Continental R-670

R-670
	Continental W670 on display
Type	Piston aircraft engine
Manufacturer	Continental Motors
First run	1934
Major applications	PT-17 Stearman ; M3 Stuart

The Continental R-670 (factory designation W670) was a seven-cylinder four-stroke radial aircraft engine produced by Continental displacing 668 cubic inches (11 litres) and a dry weight of 465 lb (211 kg). Horsepower varied from 210 to 240 at 2,200 rpm. The engine was the successor to Continental's first radial engine, the 170 hp Continental A-70. This engine was used on many aircraft in the 1930s and 1940s. The R-670 was widely used in the PT-17 Stearman primary training aircraft of the U.S. military.^[1]

In addition to being used in aircraft, the R-670 was used in a number of light armored vehicles of World War II.

Variants

Data from: Jane's All the World's Aircraft 1938^[2] Variants of the W670 included:

W670-K: carburetor, 5.4:1 compression, 65 Octane, front exhausts and 225 hp (168 kW)
W670-L: carburetor, 5.4:1 compression, 73 Octane, rear exhausts and 225 hp (168 kW)
W670-M: carburetor, 6.1:1 compression, 80 Octane, front exhausts and 240 hp (179 kW)
W670-N: carburetor, 6.1:1 compression, 80 Octane, rear exhausts and 240 hp (179 kW)
W670-K1: fuel injection, 5.4:1 compression, 73 Octane, front exhausts and 230 hp (172 kW)
W670-L1: fuel injection, 5.4:1 compression, 73 Octane, rear exhausts and 230 hp (172 kW)
W670-M1: fuel injection, 6.1:1 compression, 80 Octane, front exhausts and 250 hp (186 kW)
W670-N1: fuel injection, 6.1:1 compression, 80 Octane, rear exhausts and 250 hp (186 kW)

Applications

Aircraft

American Airmotive NA-75
Boeing-Stearman Model 75 (PT-17, N2S)
CallAir Model A
Cessna 190
Eagle Aircraft Eagle 220
Fairchild PT-23
Funk F-23
G class blimp
Grumman G-164 Ag Cat
Kellett K-2A, K-4
Morane-Saulnier MS.317
Timm N2T Tutor
Waco 240-A
Waco Standard Cabin series (UEC, UIC, UKC, UKC-S, UKS, VKS)
Waco Custom Cabin series (UOC, VQC)
Waco A series (UBA, ULA)
Waco F series (UBF, UMF, UPF)

Armored fighting vehicles

T2 Combat Car
T4 Combat Car
M1 Combat Car
M2 Light Tank
M3 Stuart
Landing Vehicle Tracked (LVT-2, -4; LVT(A)-1, -2, -4, -5)

Specifications (R-670-K)

An R-670 fitted to a Boeing Stearman at the Imperial War Museum Duxford

Data from Jane's 1938^[2]

General characteristics

Type: Seven cylinder air-cooled radial
Bore: 5+1⁄8 in (130.2 mm)
Stroke: 4+5⁄8 in (117.5 mm)
Displacement: 668 cu in (10.95 L)
Length: 34+3⁄16 in (868.4 mm)
Diameter: 42+1⁄2 in (1,079.5 mm)
Dry weight: 450 lb (204.1 kg)

Components

Valvetrain: 1 inlet and 1 exhaust valve per cylinder
Fuel system: 1 Stromberg NA-R6 Carburetor
Fuel type: 65 octane
Oil system: Dry sump, one pressure pump, one scavenge pump, enclosed valve-train
Cooling system: Air-cooled

Performance

Power output: 225 hp (168 kW) at 2,175 rpm
Specific power: 0.337 hp/in³
Compression ratio: 5.4:1
Fuel consumption: 13 US Gal/hr (49 L/hr) at cruising rpm
Specific fuel consumption: 0.54 lb/hp/hr (0.328 kg/kW/hr) - at rated rpm
Oil consumption: 0.4 US Gal/hr (1.5 L/hr) at cruising rpm
Power-to-weight ratio: 0.49 hp/lb at cruising rpm

References

Notes

^ Gunston 1989, p.42.
^ ^a ^b Jane's All the World's Aircraft 1938. London: Sampson, Low & Martin company Limited. 1938.

Bibliography

Gunston, Bill. World Encyclopaedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9
Jane's Fighting Aircraft of World War II. London. Studio Editions Ltd, 1998. ISBN 0-517-67964-7
Jane's All the World's Aircraft 1938. London: Sampson, Low & Martin company Limited. 1938.

External links

https://web.archive.org/web/20070807212519/http://www.oldengine.org/members/diesel/Duxford/usaero1.htm

[1] Gunston 1989, p.42.

[JAWA1938-2] Jane's All the World's Aircraft 1938. London: Sampson, Low & Martin company Limited. 1938.

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