Inherited CJ7

[Belizean]

I have an 84 CJ7 with the 4 cylinder with 235K miles and still running strong and good. I do know it won't last forever. So I have been reading and looking around and studied what other people have done. A lot of people have gone to V8s but I don't have the desire for or need for speed. I probably have a cheap and pretty good candidate sitting right in the driveway, my wife's 96 Cherokee with 4.0 with only 80K miles running well. For years I always thought that would be the engine I would install eventually in the 7. In the end I decided that was not the way for me. I found a 6-AMC 258 i6 / 4.2l and will rebuild and MPI. I know this will cost a lot more and probably not the smartest thing but I'm doing it my way. I probably could have spent some money on the 4.0 to get some low end torque but went a little different direction. That is what makes the Cj so great. Anybody can do what they want to make it their own style. This is just the way I decided. Do yours how you want. Good luck!

 

[Lumpy Grits]

OP-You can go with anything you like. It's your Jeep.
One issue is what's in your budget for the engine build.
Every 'horse' under the hood = $$$$$
What are your plans for this Jeep?
How much of the work will you do yourownself?
Also-Alum. heads aren't that big of a deal and have thier own issues.
LG

 

[Photonfanatic]

My hot rodding comment was a response to the idea of using a turbo charger in a gas engine which is a relatively high RPM performance enhancer. Bottom end power generally doesn't come from a turbo charger.

Yeah that was something I was going to need to do more research into. I was going to look into what most people would call a small/very small turbo. Still might not be a big help, but I heard the smaller the turbo, the less the turbo lag. So if you had very low turbo lag, maybe it could help out even on a jeep. Not sure at this point.

I really like a V6, they are shorter which can add some options. My favorite engine in a CJ was a Buick 231 V6. Those are difficult to find now and with all the great V6 options out there that is the direction I'd go. Another consideration is the great mileage the new V6's are getting these days.

So you'd be referring to something like what would have come in say a... 1991 Buick Lesabre, correct? That v6 engine. I know it had a lot of other variations and cars that it was in, but that's basically the one you're talking about, if I'm not mistaken.

But as for modern V6's, it looks like the 08 buick enclave V6 would be a very nice one to have. 275hp, 256lb ft of torque. Bump it on up to 300/300 with a few mods. They are a bit expensive though lol

What are your plans for this Jeep?
How much of the work will you do your own self?
Also-Alum. heads aren't that big of a deal and have thier own issues.

My plans are all best described as light. Light rock crawling, light mudding, light trail driving. Any more than that and stuff starts to break. Breaking stuff that I have built just sort of goes against my nature, unless it was something unavoidable, and/or was going to be replaced with something better anyway. But I think with light mudding, rock crawling, and trail riding, breaking stuff probably won't be too big of an issue. I don't currently have an offroad vehicle, so even just doing it "light" will be a lot of fun for me and the wife.

As for the work, I'll probably be doing nearly all of it myself, except for the body work. That I'll leave to a good body shop so it for sure looks great.

 

[Lumpy Grits]

Rock'n and mud'n you'll need torque to come in just off idle and gears to 'walk' the rocks.
What size tires will you be run'n?
Also-Think hard about a full locking diffs over LSD.
Did you ever get that VIN info?
LG

 

[Photonfanatic]

Sounds like I might want to say that I'd like it to have some form or fashion of road manners. I know they'll never be great, but I would like to drive it to the offroad trails/parks. And not have to tow it there. I'm really not even sure if that's applicable at this point, but I thought I'd throw it out there.


Yeah hopefully her dad will text me the vin tonight. I'll post it up as soon as I get it. As for tires, he used to run 33's. Not real sure what is best for us yet, when it comes to tires. Tons of variables lol

But back to the engine talk... I thought it would be something of a fairly easy job to pick the engine. But, that was before I learned how much CJ7 's weigh. According to google, its about 3700lbs. Give or take depending on some different things. But somewhere in that general area. Looking at it, I would have guessed much lighter than that. I would have guessed somewhere in the area of 3,000-3,200. Therefore, the engine choice would be a bit less significant, because the car or truck it came out of, would have weighed a good deal more than the jeep.

So how does all that work out, in terms of off-roading a CJ7 ? I'm just not seeing 150hp/150tq being enough. To me, it seems like you're going to be a lot better off with about double that. Hopefully you guys can fill me in on how all that translates to reality.

 

[Lumpy Grits]

Look at the Jeep database section(top of page)and see what others have done to their Jeeps. There's a bunch of good 'wrenches' on this site.
Are there any Jeep/4WD clubs near you, that you could hook up with for guidance?
The only time I wish I had a strong 8 is in the sand dunes. My son has a built, AMC 401 Interceptor in his CJ5 . That thing is a rocket-
My AMC 258 i6 / 4.2l /6cly has served me well for over 31 years and has 116K+ miles on it. I have never been inside the engine farther than to reseal the valve cover a couple of times.
Cry once-Build it 'rite' because going cheap saves you nut'n in the long run.
LG

 

[Hedgehog]

With a jeep it's all about the gearing. Especially in a 2 speed Transfer Case .

 

[Peanut Butter]

First it's a '79 CJ7 . If the Transmission is OEM, there are only a couple of choices for the Transmission and Transfer Case that you will have. If it has been modified, we will need a picture to identify. If it is an automatic, you are very Limited to your choices without replacing the entire drive line to include the rear axle. The '79 CJ7 with an automatic is the GM Turbo 400 with a QuadraTrac bolted to it for a Transfer Case . The rear axle will be an AMC20 with the center pumpkin offset to the right. Any other drive train that you swap in will most likely need a centered pumpkin rear axle. If you have a manual Transmission , the rear axle most likely will be fine to work with.

Get a positive id of what you have before you start changing everything. Also you have answered some of the questions on what you will use the Jeep for, but what size tire you think you want will also play a big factor in what you need to do to the drive train ( axles, gearing etc). Just because there were 33's on it doesn't mean it is setup to run those. Most of the other parts. like windshield, seats, etc. are an easy replace and can be done by yourself.
Metal doors around this part of the country will run you between $600 and $1000 depending on the condition. Your ideas on transmissions are great, but this is a Jeep and I would say keep it simple, but that's just me. The OEM I6 engine has a lot of torque and will power you over most anything with the right gears and Transmission . That's why I say stick to the Jeep drivetrain. It's possible to put almost anything in a Jeep to make it run, but to what end. Jeep drivetrains, worked very well for most off-road driving. My last comment would be do you want a $20000 + Jeep with all the modifications you'd like, or maybe keep it simple, and replace the needed parts and have a $10000 Jeep that works just fine and is more like what your wife remembers riding in. A lot to think about. Good luck with you build and maybe start a build thread to show the progress you are making.

 

[Photonfanatic]

Thanks for the help all. Still waiting on a text for that vin number...

They run a ranch there with 100 cows and 10 horses and a big garden, a big *** chicken coup... on and on. All I can do is wait until they decide they have time.


Something else about the engine though. I know I keep going back to that. A member somewhere else has brought to my attention, the importance of engine weight. He said a jeep needs to be light and nimble. So the weight of the engine is something of an important factor. Would you guys agree?

Thus, I should probably be looking at the 4.0L inline 6.

 

[Lumpy Grits]

AMC put V8's in them for many years.
I know a couple of folks run'n BBC(big block Chev)in theirs.
LG

 

[Hedgehog]

The CJ won't stand on it's nose if you put in a big engine. The main issue as I see it with a big engine is having enough frame to handle the power without cracking. If you want big power, I suggest adding fish plates to the frame for additional strength around the engine area.

 

[Photonfanatic]

Here is the vin:





And some more. She's a basket case but, ain't skeered.

 

[FLYNHYCJ7]

Here is the vin:





And some more. She's a basket case but, ain't skeered.

J=Jeep 9=1979 F=3 SPEED 93=CJ7 A=3,750 lbs C=258ci, 2bbl
BTW, that's gonna be a fun project

 

[Photonfanatic]

I think it will be fun. Fixing up something like that is right up my alley.

So it had a... AMC 258 i6 / 4.2l liter in it? According to google, AMC 258 i6 / 4.2l cubic inches converted to liters, is 4.22 liters.

 

[Hedgehog]

First run through of your pictures I'm thinkin' "Oh MY". Second run through, well the tires off the rims make it look worse than it really is. ..... seats are easy to find ..... second thought, is that really rust or is it paint? ..... I don't see any holes ..... where's the tail gate? ...... I'd like to see the floors. ..... Not a bad project at all.

 

[Photonfanatic]

Well I don't have any pics of the floors, but if my father inlaw is correct, they are solid and really don't need any work done to them.

As for the paint, well its hard to tell, but from what I can see it all looks to be surface rust. Which I will blast off of there. But its probably a mixture of both.

Some jerks snuck onto his property and stole the tailgate, the doors, and the hard top. He thinks it was one of his old ranch hands, since that's likely the only way anyone would even know the thing was there. That is going to set the project back by a good bit, having to pay to replace all that stuff.

But another old CJ will be saved from ruin! That's always a good thing when a classic gets saved.

 

[gr8dain]

And yes. The AMC 258 i6 / 4.2l is the AMC 258 i6 / 4.2l liter engine.

 

[Posi]

When it comes to engine weight I think of balance. An engines weighing 900lbs would certainly effect front to rear balance, especially for offroad use.

 

[Posi]

Here is the vin:





And some more. She's a basket case but, ain't skeered.

If an open Jeep sat outside in New England it would have been taken by the earth. From my neck of the woods that Jeep looks good, and plenty to work with!

 

[Posi]

The vin tags is for a 79,
I believe the body and possibly the frame is a 76-77.

For kicks, check the rear frame rails, see if their c-channel or boxed.