btm24

So its come time to where I need a new 4.0. Mine is knocking and miss firing (no thanks to the water that may or may not be inside :shake: )

So I need some options. I can go with a full rebuild but im not sure what all is good or not good with this motor. If I chose this way, what rebuild kits are best to use? This is a great time to upgrade should I think about having my crank shaft balanced and any after market parts added like lifters? Any and all info and what to get, and where to get it would be great!

I can put in a junk yard Renix 4.0 but that would be a 50/50 shot if its gonna last more then a year. Do you think this would be worth it?

Could go with a HO swap but dont know what all is needed in this kinda swap, any and all info on this would be great. And would this kind of swap be worth it?

Or I can go with a reman 4.0, If I do this what company should I get one though?

Thanks again for any and all info ya'll give!

Brandon

Slick761

I would go junkyard. These motors have a pretty stout bottom end and a valve job can go a long way. As far as going the h.o. route its more trouble then its worth. Imo the renix system is much more mod friendly anyways. I made my own adjustable map sensor and with that and an adjustable fuel pressure regulator you have full control of the fuel. The throttle body is a bottle neck so look up 99+ intake manifold on renix or something to.that effect. Someone.recently posted it I think it will give you some good info. Rebuilding is certainly a good way to go on yours or a donor of you have the know how but like I said the bottom end is strong. If you have oil pressure then a valve job will usually go a long way. If your going to do engine work a mild port and polish would be required imo. Check out standardabrasives web site for step by step instructions. Also cam lifters and springs would be high on my list while your at it. All depends on your budget. Hope that helps a little.

Slick761

BTW what kinda knock? Like rod knock? I would investigate further into your engine before getting into another one. You may be able to get away with bolts and bearings on the bottom end...... If your compression is good

btm24

Like a rod knock. This is the 2nd time I've done this twice now and before this time I was burning oil and what not so I'm sure now it's gonna need a complete rebuild if I don't swap it out...

Brandon

Slick761

Man I would really just swap it. Out here I can get a whole engine at pick n pull on half price days for like180 buck and if it doesn't work they'll give you another. You can get pretty good at swapping lol.

Slick761

And the thread I was telling you about is actually renix/h.o. hybrid with 99+ intake.... its in the tech write ups. If you're interested in making the h.o. thing work with your renix check out that thread. It will give you the info.you need.

Gee oh Dee

Link to thread?

Renix operating system, HO head and exhaust manifold, 99+ intake would be a slick setup...then poke and stroke?

Moved to chat, btw...

Beans

https://www.cherokeeforum.com/f51/re...ts-easy-47578/

Gee oh Dee

Ok, I have seen that one. I thought you were talking about putting a HO head on a Renix block for some reason. My bad.

Slick761

Pretty sure you can put h.o. head on renix.

Gee oh Dee

You can. But its not a direct unbolt swap and rebolt if Im not mistaken. There is a 'trick' to it.

Slick761

Yes and I can't remember what it is... think they did it on speed vision. Project cheap jeep.

Gee oh Dee

Its on here somehwere, I just don't have time to dig right now.