The Continental R-670 (factory designation W670) was a seven cylinder four-cycle 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.
In addition to being used in aircraft, the R-670 was used in a number of light armored vehicles of World War II.
Data from: Jane's All the World's Aircraft 1938 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)
American Airmotive NA-75
Boeing Stearman
CallAir Model A
Cessna 190
Fairchild PT-23
G class blimp
Timm N2T Tutor
Waco 240-A
Waco UEC and UIC
Waco VKS-7
Waco QCF-2
T2 Combat Car
T4 Combat Car
M1 Combat Car
M2 Light Tank
M3 Stuart
LVT-4 Water Buffalo
Data from Jane's 1938
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)
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
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