Weber 38/38 carburetor conversion on 230 engine.

Hey if anyone wants to convert to a good quality two barrel carburetor this is what i did for my jeep. I created instructions and a parts list for the conversion. Feel free to reach out to me with questions and/or further information. EDIT: MORE INFORMATION AND UPDATES IN THE COMMENTS!

230 tornado, weber 38/38 conversion.
Parts:

Two barrel intake + nessisary parts(intake gasket, harware, and nessisary parts for the thermostat)

Motorcraft to weber carburetor adapter, you may need the gaskets
99044.015

Weber carburetor: #18930.086 / #18930.020 ~
~(I used the type 38 DGMS #18930.086 so if you use the other option #18930.020 you will need to figure out the 12v set up for electric choke. These instructions will work for both, just ignore the parts involving choke)


Weber to Suzuki Samurai air filter adapter #99010.600 (this is if you plan to use the hood mounted air filter)

Retain the old chamfered air filter gasket

Linkage kit parts for weber carburetor
#99007.116

1-5psi fuel pressure regulator, i used holley brand #12-804

7 mm spacer for weber carburetor

Paper or cork gaskets for weber 38/38

Nessisary length hoses 5/16 is what i used. Sorry i didn't write down how much i used.

May need new/longer choke cable if you decide to not use the electric choke version

Adequate length 5/16" hoses

M6x1.0 4 inch stud and harware.

If not all ready installed you will need the hood mount canister air filter and the parts that accompany the kit. The zone containes a parts list you will not need the parts for the governor. This conversion does not provide for the stock carb mounted air filter, if you do not want to use the hood mounted air filter there are plenty of universal options to choose from

Please note I probably did not call out small parts and fittings because i dont remember what ones I got/needed.

Drain engine block of coolant, Remove old carburetor and intake, retain everything nessisary for the remounting of new intake, I replaced my studs and hardware on mine but you may not need to. You will be reusing your old throttle cable if you want to, at this time i have not attempted to changed to a universal throttle cable.

*note: not every two barrel intake is 100% the same, you may need to drill and tap new ports for the crank pvc and thermostat sending unit*

Install new intake gasket and install two barrel intake and torque to spec. Refer to TM for specs.
Install the adapters gasket and adapter plate in correct orientation there is no torque spec so "tight"

Make sure you have the correct throttle connection plate on your carburetor to connect stock cable. If you are reusing the original cable like I did you will need to drill out the cable bracket hole to fit.

Cap off all the vacuum ports on the carburetor if you decide to not use them. You will need to drill a hole in the air filter horn inline to the stud hole on the adapter, if you are not confident with drilling a hole true and centered, my local machine shop charged me $30 to due it for me. Install carburetor onto intake. Install the air filter adapter onto the carburetor using supplied harware, and then the air horn using the 4 in. stud. The air horn will fit and you should be able to use the old gasket. DO NOT OVER TIGHTEN THE STUD. The stud will break the adapter, tighten enough to not be able move the air horn is tight enough. Edit: The original Air Duct for the carburetor air horn to the air filter May not work. The original duct was too stiff and un flexable for the adaper and i kept breaking them. Mine was NOS so if you have an old broke in one it may work better. The new carb sit more forward then the old stock one and the angle is to much for it to bend. I went to my local Napa and got a generic 3 inch air duct hose, about 2 feet worth. And replaced it. Now its thin and easy to pop a hole in but works great so far untill a new alternative pops up

Install fuel filter regulator someplace where its not in the way, I chose the inner fender below the horn and harness. The low psi Holley regulator has two out ports I used one to install a fuel pressure Guage and the other was the out to the carb.

You will need to orient the hoses and cables to fit but they will fit. Tune the weber to work. You May need to rejet your carb for your application. So far I will need to rejet the 18930.086 carbs idle jets similar to what is in the 18930.020. For any tuning or other resources the 232/258 AMC Jeep motors has the most support.

I did not have a canister style filter so I bought a NOS kit from saturn surplus.
The reason i decided to go this route was because i was faced with a problem that was slowly growing bigger; first being that i had to special order my old style air filter element because none of my local auto parts stores had any instock, napa, carquest, O'Reillys, autozone. Then i started rebuilding my carburetor and a quality kit was $60 and that wasnt bad but my carb was cracked in the bowl and i decided it wasnt worth doing twice. I wanted to retain as much of the originalness of my truck as i could. The Motorcraft 2100 is a good carb but you cant get a new one any more, only the knock offs and rebuilds, and the Holley 2 barrels was also a good option but Holleys are designed for "faster" applications, which this Jeep and motor is not even in the same solar system. That didnt leave alot of options, Redline Weber was, and still is, a well known carburetor known for their ability to proform well on road and off road, still with oem support and straight forward design that allowed for vast modification to work with our engine and application, made this a great candidate for my idea. I had a 32/36 on my old postal jeep and it was a night and day difference.

I decided screw it and do it. Searching on the various groups and the Zone, even the old forums, I didnt find anything directly helpful with what i wanted. I wanted to keep as much of the military aspect and originally as possible. So far it work. If anyone has any questions or needs further information or clarification feel free to ask! Also I'm tossing around ideas for a a 32/36 conversion using the original one barrel intake if any one would like to help.

This is a fantastic writeup and conversion you have done! As the old parts get harder to find, this is great info...wish I had known...I have a canister type air cleaner setup sitting in the shop I would have gotten to you cheap for this...if anyone else is considering it, let me know.

I have this question...as far as the cfm of the weber, do you know what it is? If not, how close are the sizes of the throttle plates on the carb to the openings in the manifold top? Obviously trying to get a handle on size...the factory Holley 2300 and 2415 carbs are 350 cfm...and the throttle plates on those are very close to the hole size in the manifold.

Hats off to you...great write up with pics and documentation....excellent work Sir!

Thank you very much. As for the cfm on a weber it varies due to how customizable webers are. Infact weber actually said that their carbs dont put out more then the engine can pull, and that it all comes down to the matter of tuning. I want to say the 38/38 i got was close to about 350-450 cfm which is very close to cfm range to a Motorcraft 2100 or the holley 2300. If you have the know how you can change the idle jets, the main jets, the acceleration jets and the emulsion tubes to run how ever you like. Right now im playing with the idle jets for mine because it idles with too much fuel. But with the weather itll be a good minute for me to sort it out. The other option for weber carburetor i put up there, the 18930.020, is jetted better for a 232/258 amc motor but it doesnt have factory manual choke or anti stall system installed. I knew this specific carb may of been to much for the engine but i was hoping to challenge my self on re tuning it to fit.

Im also going to say that ive rewrote these instructions 5 times and each time i read threw this i realized i for got a part or a set or some other small piece i needed to call out. Im not used to writing out instructions either and i probably wrote this in a way that made sense to me so if there is any confusion or questions please feel to message me or comment on this post.

Fantastic work!
Can't wait for a road test report.

I cant wait to give one. Once it fired up i drove it around the block and found the alternator or regulator has Something wrong with it, and the brakes need work. Also having trouble tracking down the correct jets.

Hey all i got her running and fired up. The stock jets may be to large for most applications i ended up moving to size 40 idle jets and 130 mains. The acceleration jets i have not touched yet because shes not driving around yet. My alternator ended up violently dieing on me. Go figure.

The carburetor requires two different idle jet type, but the size is the same, just an overall different shape. The part numbers i used is: 74409.040 & 74403.040. You need one of each and to get bigger or smaller simply change the last two digits. The main is 7380.130 and you will need two.

Great information. I always appreciate it when someone takes the time to do something like this. It helps others big time. Thank you!

I wish I had your insight when I ran a Weber on my cj7 a long while back

Hey everyone. I did some more tuning and playing around with the weber since the weather has improved. I had to replace the the acceleration jet for a smaller size and i decided to plumb in the fuel return line. I needed about 14 feet of 1/4 fuel line and i tied in a cutoff valve. I used a small brass bulk head fitting thats has female pipe thread and carefully drilled a hole in the gas tank and bought some nylon gaskets and secured the fitting next to the fuel inlet as high up as i can to the top of the tank.. be extremely careful if you decide to do this your self. There is also the option of just blocking the line on the carb but then you'll need to ensure your fuel pressure is correct.
When you replace your acceleration jet you need to also replace the copper gaskets that go on top and bottom of the jet. Weber recommends .05 up from your idle size . So if you have .40 idle jets then you'd need .45 acceleration jets ect.

ACCELERATOR PUMP JETS
76215.045
PUMP JET GASKET
41540.014 2 needed

Its been a minute since ive been back here to give an update. I had to play around with the jetting and tuning some more to feel like ive zeroed in on it. Im still mildly rich but im going to do the adaptation for spark plug wires and throw in some hotter civilian plugs And recheck. The carburetor works great! The only issue i cant get figured out, yet, is the pcv valve plumbing, id like it to go before the carb but i might need to pumb it into the air filter. I will probably invest in a universal throttle cable to make the gas pedal less stiff. This jeep starts up with minimal choke needed with this new carb! It idles clean and accelerates clean. It also eats less gas then the old single barrel holley. Haven't figured out how much since my fuel gauge is finicky. Some of you may experience vapor lock issues during the hottest time of the year, i did, that was frustrating and i had to move some of my fuel line plumbing around but got it sorted out. Again my inbox is open to any questions or help, same with the comments!