The Willys F4-134 Hurricane was an inline-4 F-head piston engine that powered the M38A1 military Jeep in 1952, followed by 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 that was used in the MB Jeep and other early Jeep-based models like the Jeepster. This engine was also built by Mitsubishi for their license-built Jeep, for other applications.

Design

The Hurricane was based on the earlier Go-Devil flathead engine. To enhance power from the engine, the induction system was changed from the Go-Devil's side-valve configuration to an inlet-over-exhaust configuration, or "F-head". This allowed the valves to be larger and the combustion chamber to be smaller, improving flow and increasing the compression ratio. The compression ratio rose from 6.5:1 in the Go-Devil engine to 7.5:1 in the Hurricane engine, although a version of the Hurricane engine was made with a 6.9:1 compression ratio.

F134

The L134 Go Devil was updated with the F-head to become the F134 in 1950. This engine produced a gross output of 75hp (56kW; 76PS) at 4000rpm and 114lb⋅ft (155N⋅m) of torque at 2000rpm with a 7.5:1 compression ratio. The gross power and torque outputs decreased to 72hp (54kW; 73PS) and 112lb⋅ft (152N⋅m), respectively, when the engine had a 6.9:1 compression ratio. Bore and stroke dimensions were the same as the L-head engine at 3+1⁄8 x 4+3⁄8 inches, giving 134.2cuin (2,199cc).

The F4-134 was introduced in 1950 in the Jeep Truck. Willys vehicles with this engine were designated 4-73 model. This engine was unavailable in the CJ series until the introduction of the CJ-3B version in 1953, which had a distinctive high hood to accommodate the much taller engine. Production of this engine continued through 1971, which was after American Motors Corporation (AMC) purchased Kaiser Jeep in 1970.

Applications:

F161

The F6-161 Hurricane is an F-head version of the L6-161 Lightning flathead straight six. It was available in the Model 685 Station Wagon.

BF-161 The BF-161 has a 3+1⁄8 inch bore and a 3+1⁄2 inch stroke, a one-barrel carburetor, and an output of 90hp (67kW; 91PS) at 4400rpm and 135lb⋅ft (183N⋅m) of torque at 2000rpm. Its 161.1cuin (2,640cc) displacement features a compression ratio of 7.6:1.

2600 The 2600 was the same BF-161 engine made in Brazil by Willys-Overland's subsidiary, but it had two one-barrel carburetors (simultaneously opened) and had an output of 130hp (97kW; 132PS) at 4400rpm and 140lb⋅ft (190N⋅m) of torque at 2000rpm. The compression ratio remained 7.6:1.

3000 The 3L version is almost identical to the BF-161 engine, with the stroke increased to 4 inches (101.6mm), giving it a displacement of 3,016.5cc (184.1cuin). With a two-barrel carburetor, it produced 140hp (104kW; 142PS) at 4400rpm and 161lb⋅ft (218N⋅m) of torque at 2000rpm. It also had a slightly higher compression ratio of 8:1. It initially used a different head with a removable intake manifold.

After Ford acquired Willys-Overland do Brasil, they reverted the engine to its former head design with an integral intake manifold. Ford also improved the cooling between cylinders 5 and 6 as well as incorporating a side-mounted oil filter instead of the front-mounted, hose-connected system designed by Willys.

Applications:

Super Hurricane

Super Hurricane engine in 1955 Jeep Willys Utility Wagon

The 6-226 "Super Hurricane" was an L-head 6-cylinder from Continental with a bore of 3+5⁄16inches and stroke of 4+3⁄8inches, giving a displacement of 226.2cuin (3,707cc). Horsepower rating is 105hp (78kW; 106PS) at 3600rpm or 115hp (86kW; 117PS) at 3650rpm, as well as a torque rating of 190lb⋅ft (258N⋅m) at 1400rpm or at 1800rpm, depending on the year of production.

Mitsubishi versions

Mitsubishi built a version of the Hurricane from 1954 as the JH4 (69hp), primarily for use in their license-built version of the Jeep. They later developed a 61PS (45kW) overhead-valve diesel version of the same, called KE31. This was also turned into a 3.3L six-cylinder version with the same internal dimensions, producing 85PS (63kW), which was named KE36. These diesel engines were used in the Jeep, but also in many light to medium-weight trucks and buses.

Stellantis engine

The 3.0-liter inline-6, called Hurricane turbo engine, developed in 2022 for use in Ram, Jeep, and Dodge vehicles, is unrelated to the original Willys Hurricane versions.