compatibility between a 84 2.5 and 86 2.5

[mdwatson]

Hello I'm new to the forums. I have a 86 Mj with a 2.5 that needs a possible new engine. I was wondering if the intake and exhaust and everything else from my 86 will bolt up to a 84 2.5?

[Pete M]

low compression? rod knock?

 

 

and welcome! :waving:

[mdwatson]

I think rod knock. Motor sounds good until about a couple miles down the road then it starts knocking. It has 248,000 miles on it.

[Pete M]

might just need new bearings. :dunno:

 

I've read that any 2.5L AMC lower block from 84-04 (or whenever they switched to the 2.4) can be swapped in with minimal effort. :thumbsup:

[Eagle]

The '84 and '86 engines are basically the same. But the '84 was carbureted and the '86 was throttle body injected. What I don't know is if the intake and exhaust port heights and shapes changed when the went to injection. It's worth a look. The worst case would be using the head off the other engine.