More Power from an F-Head

I am considering rebuilding my f-head over christmas break this year. while i'm at it it would be nice to upgrade enine components to stronger and lighter materials. what kind of new replacement parts would you guys recomend when i do this? it would be nice to get a little more horsepower out of the engine too. i was thinking aluminun pistons, piston rods, new exhaust manifold etc.?

 

You're limited by the bore/stroke of the stock engine. You can try and raise compression and make it breathe a little better with a header, but you won't gain alot. It won't rev high cause it's a long stroke motor, doesn't make any more power when you wind it up. I think you're stuck with stock rods, they're plenty beefy from the factory. Don't expect more from it than what it was designed for and it'll last another 50 years.

 

header is more trouble than its worth... HP gain might be like 2-3 horsepower (if it doesnt leak)... you wont even feel it. If you need more power you really need to do a complete engine swap.

 

You already have forged steel rods and crank, so no upgrade possible or needed there. I'd say your best option if you keep the 134 is turbo or super charging. The stock engine has the strength to handle boost. Otherwise go stock or plan for a swap.

 

Back in my youth when they used to have Jeep races in N. California, one of the fellows who ran in the four banger class had his engine completely blue printed and balanced, don't know if it boosted his HP any, but it sure ran nice and smooth without any vibration.

 

I had mine balanced, ported, 3 angle valve job and the cam timing advanced. On paper this bumped it up to about 81hp. I also got rid of the oil bath and went with a pleated filter. Leaving tomorrow to get some headers made for it.
It runs like a striped assed ape. Well a small monkey anyway.

Was it worth it? To me it was, I wanted as much as I could get out of it and still keep it somewhat stock. It all comes down to what you want and what your going to use it for. And how deep your pockets are.

Somewhat stock ... is that like sorta pregnate?

 

My dad used to jeep race in the late 50s early 60s in southern NM. This pic is probably about '65. He is the co-pilot. The pilot in the pic offered me a chrome moly crank that he had laying around, unfortunatly he offered about 2 months after I had the engine built.

 

Thanks for the imput guys. Yea my pockets are kinda shallow right now if you wanna say that. I'm a student in Boston but live in Ct so I cant do to much to make money. I like the idea of replacing the oil bath with a nice filter, that should let it suck in ait much easier. I would like to get headers built eventually also. About how much would custom headers like that cost? and whats the largest diameter pipes that they could be made with? I would like them to be the biggest possible but still be able to fit comfortably in the eng. compartment.

 

Best thing from what I've been gathering is, keep the factory manifold and go with the Solex carb.. I'm planning on adding a turbo. Gonna get stuff from junkyard and fabricate as needed. I'll start a worklog once I get started, right now I'm gathering intell. my .02cents

 

You can also clean up the inside of your exhaust ports and exhaust manifold with a Dremel tool. Look in there for rough areas, and smooth 'em up some. Intake ports too. Every little bit helps, just don't go overboard. And I wouldn't recommend doing this with the head on the motor!

Just remember F-heads are basically glorified tractor or industrial type engines and they're designed for low rpm/high torque. Ain't made to go fast, made to work hard and last.

 

I know the turbo has been an issue that has been poping up alot recently, has anyone used a certain turbo? what about intercooler? The whistle of a supercharger would throw ppl off

 

I have been trying to get a old tubo unit off our small Kubota diesel engines we use in our mowers. No luck yet but I may have one soon. These engines vary from 35hp to 60hp so I think they would work for something like the f-head. Look around golf courses for old equipment out back and talk to the superintendant if they have any. May be a cheap way to get a turbo.

 

Good idea on porting the exhaust but I'd leave the intake rough so it helps keep the fuel suspended in the air. I read this in a hot rod magazine before.

 

I agree. I didn't mean polishing the intakes, just knocking down any casting flash, lumps, etc. Rough surface helps with atomization, but I'm just talking about little restrictions and airflow disturbers.

Although I had some P&P heads on a Harley once, and it liked them!

 

Could always get "the tornado" haha

 

When I switched to the K&N air filter, it breathed tons better! So much that I had to tune the idle back down and mixture settings. I picked up about 3-5 mph on the open road and it idled sweet! I dont think the 4-bangers need much more!

 

From what I've read (I'm not an expert on this by any means) turbos are matched to the operational range (in RPM) of the specific engine. If you put a big turbo on a small engine, you get too much boost at "high" RPMs, but you may get the boost you want at lower RPMs. Most passenger cars need/use boost at RPMs that are excessively high for the F134, so you may want to use a turbo from a much larger engine on the F134 than you would expect. The Kubota turbo may be ok (though I suspect it's undersized) but you could also probably use a turbo from a LeBaron with a V6 or such.

Dcik Datson's site has a lot of good info on homwbrew turbos and superchargers http://www.studebakerclubs.com/21stCenturyTurbo/TheIndex.htm
I have a couple of his books (out of print AFAIK) about Jeep engines that are chock full of good stuff - a collection of his old newsletters, so very disorganized, but good stuff.