Willys Hurricane engine

The Willys F4-134 Hurricane was an inline-4 piston engine and powered the famous Jeep CJ in the CJ-3B, CJ-5, and CJ-6 models. It was also used in the Willys 473 and 475 pickups, wagons, and sedan deliveries. It replaced the Willys Go Devil engine which was used in the Military Jeep and other early Jeep-based models like the Jeepster.

Design
The Hurricane is one of the few "F-Head" engines, and the only one well known, apart from those produced by Rolls Royce and Rover. The "F" comes from having one set of valves in the block, like a flat (or "L") head, and one set in the head, like a modern OHV engine. The reason Willys did this was because they started from an existing L-head block and modified it to put the intake valves in a new, much taller head. This created a very compact combustion chamber and a higher compression ratio, boosting power.

When introduced in 1950, the F-134 with its 75 hp was the most powerful 4-cylinder engine mass-produced in America.

F134
The L134 Go Devil was updated with the F-head to become the F134 in 1950. This engine produced 75 hp at 4000 rpm (although it redlines at 3200 rpm) and 114 lb of torque at 2000 rpm with a 7.5:1 compression ratio. Bore and stroke dimensions were the same as the L-head engine at 3.125" x 4.375" giving 134.22 cu in (2200 cc).

The F4-134 was introduced in 1950 in the new 473 trucks. However, it was not placed in a CJ until the introduction of the CJ-3B in 1953, which had a distinctive high hood to accommodate the much taller engine. The engine remained in production until 1971, after American Motors Corporation (AMC) purchased Kaiser Jeep.

Applications:
 * 1950 Willys-Overland Jeepster
 * 1966-1971 Jeepster Commando
 * 1953-1968 Willys CJ-3B
 * 1955-1971 CJ-5
 * 1956-1971 CJ-6
 * 1950-1961 Willys Jeep Truck
 * 1950-1961 Willys Jeep Wagon
 * 1953 Willys 475A Lark
 * 1952-1971 Willys M38A1

F161
The F6-161 Hurricane was an F-head version of the L6-161 Lightning flathead straight six. It was used in Jeepsters and Wagons.

BF-161 The BF-161 had a 3 $1/8$ inch bore and a 3 $1/2$ inch stroke, a one-barrel carburetor and an output of 90 hp at 4400 rpm and 135 lb of torque at 2000 rpm. It had a displacement of 161.1 cubic inches (2,639 cc). It had a compression ratio of 7.6:1.

2600 The 2600 was essentially the same as the BF-161, but it had two-barrel carburetor and had an output of 130 hp at 4400 rpm and 140 lb of torque at 2000 rpm. The compression ratio remained 7.6:1.

3000 The 3 litre (184 cid) had its stroke increased to 4 inches, and had a displacement of 3,016 cc (184.1 cid). It had a 2-barrel carburetor and an output of 140 hp at 4400 rpm and 161 lb of torque at 2000 rpm. It also had a slightly higher compression ratio of 8:1.

Super Hurricane
6-226 An L-head 6 cylinder from Continental with a bore of 3.3125" and stroke of 4.375" giving a displacement of 226.22 cuin (3.71 L). Several references show a bore of 3.94" but this is incorrect. Horsepower rating is 205 hp at 3600 rpm or 115 hp at 3800 rpm, as well as a torque rating of 190 lb at 1400 rpm or at 1800 rpm, depending on the year of production.