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 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]

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]

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

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

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

• 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

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

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

• This article contains material that originally came from the placard at the Steven F. Udvar-Hazy Center.

Hobbs, Leonard S. (1971). Smithsonian Annals of Flight, No. 5: The Wright Brothers' Engines and Their Design (PDF). Washington, D.C.: Smithsonian Institution Press.

Lippincott, Harvey H. (1987). "Propulsion Systems of the Wright Brothers". In Wolko, Howard S. (ed.). The Wright Flyer: An Engineering Perspective. Washington, D.C.: Smithsonian Institution Press. pp. 87–89. ISBN 0-87474-979-4.

McFarland, Marvin W., ed. (1953). The Papers of Wilbur and Orville Wright, Including the Chanute-Wright Letters and Other Papers of Octave Chanute. Vol. Two: 1906–1948. New York: McGraw-Hill. pp. 1215–1216.

Wikimedia Commons has media related to Wright Vertical 4.

• "Wright Vertical 4, In-line 4 Engine". Smithsonian National Air and Space Museum. Retrieved 8 June 2018. (Former keepsake of Orville Wright, inventory A19620037000.)
• "Wright Vertical 4, In-line 4 Engine". Smithsonian National Air and Space Museum. Retrieved 8 June 2018. (U.S. Navy Wright Model B engine, inventory A19520108000.)
• "1906-1912 Wright 4-40 Engine". www.wright-brothers.org. Retrieved 9 June 2018. Further detail on the engine's construction and history, and pointers to references.