Por lo que averigue en la web, parece ser que el motor era un Wisconsin de 4 cilindros y 55 HP
Specifications:
FWD Model B
Engine: 389.6ci Wisconsin
Power: 50 hp @ 1300 rpm
Torque: 222 lbs-ft @ 1300 rpm
Comp. Ratio: 4:1
Transmission: 3-speed, 4:1 1st gear
Transfer Case: Single-speed, full-time, 2.06:1 ratio
Front Axle: Full-float, FWD
Rear Axle: Full-float, FWD
Axle Ratios: 4.30:1
Tires: 36 x 6 solid rubber, cast-iron rim
Wheelbase: 124 in.
Fuel Capacity: 30 gal.
Curb weight: 7,308 lbs
Top speed: 16 mph
FWD Model B Ammunition Carrier
One of the trucks most remembered by veterans of World War I is this 3-ton, four-wheel-drive Ammunition Carrier built by the Four Wheel Drive Auto Cmpany, later named FWD Corporation, Clintonville, Wisconsin. More than 20,000 of these famed Model "B's" as they were called, hustled guns, ammuntion, troops and supplies to the battle fronts in the service of U.S. and allied fighting forces (FWD Museum pamphlet).