| 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)

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
 
See also
Comparable engines
Related lists
References
Notes
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.
 
