4 Cylinder Engines in CJ7

I was wondering how good the 4 cylinder engines are in these jeeps. Is it a good option for medium-core 4-wheeling on the cheap? I know the I6's are great (I used to have a Cherokee), but will the I4 be a good compromise with gas prices the way they are? Also how about the longevity factor. How many miles can one expect to get out of this engine?

Thanks in Advance John

Reply to
John Norman
Loading thread data ...

The 4 cyl and 6 cyl are both extremely durable engines. Both will run to

150k miles and up as l> I was wondering how good the 4 cylinder engines are in these jeeps. Is
Reply to
RoyJ

Reply to
L.W.(Bill) Hughes III

Afaik, the four cylinder is a GM offering, with the same bell housing pattern as a small block Chevy or the 4.3 liter V6. The 5.7 liter fuel injected small block is an ever better compromise. ;^)

The I4 isn't so great for highway use, just because of the horrible aerodynamics that you can't get away from with a vehicle shaped like a shoebox, but off road you may have some advantage, and the axle ratio should be the sensible 4.11 that they mated with four cylinder engines.

Longevity will depend on what the engine has been through in the past, and what you do once you get it. A compression test would be a good idea.

Earle

Reply to
Earle Horton

Still a "Real Jeep" though...

Reply to
Matt Macchiarolo

I don't think so, as I recall that engine is basically the 4.0 with two cylinders missing.

Jeff DeWitt

Earle Hort> Afaik, the four cylinder is a GM offering, with the same bell housing

Reply to
Jeffrey DeWitt

Umm, they didn't make the 4.0 when the CJ's were around. The 6 is a 4.2 from that era.

The later CJ 4 banger is a GM product.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Reply to
Mike Romain

Maybe I'm misremembering but I seem to recall they needed a new 4cyl engine and took the old six, removed two cylinders and redesigned the head for better flow. The then took the "new" 4cyl engine and added two cylinders to make the 4.0. For what it's worth both engines use the same replacement pistons.

(Autozone says a Badger P830-20 for a .020 oversize piston for either engine).

Jeff DeWitt

Mike Roma> Umm, they didn't make the 4.0 when the CJ's were around. The 6 is a 4.2

Reply to
Jeffrey DeWitt

Reply to
L.W.(Bill) Hughes III

formatting link

Reply to
Jeffrey DeWitt

The Cherokee got these engines first, then the Wranglers got them. Afaik, none of them made it into CJs. I have the 4 cylinder engine in my Wrangler, and no speeding tickets so far. ;^)

Earle

Reply to
Earle Horton

Reply to
L.W.(Bill) Hughes III

Highway speed limitation is all about the CJs stability, or lack thereof. The four-banger will get you up to freeway speed just as well as the V6. The

4 is also highly reliable and very field serviceable and off-road is one of the best. V6 only has an advantage if towing imo. But anyway, the CJs were the best Jeeps ever made and either one is great.

Michael

Reply to
Mike Stevens

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.