Steep Incline carburetion

I talked to a guy the other day that said he had to go to fuel injection in his jeep that runs a 360 AMC because according to him, his engine could not get
enough fuel on really steep inclines. He said he was running a four barrel, but I forgot to ask what carburetor it was. I was wondering if others here have experienced that, and if you think that steep inclines will be a problem for me running a 304 AMC engine with a 2 barrel MC 2100?

 

I run a 350 that is around 350/400 hp I have a 750 holley dbl pumper and start to have problems at around 45 degrees or so but it still runs.At about 60 degrees it floods out and stalls.I know its not a motorcraft carb but I hope this helps.

 

there may be a time or two it will give you a problem, but for the most part you will be ok . i run a v6 but it has a 2 barrel and i don't have to many problems just try it out if you don't like, try fuel injection . but it will cost you alot of money to do it .

 

I've got an edelbrock offroad carb made for this purpose mated to an edelbrock intake manifold, 4 barrel, on my AMC 360. Haven't had any stalls except for my clumsy clutch work. However I've heard you can setup any carb to similar specs with the right material/tools. I had to buy a carb for my rebuild so I went with the edelbrock offroad carb and haven't had any trouble since.

 

Almost guaranteed it was a Holley 4V.

The 2100 is a very good off-road carburetor - no worries.

 

I just put a rebuilt MC2100 on my 304. I was seriously considering one of the truck avengers because they are made for off road (crazy angles and such). I bit the bullet and put the 2v on and I'm glad I did. I took it to a new subdivision down the street to see if it would stall on a steep incline. I drove up to about a 45 deg angle and it idled perfect without a miss. I then put the 2 driver's side tires on the hill at about the same angle and no issue. Same with the passenger side. What I'm trying to say is: rest easy. That MC2100 is a great off road carb!

 

The 2100 floods horribly on very rough trails though, it doesn't handle bouncing well. It handles inclines and side slopes very well, but not a lot of rocking back and forth.

 

Jeep came out with a float damping spring to address hop-hop-flooding (for lack of a better term) in 1973. There was a service bulletin and an upgrade kit for '72s. If you have your original carb, the spring should be there on the float pivot. A few Jeep carbs I've looked at in junkyards have not had it, so I presume the rebuilders leave it off. My 2100 on my truck (from a 78ish Cherokee) has it, but I pulled the top cover to check before I bought it.

 

I bought an Edelbrock designed for just such a thing with my 258 and aftermarket 4 barrel intake. Works like a charm so far.

 

Tim,

Would I be able to locate that float dampening spring if mine is missing?

 

It had a Jeep PN, but today I'd expect you can only get it from a Jeep carb core. Not a complicated part - just a coil spring around the float pivot that unwinds to lift the float. Holley sells a spring dampened float or needle for the Truck Avenger that you might be able to adapt. Holley and MC carbs have a lot of similarities, both being made by Holley AFAIK.

A good part to look out for and hang on to though, if you see it.

 

We were told that about the stock carb in our 258. We have never had a problem with it at all, but have run into quite a few locals that have said that's happened.

We seem to be having some similar problem with our M-151 though right now and are ready to throw the carb as far as possible.

B

 

I have a holley 650 in mine and i have a bad problem with it flooding out on slight angles and when i hit bumps, anyone know a soultion that can help this prob B/C its annoying!!!

 

I pulled the top off of the carb today, and all I see on the float axle or pivot is a thin wire that keeps it from moving too far to either side. I guess I'd have to see a picture of that coil spring in order to figure out how to make one. Thanks for the heads up Tim. Lynn, thanks for the link, but I'm going to have to put TBI on the back burner for a couple of years while I finish some more higher priority upgrades. Doc

 

Sell the carb to someone with a hot rod and buy an offroad carb or fuel injection. Even with the offroad parts, standard Holley's don't work.

Barring that, lower the float levels, regulate the fuel pressure to about 2psi offroad, put in a lower vacuum power valve, add the offroad needles and seats, add whistle vents. Also, center hung floats work better than side hung. These will all help, but they won't solve the design issues that make Holleys such good race carbs.

 

One thing all carbeurators have in common is a float bowl. I even went through the trouble of re-shaping my own floats. What you want is a float that has less bouyancy towards the back. Sort of triangulated. And anything that keeps the float from bouncing is good too. You can have three good scenarios. 1st is you get lucky and the thing just never gives you troubles. 2nd, you spend the time and effort, and you do get it to perform great and you can temporily brag about it. Or 3rd, your carb really sucks off-road, but you don't see trails difficult enough to even realize it, and everything just seems peachy! I have been in all three categories, and now I run port injection.

 

I've searched thru all the Jeep books and manuals
they don't give us a pic of that spring in any of the exploded views
you'd think it would be shown somewhere from 1972 -1981

 

Hmm. It's about the size of a ballpoint pen spring, and goes over the float pivot rod. One tail from the spring goes under the float arm and the other presses against the side of the bowl. There should be a service bulletin from 1973... I remember putting these things on the shelf - little brown envelope with the spring and a piece of paper with the float setting instructions.

I have one on my carb, but it's a little inconvenient to pull the carb top and take a picture right now. It's real - I have one - the Jeep 2100s came with it.

 

oh I believe you Tim
from your description, the part number should be an early 812 xxxx then
I'll have to snoop some more
I've got the whole book of service bulletins.......somewhere....