WANTED DISTRIBUTOR FOR 161 HENRY J OR WILLYS

[Terry T]

Looking for a functioning distributor for a 161; prefer F-head applicaton.

[Fid]

Do you know if the F-head and L-head are different? (I don't)
Also, if they are the same, do you prefer Delco or Autolite?  If it's for a Darrin, I'm pretty sure that one would be Delco. Joe Frazer likely knows for sure.  Either one would work.

[Terry T]

Thanks.
I do not know the difference between the two--maybe the advance curve.
This is for my 51HJ  powered with a 161 F-head.

[joefrazer]

The F-head Willys cars/trucks used the Autolite distributor while the L-head J and F-head Darrin used the Delco unit. Some Js also used Autolite distributors. The 6 cyl L-head Allstate I had used a Delco unit.

[Fid]

Thanks Jim. Did the F-head use the same distributor the L-heads used?  The 1951 and early 1952 Js used Autolite, the 1952-54 Js used Delco. I've heard the F-head works well in a J, I've never tried it myself.

[HJ-ETEX]

A lecture about HJ engines (1). The Willys/Jeep/HJ 134 4 cylinder started out in 1928 as the engine for the Willys Whippet. The intended market was the low priced segment which the Model T dominated. But just at that time Ford introduced the Model A, and the 134 wasn't particularly superior to Ford's new 4. Shortly, there was the Depression, Willys went into receivership and had to rely on their small cars to continue. So the 134 limped along. However in 1940, the military wanted a new small vehicle. This is quite a story in itself, but American Bantam came up with a design that was a winner - until Willys & Ford got copies of the blueprints through questionable means. Willys submitted a version using their 134 engine. The military gave Willys the contract and added Ford as a second supplier for insurance. Thus the fabled Willys MB and Ford GP came about (Ford made slightly more than 50% of the vehicles so the majority - by a hair - of the WWII 'Jeeps' were Fords. But to make an acceptable product, the 134 had to be improved, and Willys engineer Barney Roos put a lot of work into making the 134 as bullet proof as it could be.

[HJ-ETEX]

A lecture about HJ engines (2) Well, the 134 was typical of late 1920s engine design. It had a small bore and a long stroke although it wasn't as extreme as some. It had rather long connecting rods which resulted in a tall cylinder block. Immediately after WWII, Willys put Barney Roos to designing a new L head 6 cylinder engine. This was really -no PR bullsh*t- a new design, not just hanging 2 more cylinders on a 134. It had a much lower block and wasn't much heaver than the 134. And displacement wasn't much more either - it was only 148 cubic inches. And it looked a lot like the Studebaker Champion 6 which shouldn't be a surprise since Barney had designed that engine before he came to Willys. After a few years, this new 6 was punched out to 161 cubic inches which still put it at a disadvantage to Studebaker and Nash small 6s.

[HJ-ETEX]

A lecture about HJ engines (3) In order to get more power without going to a completely new design, Willys decided to convert the 134 and 161 to an F-head design. That is, the intake valve would be of an overhead valve type in a new cylinder head while the exhaust would remain in the block. You might wonder if they were going to design a new head, why not put both valves in the head? The problem was that these engines were small bore/long stroke. There wasn't enough room for both valves in the cylinder head. If only the intake was in the head, it could be much larger than the L-head and if the exhaust remained in the block, the existing block casting could be used with almost no changes.  The 134 L-head was already rather tall and adding some 4 inches more to make it a F-head caused problems. The hood on the L-head equipped Willys CJ-3A was raised 4 inches to make the bizarre looking F-head equipped CJ-3B.

[HJ-ETEX]

A lecture about HJ engines (4) This brings us to the subject of air cleaners. The L-head 134 was tall enough that it tended to be equipped with an offset air cleaner. In HJs, the air cleaner was mounted to the front and beside the engine like a scaled down air cleaner on a 51 Kaiser. On Jeep CJs, an oil bath air cleaner was mounted to the inside of the passenger fender and a flexible hose connected it to the top of the carb. The L-head 161 was enough lower that an oil bath air cleaner could sit on top of the carb.
I have heard of an F-head 134 replacing a L-head 134 in an Allstate, but there wasn't room for even an offset air cleaner.
And on a Darrin there actually isn't enough room between the carb and the hood on the F-head 161 so there is a thin mesh (keeps out birds and things larger) air cleaner with a rubber donut between the top of the air cleaner and the bottom of the hood.

[Fid]

The Henry J shop manual says to gap the points at .020 on the Autolite unit and .022 on the Delco.  I've tried gapping my '53 J, which has Delco, at .022 and it just doesn't work that well. I set it at .020 and it's fine.

[Terry T]

Thanks to all for the info.

[jeepbilt]

Terry,

If you are still looking for the 161 F-Head distributor, let me know.  I have a NOS one available to me.

George