Speaking of Carbs

Hi all,
I have a question about a replacement carb for my Jeep. I did a search through the forum and considering my engine is a 76-odd fire buick 231 I don't know if the suggestions made for the 225 will work. I did a little research myself and found these two options from Holley

Model 2300
http://www.holley.com/HiOctn/ProdLine/Products/FMS/FMSC/0-7448.html

Model 4160
http://www.holley.com/HiOctn/ProdLine/Products/FMS/FMSC/0-8007.html

I am wondering if anyone out there has replaced the carb on their 231 with any luck.

Regards
-wannabe

 

Either should work with an adapter. I have the same motor about to go in and I'm planning on using an autolite 2100 from a late sixties mustang. Check the V6 References section for information on the four barrel carbs.

 

I had a 2300 on my 304 and hated it. It had a serious attitude problem. Went back to the stock Motorcraft 2100.

If I had to have a Holley, I'd probably pick the 2300 that's meant for the 302 Ford marine engine. 300CFM, side pivot float, probably spring damped needle, raised vents. Summit P/N HLY-0-80320-1

There are a few junkyard carb options, including the Autolite/Motorcraft 2-bbls and the Quadrajet 4-bbls.

 

I really appreciate the advice.
It looks like you guys convinced me to get the "original" (at least when I bought it) Rochester carb rebuilt. I thought I could do better in the aftermarket world, but it looks like no one likes any of em .

again the advice is much appreciated

 

Funny how things go. I've always heard good things about the Holly 2300. :? There a center hung float that should be impervious to off camber situations. I have Neptco's 2300 + adaptor that I bought from him and he was very satisified with it--till he went 4 bbl. I plan on using it if I dont like the rebuild of my 2G.

 

Jim, you're right - the center pivot float should be good in off-camber situations. The 2300 is targeted at flat track racers, where there are a lot of lateral Gs.

It's been a long time since I tried to make the 2300 work, and I've forgotten what my sources of info were. I do remember that the worst problem was uphill and downhill, at certain very specific angles. Much of this was cured by switching to a side-pivot float. Plus the bounce behavior was bad - big, low speed bounces would make it stall.

As I recall, you need to move the bowl vent higher (like on their Truck Dominator), baffle the jets, use a side-pivot bowl (like the Truck Dominator), and spring-load the needle. There may be other tricks too. To me, the marine carb looks closer to what you want.

In my case, the 500CFM 2300 gave me lots more pop on the street, but pooped out in the dirt. The 2100 was much better off road.

 

Tim: Guess What? Were Both Right! I can see the boal vent being extended, and Holly makes a baffle for the boal. You can also get spring loaded needles for it. But I think I would like the center pivot float better.

Now, my 2G works fine--thou a bit lean in the winter (it does get cold here in Havasu). The only thing that I've notice here is that on the Desert trails (hard packed dirt and rock) the "bounce/vibration" upsets it a bit and every once and a while you have to put the clutch in and "goose it" to get it to smothe out. No big deal, but all that "vibration" has a tendency to "upset" it. It's also hard on the float settings.

Like I said, I'll have the 2G professionally rebuilt--to check out the throttle shaft and butterflys. I'm at the high range of my jets and any richer are like hen's teeth. That's the advantage of a Holly--"Jet's-R-Us". R)

 

I've been around the 2GC caarb all my life and have never had problems with vibration causing it to spit and sputter. I've had them wear out and gain vacuum leaks and have dirt in them, but never the problems you describe on washboards/rough roads. I have usually set the flaot level a little lower than specs though, and even the drop is adjusted up a little, this might explain it. Back in the day a lot of guys I knew went to Holley carbs and had nothing but problems with them, but its possible the 2300 is better, I have no idea what they even look like. Usually professional rebuilds work pretty good, at least if it is one where they actually cehck shaft clearances and all that.

 

I may be a little late, but here is my 2 cents...
Up until my 231/cj5 project, all my carb experience was with q-jets...great carb if you take the time to learn it... never gave me problems off road in a 79 Blazer/454/th400/np205/36"swampers.
On my 1984 231 I used an aluminum open plenum intake with a Holley 390cfm carb, the 4160 model. Ran great on road with a little tweaking, but was horrible on hills. I added the front bowl baffle (have heard it refered to as a "whistle"), and made a crossover tube out of copper tubing ala the truck avenger. Lowered the float a frogs hair, and that was it--runs great off road, up and down hills. Plus some careful setting of the choke, mixture, secondary spring, ect. I also got a mesh vent for the rear bowl inlet but it required to add the metering plate to the rear, which I have heard is basically converting it to a 4150(?? don't quote me there). I didn't do that so didn't use the screen. Also I had trouble finding the spring loaded needle and seat, kept getting told they were discontinued. Since some of their new carbs use them they must be available, it just works so well I haven't bothered. Of course using a 4bubble would require a new manifold, I would think adapting a 4bbl to a 2bbl manifold pretty cheesy (not meaning to flame anyone this has worked for!!). I also run a 11"x5" k&n filter, outside the frame headers, and a msd ignition and wires thru the hei dist. The lower end is balanced and blueprinted. Running a rebalanced 225 flywheel for more lower end torque. with 4.88 gears and granny t18, I have 75:1 lowlow, and the warn overdrive lets me go fast enough that I quit before the jeep does.

 

Thanks for all the responses! But after attempting to get the carb rebuilt I found out that it is somewhat beyond a simple rebuild. The guy told me it was "missing parts" and "modified" so who knows what the PO had done to it. In any case, given I have a 2bbl manifold I will follow schardein's advice and go with a model 2300. Which leaves me with 2 more questions:

1) which cfm is best for onroad use? timgr had metioned that he was using a 500cfm, is that too much for the old 231 v6 without any aftermarket headers?

2) where would I find an adapter plate?

 

There is a 350CFM model 2300, Summit PN HLY-0-7448. http://www.summitracing.com/
For the adapter, I think it's TRD-2086 at Summit.