Engine | Years | Power | Usage
226 CID Flathead 6 I6 | 1948–51 | 95 hp (71 kW) at 3,300 rpm | F-1 through F-6
239 CID Flathead V8 | 1948–52 | 100 hp (75 kW) at 3,800 rpm | F-1 through F-6
254 CID Flathead 6 | 1948–51 | 110 hp (82 kW) at 3,400 rpm | F-6 only
337 CID Flathead V-8 | 1948–51 | 145 hp (108 kW) at 3,600 rpm | F-7 and F-8
215 CID OHV Straight-6 | 1952–53 | 101 hp (75 kW) |
279 Lincoln Y-block (EAL) | 1952–55 | 145 hp (108 kW) at 3,800 rpm | F-7 only
317 Lincoln Y-block (EAM) | 1952–55 | 155 hp (116 kW) at 3,900 rpm | F-8 only

The original flathead engine displaced 221 cu in (3.6 L), with 3.0625 by 3.75 in (77.79 by 95.25 mm) bore and stroke.[12] The block was cast as a single piece (monobloc) for durability, and a single-barrel carburetor fed the engine. The 1932 V8-18[12] with 5.5:1 compression[12] produced 65 hp. The 1933-34 V8-40 raised compression to 6.33:1[12] and power to 75 hp (56 kW). In 1934 a two barrel down draft carburetor was introduced.[citation needed] 1935's V8-48 saw compression drop to 6.3:1,[12] but power climb to 85 hp (63 kW), and torque was rated at 144 lb·ft (195 N·m).[12] It became the V8-68 in 1936, with compression, horsepower, and torque unchanged.

Production of the original 221 lasted from 1932 through to 1936. These engines can be identified by having the water pumps located at the front of the heads. A similar 221 flathead was used in Fords for 1937 and 1938 but the block was revised to have the water pumps mount to the block. The new design also relocated the water outlet from the front of the heads to the top center of the heads. These, designated V8-78, were offered with standard 6.2:1 compression aluminum or 7.5:1 compression iron cylinder heads,[12] rated at 85 hp (63 kW) and 144 lb·ft (195 N·m) (aluminum) or 94 hp (70 kW) (iron).[12] The 1932 through 1938 motors used twenty one studs to hold down each head and are known as "21 stud" motors. This motor continued to be made into the 1950s in Europe.

In late 1938 Ford introduced V8-81A,[12] commonly called the "24 stud" engine because it uses twenty four studs to hold down each head. This engine debuted at the same time as the 239 motor. With 6.12:1 compression,[12] horsepower remained the same, but torque increased by 2 lb·ft (2.7 N·m). In 1939, as the V8-91A, compression increased to 6.15:1, power rose to 90 hp (67 kW), and torque reached 155 lb·ft (210 N·m);[12] the ratings remained the same for the 1940 V8-01A, 1941 V8-11A, and the last civilian model, the V8-21A, which saw compression rise, to 6.2:1.[12] This engine was used through 1942 for civilian use and saw some use in military vehicles during World War Two. Collectively all 221 motors are commonly referred to as "85 horse" motors.