Build Thread I'm making progress on my project 79 CJ

[polish85]

Thought I should probably update my build thread since a lot of changes have already been in the works since I "finished" the CJ.

I recently installed a stainless twin stick shifter for the Dana 20 Transfer Case after getting frustrated one time too many with trying to shift in and out of 4wd. The new shifters work great!

I decided I wanted to squeeze more horse power out of the 1979 AMC 258 i6 / 4.2l six banger after all this time of losing mph on long highway uphills so I started collecting parts for the popular 4.0 head swap project. I found a 1995 Cherokee at the local pick-n-pull with a high output #7120 head casting still in it. I purchased the head and the aluminum valve cover for only $50. It's going to the machine shop this afternoon for a valve job and resurface. For the exhaust I ordered a brand new 4.0 Cherokee manifold for only $72 including shipping from an ebay seller. For the intake side, I decided I want to stick with a carburetor instead of all the mess of installing fuel injection. Since my stock cast iron one barrel intake will not work on the 4.0 H.O. head, I ordered a later model AMC 258 i6 / 4.2l two barrel aluminum intake from ebay that will work with the new head after a couple minor mods. That just leaves the caruretor to deal with. Since my trusty freshly rebuilt one barrel YF carb will not work on the two barrel intake, I decided to go with a Motorcraft MC2150 carb and a Mr. Gasket #1937 adapter plate. A fellow Jeep-CJ forum member offered to sell me one that he has laying around that will require a rebuild, but is priced about the same as what I would pay at pick-n-pull for a rebuildable core. I might as well save myself the trouble of stomping through the slush at the bone yard and send a little money to a fellow Jeeper while I'm at it!

I'll follow this up with pics and details of how the swap goes as I make progress.

The jeep looks great!!! Take some good pictures of the swap if you could...i plan on doing it in the next month or 2 and pictures would really simplify the process and im sure other will like it 2!

 

[Rescue Diver]

The jeep looks great!!! Take some good pictures of the swap if you could...i plan on doing it in the next month or 2 and pictures would really simplify the process and im sure other will like it 2!

Thanks!

The machine shop just called and the head is ready to be picked up. They said the guides are in great shape, and all it needed was to freshen up the the valves and seats, and new seals. Not bad for a head that has over 200k miles on it. The exhaust manifold, carb adapter and new 10" Edelbrock air breather are out for delivery today. The 2150 carb is shipping out in the next day or two. If all goes well, I should be doing the swap next weekend. I'll take plenty of pics.

 

[Rescue Diver]

Everythin is here now except a couple gaskets, the intake and the carb. I bench fitted the exhaust manifold and it lines up great. Here's the first round of pics.

 

[polish85]

Everythin is here now except a couple gaskets, the intake and the carb. I bench fitted the exhaust manifold and it lines up great. Here's the first round of pics.

Looks good. Nice headers there! This is going to be such a nice jeep! Wanna trade?

 

[Rescue Diver]

Looks good. Nice headers there! This is going to be such a nice jeep! Wanna trade?

That's actually just a stock replacement for a 1995 Cherokee manifold. It was only $72 new including shipping from an ebay seller, and it even came with a gasket, the donut, and the flange bolts.

I just wish I hadn't already wasted $140 a few months ago on a new cast iron manifold for my original AMC 258 i6 / 4.2l head. I had no idea at the time that I would be doing this head swap upgrade so soon.

 

[Rescue Diver]

I was planning to make a little more progress this weekend besides cleaning and painting the valve cover, but thanks to FEDEX and USPS, I didn't. My carb was scheduled for delivery yesterday via USPS and the Intake Manifold was out for delivery via FEDEX. Neither arrived. USPS claims they attempted delivery at 6:37pm and that a notice was left. I was home and they did not show up or leave a notice. Fedex says a delivery attempt was made but failed due to weather. They changed the tracking status to "Not Delivered Due to Weather". It's been 4 days since we had any snow, and my driveway and porch are completely clear and dry. To make things worse, FEDEX doesn't do residential delivery on Monday in my area, so it'll be Tuesday before they can deliver it.

Sorry, had to vent a little. It's really frustrating waiting all day for a delivery that never shows up, waiting for two deliveries that never arrive is a lot worse!

 

[Petescj]

carb show up today???

 

[Rescue Diver]

carb show up today???

Adventures with the US Postal Service. They sheduled it for delivery Saturday but never showed up. They updated tracking to say they attempted delivery and left a notice, but they didn't. We were home the whole time. I then went on the USPS web site and checked the box saying "customer will pick up". After work I went by the post office with the print out from USPS that included the reference number for the missed delivery, waited in line for 20 minutes to hear them say they couldn't find it. Then they asked for the original tracking number. I thought it was on the print out sheet but it wasn't. So I went back home to get the tracking number, went back to the post office and waited in line for 30 minutes this time only to hear them say they had no idea where it was, and that we have a new carrier on our rout. Just now I saw the mail truck driving by, so I flagged her down and asked if my package was somewhere in the truck. I couldn't believe it when she looked around and said, is this it? It shouldn't have still been on the truck, or loaded back on it after I selected customer pickup on the web site the other day, but apparently it was still sitting somewhere in the back when the truck was parked Saturday night. She seemed surprised to see it there, so I'm guessing if I hadn't caught her at the curb, it would still be riding around town.

So yes, I got it, and it looks great! I already have a rebuild kit for it, but after the day I had at work, and the fun with the USPS, I'm thinking I'll wait till tomorrow to work on it.

Thanks again!

 

[Petescj]

Wow! Glad you flagged it down but safe to say I wont use Usps again. Used to be the way to go for the smaller stuff. Well guess you can take a day off. Just make sure its only 1. I need stuff to read .

 

[Rescue Diver]

Wow! Glad you flagged it down but safe to say I wont use Usps again. Used to be the way to go for the smaller stuff. Well guess you can take a day off. Just make sure its only 1. I need stuff to read .

Carb Update. I identified the carb. It's actually an MC 2100 not a 2150. That's better for me because it's a more simple design that goes better with my keep it simple theme. It's an early 70's one, possibly from a 71-74 ford F100 truck with a 302. I went ahead and bought another kit that matches it, so all the gaskets are correct. I decided to take a few minutes out of what was left of my evening and dissassembled it and left the parts soaking in carb cleaner. The intake is again out for delivery with Fedex. Hopefully I'll have all the parts I need to do the job by the end of today. The only thing I'm missing is bio degradable packing peanuts that disolve in water to use as backing when I fill the extra water ports in the head with JB Weld. I'll get them at office max on my way home today.

 

[Petescj]

I was told by a few different people that the 2150 had no port on the rear of the carb and was the easiest identifying factor. Hmm. this means that what I have on the Scrambler should be an earlier Mc2100?

Carb Update. I identified the carb. It's actually an MC 2100 not a 2150. That's better for me.

 

[Rescue Diver]

It's definitely a 2100. I checked a bunch of web sites and there's no doubt. Not to mention the gaskets in the kit I bought for a 2150 were no where close. The 2100 kit matches it perfectly. Like I said before, I'm good with it!

One other thing I learned is that some times they'll run rich because they're prone to leak gas through the threads of the power valve. That might have been why it ran too rich for you. The fix is using a little lock tight thread sealer on the power valve threads. The jets are already only 48's. I ordered a set of 47 jets so I can experiment.

I was told by a few different people that the 2150 had no port on the rear of the carb and was the easiest identifying factor. Hmm. this means that what I have on the Scrambler should be an earlier Mc2100?

 

[Petescj]

Thanx for the info.

 

[dalefan88]

i got 46 jets in mine and it runs pretty good. i wanted 47 but they where out of them when i got the jets.

 

[Rescue Diver]

i got 46 jets in mine and it runs pretty good. i wanted 47 but they where out of them when i got the jets.

What venturi size is your carb? Mine is a 1.14". Most people recomend 47 jets for the 1.08" on a AMC 258 i6 / 4.2l , but I haven't run across any recomendations for the 1.14". The differnce in CFMs between the two isn't much. The 1.08 is 287 CFM's and the 1.14 is 300 CFM's so the jets should be just slightly bigger on a 1.14.

From what I've read, my 1.14 was supposed to originally come with size 50 jets but it has size 48 now, and they look like they've been in there a long time. The previous owner, PetesCJ said it ran rich on his CJ8 , so just to be safe, I ordered a set of 47 jets. Who knows, after I rebuild it, replace the power valve with the correct one for my engine's vaccum, and take care of all the little leaks that I've read about, it might run just fine with the 48's. The great thing about these carbs is that you can swap jets easily by just removing the four air horn screws and removing it while it's still all hooked up on to the engine. I plan to have my buddy at the exhaust shop weld a bung into the pipe so I can temporarily install an O2 sensor and use the wide ban on it to set the mixture exactly where I want it.

 

[Rescue Diver]

Last night I thoroughly cleaned every part of the MC 2100 carb. There's not a speck of carbon or rust on any part of it or in any passage. Tonight I'll be assembling it. I still need to clean and strip the intake, find brass fittings at Ace Hardware for all the open ports and file a couple notches on the under side of the intake to sit on top of the alignment dowels on the head. I'm still on track for doing the head swap this weekend.


P.S. Pete, I love this MC2100! It only has one vaccum line, and it's the one that only has vaccum under throttle. That's all I need for my vaccum advance. Simple is always best! I'll run the power brakes and PCV off a port in the intake, just like I now have it with the old setup.

 

[Petescj]

Pete, I love this MC2100! It only has one vaccum line, and it's the one that only has vaccum under throttle. That's all I need for my vaccum advance. Simple is always best! I'll run the power brakes and PCV off a port in the intake, just like I now have it with the old setup.

Glad it works for you. I tried rebuilding a Weber before and didnt have good results. Thats the same model as the rebuilt Mc2100 I bought. One port on the passenger side that I used for the Vaccum advance. Alot of people think you need the large port in the rear of the carb. I just ran my Pcv valve to a port right under the carb in the manifold. When I get around to grabbing the power brakes off the parts Jeep I just plan to " T " off of it.

 

[dalefan88]

what venturi size is your carb? Mine is a 1.14". Most people recomend 47 jets for the 1.08" on a AMC 258 i6 / 4.2l , but i haven't run across any recomendations for the 1.14". The differnce in cfms between the two isn't much. The 1.08 is 287 cfm's and the 1.14 is 300 cfm's so the jets should be just slightly bigger on a 1.14.

From what i've read, my 1.14 was supposed to originally come with size 50 jets but it has size 48 now, and they look like they've been in there a long time. The previous owner, petescj said it ran rich on his CJ8 , so just to be safe, i ordered a set of 47 jets. Who knows, after i rebuild it, replace the power valve with the correct one for my engine's vaccum, and take care of all the little leaks that i've read about, it might run just fine with the 48's. The great thing about these carbs is that you can swap jets easily by just removing the four air horn screws and removing it while it's still all hooked up on to the engine. I plan to have my buddy at the exhaust shop weld a bung into the pipe so i can temporarily install an o2 sensor and use the wide ban on it to set the mixture exactly where i want it.

1.08 i read between 46-48 is good.

 

[Rescue Diver]

I decided to postpone the actual head swap until next weekend. It took a lot longer to do a lot of the staging work than expected. Here's what I got done this weekend. I installed the new jets in the carb and finished assembling it. I stripped and cleaned the intake manifold. I filled the extra water holes in the 4.0 head using biodegradable packing peanuts and JB Weld. I made a throttle cable bracket for the MC2100. And last but not least, since the round cup washers will no longer do the job since I'm using mismatched year's parts, I bench fit it all together and made some steel hold downs that will allow the 80's intake manifold to work with a 95 head and exhaust manifold.

 

[Petescj]

That looks good!!!