Main >> Engine >> Factory >> Willys 134 I4 F-Head

The F-Head 134 inline 4 was the standard engine in the CJ-5 and CJ-6 from their introduction until 1971. The F-Head was the only engine ever used in the CJ-3B. The engine also saw action in starting in the middle of 1950 in Willys Wagons and Willys Pickups. It was also used in FC trucks.

The F-Head 134 uses a cast iron block and head with mechanical lifters, 3 main bearings, and forged steel crank and rods. Two versions of the F-Head were available most years, the output specifications are the same for both, the compression is different. The intake valves are in the head, but the exhaust valves are in the block. The valve configuration makes the F-Head engine taller than the L-Head because the L-Head has the intake and exhaust valves in the block.

New engine compartments had to be designed to make room for the taller engine. The CJ-5 and CJ-3B were designed with this engine in mind. It is fairly common to see a F-Head engine swapped into a CJ-2A or CJ-3A. Normally a section of the hood is cut out to make room for the carburetor.

There is a lot of confusion about the name of the F-Head engine. The F represents the valve configuration where one set of valves is in the head and one is in the block. The "F" in F-Head does not stand for "Flat" nor does it stand for "Ford". Other makes of vehicles used flat head engines and some people think the F-Head stands for flat head. Another source of confusion is Ford built some of their WWII GPWs with bolts with an "F" on the head so the parts could be distinguished from the Willys MB. They used F head bolts to build the GPW, but this is not related to the F-Head engine.

 

The main difference between different versions of the F-Head engine is the compression. The early F-Heads used between '50-'60 in Willys Wagons, Willys Pickups, CJ-5s, CJ-3B, etc had a low compression F-Head standard. The Willys Pickup only used this engine from '50-'56 and in '59.

 

 

Hurricane F-Head 134 I4
Bore x Stroke	3.125" x 4.375"
Displacement	134.2 (2.199L)
Compression Ratio	6.9:1
Horsepower (gross)	72@4000rpm
Torque (gross)	114@2000
Main Bearings	3
Valve Configuration	F-head
Fuel	1-bbl Carter

 

The "High Altitude" option was the same engine with a higher compression ratio.

 

Hurricane F-Head 134 I4
Bore x Stroke	3.125" x 4.375"
Displacement	134.2 (2.199L)
Compression Ratio	7.4:1
Horsepower (gross)	72@4000rpm
Torque (gross)	114@2000
Main Bearings	3
Valve Configuration	F-head
Fuel	1-bbl Carter

 

 

Between 1961 and 1970, the high compression version became standard and the low compression version was optional. A slight horse power gain was realized. The Willys Pickup used the 7.4:1 compression engine as standard and a 7.8:1 compression engine as optional from '60-'62.

 

Hurricane F-Head 134 I4
Bore x Stroke	3.125" x 4.375"
Displacement	134.2 (2.199L)
Compression Ratio	7.4:1
Horsepower (gross)	75@4000rpm
Torque (gross)	114@2000
Main Bearings	3
Valve Configuration	F-head
Fuel	1-bbl downdraft

 

The optional low compression F-Head used from '61 until '70.

 

Hurricane F-Head 134 I4
Bore x Stroke	3.125" x 4.375"
Displacement	134.2 (2.199L)
Compression Ratio	6.9:1
Horsepower (gross)	75@4000rpm
Torque (gross)	114@2000
Main Bearings	3
Valve Configuration	F-head
Fuel	1-bbl downdraft

 

In 1971, a low compression version was the only one available in the 49 state version. A California version was high compression.

 

Hurricane F-Head 134 I4
Bore x Stroke	3.125" x 4.375"
Displacement	134.2 (2.199L)
Compression Ratio	6.7:1
Horsepower (gross)	75@4000rpm
Torque (gross)	114@2000
Main Bearings	3
Valve Configuration	F-head
Fuel	1-bbl downdraft

 

The California high compression F-Head available in 1971.

 

Hurricane F-Head 134 I4
Bore x Stroke	3.125" x 4.375"
Displacement	134.2 (2.199L)
Compression Ratio	7.4:1
Horsepower (gross)	75@4000rpm
Torque (gross)	114@2000
Main Bearings	3
Valve Configuration	F-head
Fuel	1-bbl downdraft

 

 

 

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