New view of the ED-700 engine and 18-cylinder W-shaped engine. It delivered 700 HP.

"The USA Air Services ED-700"

-Around 1920 the Engineering Division of the US Army Air Services, at McCook Field in Dayton, Ohio, had developed two engines that became known as the Broad Arrow model E.D. 700 (Engineering Division 700), also known as the W.1.

-It gave 700 HP at 1,00 rpm, and it was an 18-cylinder W-shaped engine.

-An larger and more powerful brother was developed, the E.D. 1000, also known as the Broad Arrow, with 1000 HP at 1400 rpm and later known as the W.2.

-They had four valves and four spark plugs per cylinder, and four magnetos.

-See Almen also for its relationship with the USA Air Service.

This is the same service that bore the name "United States Air Corps" and sometimes "USA Air Services."

-Established at Wright Field (previously called McCook Field). Later, with the creation of the USAF, the Engineering Division moved to what would become the new Wright-Patterson AFB, also in Ohio.

-The piston engines designed in the Division's first stage were the Model W.1 and later the W.2.

"Photograph of the W.1"

-The W.1 was a three-row W engine with a total of 18 cylinders, that is six per row.

-It was first completed in 1920. Bench results exceeded expectations, producing 750 HP at 1,800 rpm and 700 HP at 1,700 rpm.

“Schematic view of the W.1”

-The schematic view shown is a rear view with a mid-section on the right side.

-It had six Stromberg carburetors.

-The W.2 model, very similar in principle to the previous one, was larger and also had 18 cylinders. It had a larger displacement and was capable of producing 1,000 HP at 1,400 rpm.

-Following the production of the W-1, the W-1A was produced with structural improvements. Later, the W-1B was produced.

“Air Services W-1B”