MC2100 Alternative

[mriplaybass]

Since I have recently retired, I have decided to clean out (excavate??) the mess in our shop so that we can start in on our project vehicles, and enjoy life. The 79 CJ7 has been waiting patiently in the barn to have some upgrades done, and there is now enough room to put it back in the shop and let the fun begin!
"Chip" as we have named the most recent Jeep acquisition, since this is the 4th CJ we have acquired. (From the potato "chip" commercial: "Bet you can't eat just one", we can't keep from buying just one more.) Ran fine since we built it last spring. It has been parked in the barn most of the winter. When I went to start it up last week, I could not get even so much as a pop. Poured a little gas down the carb throat since, as I have posted before, the carb runs dry after a week or so, nothing. Gave it a little sniff of starting fluid, still nothing. Now the battery is getting low, so I put it on the charger over night. Next day, I checked for spark and had a good arc. More starting fluid, crank, crank, crank, still not so much as a bang through the intake. Maybe it didn't help that it was below zero, because the next day, when it was around +20° with a little starting fluid, we had ignition, and lift off!
Drove it into the shop and began trying to decipher why we are having so many starting problems. It did not take long to find the problem. Two of the four bolt lobes on the carb were broken! I don't know how this happened just sitting in the barn. Temperature swings? I have no idea how something which was properly torqued, broke so long after being torqued. It appears that the insulator/spacer under the carb deteriorated and crushed over time.

Now that I have vented, I will get to the real question (finally!) I will probably replace the carb either with another MC2100 or 2150 along with a new spacer (aluminum, OEM?). I'm pretty sure I remember the old one being a 1.08. Has anyone used either of these carbs from a Ford engine? How did it fit up? Is the bolt pattern the same as the Jeep version? And, what other carbs would be a direct fit to the stock AMC 304 manifold? Holley, Carter, etc.?

 

[CJim7]

You might also consider a Quadrajet. Small primaries, large secondaries, they are perfect for AMC V8's. I ran one on my 401 for several years before I went Propane and I loved it. Ran flawlessly.

 

[Posi]

I will probably replace the carb either with another MC2100 or 2150 along with a new spacer (aluminum, OEM?). I'm pretty sure I remember the old one being a 1.08. Has anyone used either of these carbs from a Ford engine? How did it fit up? Is the bolt pattern the same as the Jeep version? And, what other carbs would be a direct fit to the stock AMC 304 manifold? Holley, Carter, etc.?

Congratulations on your retirement!
The AMC 304 came from the factory with 1.08. Most of the 2150 came with 1.23, some with 1.08. I wouldn't recommend Holly unless it was the 470 truck avenger. Personally I would stay with the MC2100.
I have an extra mc2100 1.08 I can ship out to you.....call it a retirement gift.

 

[mriplaybass]

Congratulations on your retirement!
The AMC 304 came from the factory with 1.08. Most of the 2150 came with 1.23, some with 1.08. I wouldn't recommend Holly unless it was the 470 truck avenger. Personally I would stay with the MC2100.
I have an extra mc2100 1.08 I can ship out to you.....call it a retirement gift.

Thank you Posi! I think I just might take you up on that offer. I know, you just don't want to have to push or pull me this August!:ty:
I'll be in touch!

 

[007]

Hey congratulations!!!

I know you probably know what I'm going to say, but I would seriously consider an EFI solution. We both know how good carbs can be and how long they've been around and how good a job they have done and can do... I get it, I understand. For me though, if a guy has carb trouble and needs to do something - this is a no brainer if it can possibly be afforded. FITech and Holley both have units under $1000 with an enclosed ECM and include a single O2 sensor - completely transportable from this Jeep to your next .

As it stands now, I plan on keeping my CJ for another year at least and I'm definitely putting one of them on.

 

[mriplaybass]

Great news that you are planning on keeping your CJ, at least for awhile. My problem was not that the carb was not performing, it literally broke into 3 pieces, and the spacer under the carb kind of disintegrated. Got a rebuildable carb, (thanks Posi!), but still looking for a 1" spacer to go under it. I may at some point consider EFI. I have never heard of the brands you mentioned. $400 less than the Howe makes it a bit more tempting to just go with a boxed kit instead of converting a GM one myself. Right now I am staying with the OEM carb. Too many other upgrades that we want to do before wheeling season arrives, and it looks like that won't be too long! Might even try out some of the off road areas in your neighborhood.

 

[007]

Hey that would be awesome! Let me know and we will do it.

I imagine I'll keep my CJ regardless of a JK. Not the cheapest way but what the heck. It would be awful hard to part with it at this point.

Well good deal on the carb. I understand your thoughts on it. I think I'm doing a Holley Sniper this spring.


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[Posi]

but still looking for a 1" spacer to go under it.

Carburetor Insulator Plate V8 2BBL 1974-1991

 

[Lumpy Grits]

Congratulations on your retirement!
The AMC 304 came from the factory with 1.08. Most of the 2150 came with 1.23, some with 1.08. I wouldn't recommend Holly unless it was the 470 truck avenger. Personally I would stay with the MC2100.
I have an extra mc2100 1.08 I can ship out to you.....call it a retirement gift.

Very kind offer their Posi!
LG

 

[Posi]

Thanks LG, happy I was able to help.

 

[Hedgehog]

I just put a new spacer under my 2150. They are not plastic or metal, sort of a fiber glass like black stuff. I know you would like a metal one, but these things are supposed to reduce heat migration. Also remember, the old one did its job for 40 years. I didn't like the way the carb gasket and the spacer fir together. To much bind and not as flat as I wanted it to be. I opened up the holes and the interference areas, then used a sheet of sand paper glued to a board to flatten the surfaces. Worked very well.

The ears could fairly easily be welded back on your carb. It might save you a few bucks and you know the carb works.

 

[mriplaybass]

Hey that would be awesome! Let me know and we will do it.

I imagine I'll keep my CJ regardless of a JK. Not the cheapest way but what the heck. It would be awful hard to part with it at this point.

Well good deal on the carb. I understand your thoughts on it. I think I'm doing a Holley Sniper this spring.


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We hope to be back up and running sometime in May. Hopefully we can get together sometime after that.

Carburetor Insulator Plate V8 2BBL 1974-1991

Looks like exactly what I was looking for. Thanks Posi

I just put a new spacer under my 2150. They are not plastic or metal, sort of a fiber glass like black stuff. I know you would like a metal one, but these things are supposed to reduce heat migration. Also remember, the old one did its job for 40 years. I didn't like the way the carb gasket and the spacer fir together. To much bind and not as flat as I wanted it to be. I opened up the holes and the interference areas, then used a sheet of sand paper glued to a board to flatten the surfaces. Worked very well.

The ears could fairly easily be welded back on your carb. It might save you a few bucks and you know the carb works.

I am not positive, but I think this one is actually made of wood! It is brown, and has a grain like appearance to it. I have heard of wooden spacers for carbs, but thought someone was pulling my leg! I actually don't want a metal one if I can avoid it for the exact reason you sited, I followed Posi's link, and it looks like the one I want.
I probably will try to weld the ears back on the carb some time in the future and keep it as a spare. I can just see the carb cracking right next to the welds at the most inopportune time if I rely on that one being my only carb!

 

[Woolyworm]

I found a sweet aluminum adapter (4 to 2) for my 2100 for about $20 online - they are usually close to a $100! I had to drill and thread for a brake booster. I also run one of those 3/8" black fiber spacers. Mine seems to work well.

https://onedrive.live.com/redir?res...authkey=!AMpY14jyW2xW6u4&v=3&ithint=photo,JPG

https://onedrive.live.com/redir?res...authkey=!APEHCkKSB559cQk&v=3&ithint=photo,jpg


Wooly

 

[Hedgehog]

Mr. Bass - The one I installed is an odd material, possibly good old Bakelite. You will still need the 3/8" spacer. That is something different. It's a black fiberglass/bakelite type material with a black material sprayed on top. I found this out when trying to improve the way they fit together.

 

[Turbogus]

I remeber the Carter AFB Thermoquad that used a Phenolic (as opposed to Phrenolic) material as the throttle body, perhaps it's the same stuff that spacer is made out of.

 

[mriplaybass]

What ever it is, it is going to be replaced with good old plastic. I think the plastic spacer will provide better insulation against heat than an aluminum one would. I remember the bakelite. Always had to be careful not to break it. I did ordered the 3/8" gasket.
My wife was looking up spacers a few weeks ago, and did find some threads, I think on other sites, where people were making the spacers out of maple. Although I am an avid do it yourselfer, this time I think I will just buy the part instead of spending hours making one myself. All the parts are on their way, including an electric choke conversion. Sure will be nice not having to remember to push the choke knob in all the time!

 

[Lumpy Grits]

I have made carb spacers from the plastic cutting boards you can by at Wal-Mart.
LG

 

[Hedgehog]

I've made the mistake of setting a hot pan on one of those boards ... ..... believe me they are not heat resistant. Seems like a bad choice for a hot environment like an engine. But a very neat choice for dozens of other projects.

Mr. Bass - Phenolic material, that's what the stock spacer is made of. Likely that is what your going to get. Looks for all the world like plastic. As far as the fit issues I wrote about you will see what I meant when your parts arrive. More than likely they don't really NEED fitting, but it felt like the right thing to do to me.

 

[Lumpy Grits]

Don't know what the white solid plastic ones are made of. Never had an issue with one.
LG

 

[Posi]

Bass, I was in my parts loft looking for a distributor vacuum advance when I came across these . Wish I had of looked before sending out your package.