4 cylinder cjs

[craveman85]

Any of you guys have any pictures of your 4 cylinders you'd like to share? As much as I want more power I'm keeping the iron duke in my 81 CJ8 rebuild and would like to see some others enjoying their 4 bangers.

 

[Torxhead]

This guy here made quite a few improvements to a 4 cyl. YJ years ago, hope it can help:
Popular Modifications
I really like to see the simplicity of a four banger under the hood of a CJ.

 

[daddyusmaximus]

My first CJ, a '69, had the 4 banger. I like having more power, and I love the sound of a V-8, but that little Jeep went everywhere I pointed it.

 

[Belizean]

I have the AMC 4 banger in mine since new with 235K miles and still working great. Best things I ever did was the Webber carburetor at 90K and the MSD at about 210K and wish I had done that far sooner. I'm working on a AMC 258 i6 / 4.2l rebuild and hoping to do EFI with that. Sorry no posted pictures haven't figured that one out yet. Scrambler forum works good at that. Only time I really need the 6 cyl would be a little bigger tires and going down the interstate

 

[craveman85]

Here's mine when I got it. I keep changing my mind about what I wanted to do with it. I keep wanting to make it all original. Not a prefect restore but close. Had the GM 151 /SR4 . It needed a repaint and some kids destroyed the motor. I just bought a rebuilt short block with a3 year warranty shipped for under 500$ nobody really wants them anymore. I have a Weber carb upgrade, a hedman long tube header, and a comp cam complete kit for it. I'm buying a rebuilt head off eBay for a newer s10. I'll have better flow and a small bump in compression. Currently looking into better manifolds than oem. Might even make something myself. I don't need the radical 4 barrel race intakes.

 

[Belizean]

Nice looking!

 

[craveman85]

Hoping to go from 80hp to 100 hopefully

 

[Belizean]

I really don't know what the horsepower on mine was, but I just looked up the AMC 150 and it said 105 hp. I don't think I have lost much power over these years. I know the Webber ad at the time said up to 20 percent more power and I think I got that. Original carb was terrible I that much for sure.

 

[craveman85]

I think my 100hp goal is a little conservative. I'll probably be closer to 120 but I'm not setting myself up for disappointment.

 

[Torxhead]

I see you do list 3:73s on your CJ, and think that is a little tall for a four banger. I do believe the later CJs with that engine came with a 4:11 ratio. That does put the freeway rpms on the high side though. My point is that changing the gear ratio will give your CJ a little boost on the low end. Along with keeping the overall weight down where you can like don't put a set of 35" tires on it.

 

[craveman85]

I'll probably keep 373 unless I do swap the Transmission for a 5 speed. For the cost it's not worth it to change to 410s as I'll see mostly street usage. Off road I can use low range. I'll be using 30x 9.5 for now. If I go 5 speed it will probably be 4.56 and 31 or 32.

 

[Hedgehog]

Using 30" tires should be great for your 4 cylinder engine. I ran 31's with mine with no problems and that was with 2.72 gearing. 3.73's should make for very decent off road power.

 

[craveman85]

I don't know how anyone could buy a vehicle with less than 3.54 unless they never test drove it. Or it had 25" tires.

 

[Lumpy Grits]

I don't know how anyone could buy a vehicle with less than 3.54 unless they never test drove it. Or it had 25" tires.

People bought'em, because we had no choice in some states. My only choice was 2:73 or 3:31 w/6cyl engine.
LG

 

[Hedgehog]

I bought my first CJ5 from a friend. It being a 1980 model, it had 31x10.5's General Grabber tires, SR4 Transmission , 2.72 gears, Dana 300 Transfer Case and a GM 151 4 cylinder Iron Duke engine. We hunted a lot in that CJ, it was great fun. I guess I was to ignorant to know it was one of the worst combinations jeep ever produced. That CJ served us well. He sold it to me and I enjoyed it for several years until the engine and the SR4 got tired. They were replaced with a Buick 331 V6 and Ford T-18 . That jeep was GREAT, even with 2.72 gears. .... I was just to ignorant to know how bad it was. My first child required the CJ to be replaced by a Trooper II. I still miss that jeep. Keep the tires a reasonable size and even 2.72 gears aren't all that bad.