Dyno results! Aftermarket Aluminum 8-1 head mod With Video!

[Frank]

Thanks for the info Marty
I bought a Chuchua head in Oregon that will be shipped soon. I am SO looking fwd to test that head in one of the jeeps
Do you know any source for better exhaust and intake manifolds? I saw a picture a few years back of a Willys engine with headers and duel carbs.

Cheers,
Frank..

[lt.luke]

Clifford Performance may make something. They do a lot of inline 6 parts.

[Marty, SoCal]

Frank,

Maybe you could make your own custom intake manifold to fit a couple small Volvo B1800 side draft SU's?

I read somewhere that a common mod was to take a stock intake, put a freeze plug in the 1 barrel opening, flip it upside down and machine out the bottom for a two barrel carb with an adapter plate. The modified intake would then be fitted upside down on the block. A 32-36 DGEV series Weber carb would work pretty well.

Bosch W8AC VW plugs should work as well as the Autolite 425s, and might be easier to get in Norway.

An exhaust manifold off an "F" head 134 will flow well, and not have the intake preheat feature of the stock "L" head exhaust manifold. A 50mm/2" exhaust system and high flow muffler would flow much better than the stock Pea-Shooter exhaust, too.

I don't think Clifford research makes the L134 headers anymore. A fabricator could make a set pretty easily, though.

I used 7/16", USS coarse thread grade 8 bolts, 3" long with 7/16" SAE grade 8 washers to replace the stock 2-3/4" long bolts. The head is a little bit thicker than a stock iron head, that along with the washers and corroded old bolts I had required longer replacements. Studs 1/4" longer than stock would work, too.

Use a postwar "Geardrive" type head gasket. It matches the combustion chamber shape better.

[Frank]

Again THANKS Marty.
I will have to wait with the plugs till I have the top here in my hands, but finding plugs will not be a problem. I was hoping that someone had made an intake with to seperate "barrels" for the carbs and had tested out the correct lenght etc, but I might end up with making it myself. Any tip of what I should not do when I start on that prossess?
Carbs from a Volvo was a good idea They are easy to find, but I have no experiance with them, eccept for driving them now and then.
F head exhaust manifold should be possible to find.
Frank..

[tamnalan]

Marty - you still running this head? What's been your long-term impression?

Just curious.

Thanks much

[Marty, SoCal]

Yep, still on the jeep. Haven't driven it much lately, though. Well worth it, due to the extra power and better gas mileage it provides! I may paint it OD to hide the mod a bit better, though!

[Jeff Gordon]

The combustion chamber shape in the aluminum head is different from the WW2 head, but almost the same as the ribbed CJ-2a head I pulled off, just with a perfectly flat and shallower roof. The CJ-2a head had better power than the WW2 "F" head I had on before, especially noticable at the upper end. I assume the wider combustion chamber over the cylinder bore allows for better flow. The power increase with the Hickey or Chuchua aluminum head is probably mostly from the raised compression. A CJ-2 head would probably need about 1/8" milled off it to get the same compression ratio, as that is about the difference in the depth of the chambers. I'm not sure if the iron head could handle this much of a milling.

So for those of us not lucky enough to get our hands on a Chuchua head a CJ-2a head shaved would be our best option.
I might give it a try.
Thanks for sharing.
Cheers
Jeff

[tamnalan]

This mod sure has me interested. I want to pull a trailer often, and the extra horsepower would come in handy.

[TailSlide]

Kaiser Supersonic head, Burns dual carb intake, Solex carbs, Clifford Performance header, Pertronix ingnition. Never dyno tested it but it is perky.





A friend of mine made up a nice airbox to connect the dual carbs to the stock filter.