F-Head Hop Ups

I'm posting some pictures Donny sent me. He'll follow up with explanations and his possible future plans.



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Thats exactly what this Jeep is! It was last run in the Naples Swamp Buggy races about 3 years back.
-Donny

 

A year or two ago, I pulled an engine out of another one of these race Jeeps that had thrown a rod. The racers turn these up to as much as 7000 rpm, and if you've ever heard an F134 screaming like that, you will never forget it. The local guys apply their own tricks to make these engines rev far higher than they were ever intended to. This particular engine had a seriously decked block where the piston crowns were well above the top of the block, requiring the pistons to be milled to fit into the combustion chamber. The intake valvetrain uses roller rockers. The side of the head was opened up for a side-breathing intake topped with a 4bbl carb.
This particular engine had the piston fail with the wrist pin pulling out, cascading into a broken crank, hole in the cylinder wall, bent pushrods, etc. The carnage happened around 6500 rpm on the race track.
The "Maybe Baby" Jeep is another race Jeep that was in running condition befor Hurricane Irma before last fall. The high winds broke a 4" pvc intake that allowed rain water into the engine. Later this week, I hope to strip the engine, trans,T/C, and axles from this.
My ultimate goal is to rebuild one of these race engines and get it on a dyno to see what the rear horsepower and torque figures are for an F-134, and maybe install it in a CJ3b of CJ5 to see how it actually performs on the street.
-Donny

 

That stuff is awesome...

That engine is asking for some forced induction!

 

So did you buy the whole rig? Or are you just getting some pieces?

I think I mentioned in another thread at one point, I made an adapter to run a 2bbl on a 134 with a head that was ported and decked just far enough that nothing was hitting (.125"). The increase in power from 2500 to 4000 rpm really was substantial, but the low-end torque was useless. It was great on the street; I just wished for a closer-ratio trans to be able to keep it in its sweet spot.

I can't wait to see what you come up with.

Also, do you know if there was a theory behind the size of the box that those carbs bolted to? My first instinct would tell me a tube with a constant size would work better? Or does the turbulence inside that vessel help atomize the fuel? Especially the view in pic #3.

 

Sorry for the long delay. The whole Jeep followed me home last Tuesday (May 9), free to a good home. My friend didn 't want to see it get crushed, and he got tired of flakes trying to buy it to put it back on the road.
I was hoping there would be some body panels worth saving, but the "body" is nothing more than an original skin welded to a tube frame, then sheeted with about 24 ga sheet. There is also some serious rust on the drivers frame near the original steering box mount. Fortunately, the body tube frame unbolts from the chassis. So I may save the otherwise solid chassis. The engine is the main item I am after. I haven't really tried to turn over, but it may be stuck from rainwater getting in the intake. The oil is clean, but haven't pulled the drainplug to see if water is in the bottom of the pan. The trans/TC was half full of clear water when I drained it. The axles may have some parts, but I'm not holding out much hope. Pulling off a the rear driveshaft showed a loose pinion bearing.
Right now, I need to get this thing broken down and out of the garage driveway.
Ryan, I don't know the theory of the large funnel boxes for the intake under the 4bbl carb, but I have seen several others of similar design. The stainless intake in photos 3 & 4 was "bench flowed" using a large vacuum pulling through the Carter AFB, with that one being the third or forth generation version. The test intakes are made from clear plexiglass to observe the atomization. It sounds like these engines don't like to idle under 1800 rpm, but that may be big cam.
Anyone need some custom Jeep wheels? Those are full-sized military NDT tires as required by the class rules, just compressed to about 2" wide.
-Donny

 

Bet we could get Stan to run those in Moab for a bit!!

 

Hmmm
Still need to get rid of that CJ3B frame I have hanging around, hmmm

What's the diameter ?