Wright Vertical 4

The Wright Vertical 4 was an American aircraft engine built by the Wright brothers in the very early years of powered flight. It was a liquid-cooled piston engine with four inline cylinders, mounted vertically. (Earlier Wright engines were mounted horizontally.) It generated about 30–40 horsepower (22–30 kW) from a displacement of 240 cubic inches (3.9 liters) and weighed about 160–180 pounds (73–82 kg). Developed by Orville Wright in 1906, the Vertical 4 was produced by the Wright Company until 1912 and was the most numerous engine they manufactured.^[3][4] Around a hundred Vertical 4 engines were built, according to a Wright test foreman.^[1][2]

Wright Vertical 4
Wright Vertical 4 aircraft engine on display at the Steven F. Udvar-Hazy Center. This particular engine was used on the Wright B-1 seaplane that crashed in 1912. A patch was bolted to the side of the crankcase in an attempt to repair the engine.
Type	Liquid-cooled inline-4 piston aero engine
National origin	United States
Manufacturer	Wright Company
Designer	Orville Wright
Major applications	Wright Model A Wright Model B
Number built	around 100[1][2]

The Vertical 4 powered most Wright aircraft during this period, including the Model A and Model B and variants built for the U.S. Army and Navy.

This engine was also built under license by Bariquand et Marre in France and by Neue Automobil-Gesellschaft in Germany.^[5][2]

Applications

• Wright Model A
• Wright Model B
• Wright Model R

Engines on display

Wright Vertical 4 engines can be seen on display in the following museums, among others:

• National Air and Space Museum, Washington, D.C.
• Steven F. Udvar-Hazy Center, Chantilly, Virginia
• Wright Brothers Aviation Center in Carillon Historical Park, Dayton, Ohio
• Hiller Aviation Museum, San Carlos, California
• New England Air Museum, Windsor Locks, Connecticut
• Museum of Science and Industry, Chicago, Illinois
• National Museum of Flight, East Fortune, Scotland

Specifications

Right side view of the Wright Vertical 4 on display at the National Air and Space Museum. This engine was originally a keepsake of Orville Wright's.

Data from "Wright Vertical 4, In-line 4 Engine (inventory A19620037000)". Smithsonian National Air and Space Museum. Retrieved 12 June 2018.

General characteristics

• Type: 4-cylinder, liquid-cooled inline piston aircraft engine
• Bore: 4.375 in (111 mm)
• Stroke: 4 in (102 mm)
• Displacement: 240 in³ (3.9 L)
• Length: 40.75 in (1,035 mm)
• Width: 18 in (457 mm)
• Height: 27 in (686 mm)
• Dry weight: 160–180 lb (70–80 kg)^[6][4]
• Designer: Orville Wright

Components

• Valvetrain: overhead valve, two valves per cylinder, "automatic" intake valve (driven by suction), exhaust valve actuated by camshaft and pushrod
• Cooling system: liquid-cooled

Performance

• Power output: Initially 28 hp (21 kW) at 1325 rpm, later up to 42 hp (31 kW) at 1500 rpm.^[6][4]