is in fluid communication with a vent opening for venting the oil tank. At least part of the second tank portion is disposed higher than the vent opening for retaining a quantity of oil inside the oil tank during a negative-g force flight condition and facilitate the recovery of the lubrication system following the negative-g force flight condition.

A gasoline powered engine configured to operate in a substantially horizontal orientation and to be stored in a generally vertical orientation without leaking of fluid contained in the gasoline powered engine may include an oil sump and a first oil drain port extending in a first direction through a first wall of the sump. The first wall forms a bottom of the sump when the engine is in the vertical orientation.