4 Cylinder Engines in CJ7

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

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

Still a "Real Jeep" though...

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

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

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

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

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

Michael