4cyl swap to Inline 6

[a1awind]

So in that case...is it more or less the same amount of work to swap in a H.O?

[Lewt2007]

 

The ax-4 (4-speed) or ax-5 (5-speed) that is behind your 2.5 isn't even close to being beefy enough to last behind a 4.0L, and the bellhousing pattern doesn't match up to the 4.0L either. If you swap in a 4.0L, you'll have to modify your firewall and the front radiator area of your jeep because it is an '86. The dimensions of an ax-15 are different. It is usually all bolt-in for most Cherokees, but yours might not be because it is an '86 and they didn't have the 4.0L until '87 IIRC. One popular swap is to put in a 3.4, which will mount up to your ax-5. A better option, unless you have a lot of money into the BODY of your XJ, is to simply buy one with a 4.0L/AX-15, then swap everything you want from your cherokee onto the 4.0L one and sell your current one.

You are correct as the 4.0L will not fit into an '86 MJ. They redesigned the whole engine compartment in '87 to fit the longer 4.0L in there. I've seen GM 3.4L and 3.8L engines swapped in place of the 2.8L but haven't seen too many 4cyl's upgraded. There was an AX-5 behind the 2.8L in mine but that was only cranking out a whole whopping 140hp.

 

I chose to swap in a Chevy 350 instead of fighting with the 4.0L (was looking at putting more power in there so was either going to be a 5.7L V8 or 4.7L stroker). Novak makes adapters to put an AX-15 behind the engine and they make motor mounts to fit, but the motor mounts will have to be slightly modified to fit the '86.

 

I'm not sure exactly what you're planning on doing with this Jeep but you will need an AX-15 5sp manual trans if you intend on going with anything larger than the V6.

my body was a 86 2.5 and i put the 4.0 out of a 90 in it without modding the firewall the difference is in the core support area not the firewall 

[mvusse]

Early 86 does have a different firewall, and it needs a little massaging with a sledge hammer to clear a 4.0. Later in 86 they started using the 87 firewall which was designed to fit a 4.0.

 

Sounds like your 86 is one of the later ones.

[Jeepjeff859]

I'm doing this same swap right now using a engine from a 1994 grand Cherokee and parts from a 1993 Cherokee will the motors mounts still bolt up?