Angle between cylinders: In the Liberty the included angle between the cylinders is 45°. This angle was adopted to save head resistance, to give greater strength to the crank case, and to reduce periodic vibration. This decision was based on the experience of the Renault and Packard engines.
Electric generator and ignition: The Delco system was adopted, but specially designed for the Liberty to provide a reliable double ignition.
Pistons: The die-cast aluminum-alloy pistons of the Liberty were based on development work by the Hall-Scott Co. under service conditions.
Connecting rods: These were of the forked or straddle type as used on the DeDion and Cadillac automobile motors and also on the Hispano-Suiza and other aviation engines.
Crank shaft: A design of standard practice, every crank pin operating between two main bearings, as in the Mercedes, Rolls-Royce, Hall-Scott, Curtiss, and Renault.
Crank case: A box section carrying the shaft in bearings clamped between the top and bottom halves by means of long through bolts, as in the Mercedes and Hispano-Suiza.
Lubrication: The system of lubrication was changed, this being the only change of design made in the Liberty after it was first put down on paper. The original system combined the features of a dry crank case, such as in the Rolls-Royce, with pressure feed to the main crank-shaft bearings and scupper feed to the crank-pin bearings, as in the Hall-Scott and certain foreign engines. The system subsequently adopted added pressure-feed to the crank-pin bearings, as in the Rolls-Royce, Hispano-Suiza, and other engines.
Propeller hub: Designed after the practice followed by such well-known engines as the Hispano-Suiza and Mercedes.
Water pump: The conventional centrifugal type was adapted to the Liberty.
Carburetor: The Zenith type was adapted to the engine.