Will any parts from an engine in a 99+ WJ 4.0 fit on my 87 Renix

There is a 99 or newer Grand Cherokee in a local junk yard, its burnt, so all the electronics are fried, but mechanically the engine is fine, the fire barly made it into the engine compartment. I've heard stories of switching stuff like throttle bodies over from newer 4.0s into Renixs, but is the 99 too new, or will some of its parts that will give me a performance boost bolt up with or with out a bit of modification.

Grab the cylinder head and everything upwards from there. You'll have to adapt a few things to make the tbody work, but I think the fuel rail will move over from the RENIX setup.

Doing this will move you closer to HO performance from going to the improved intake port design of the HO powerplant, and I think there was another improvement for the 1999MY.

And, since most supercharging setups are designed for the HO engines, that should make supercharging and easier mod later.

How about that?

5-90

The renix fuel rail will not transfer over. I tried it, the bolts don't line up. You need an HO rail that still has a fpr on it, I don't know when they changed it but I saw a couple in the junk yard that didn't have one. Adapting the TPS works ok, but mine is constantly comeing out of adjustmant so I am working on making 65mm tb that uses RENIX sensors and bolts to the HO manifold with a 1" spacer built into the base. I would do it along with a port and polish expecially if you ever plan on stroking the engine.

Thanks for the help, I'm a bit cash strapped, so I'm not sure wether I can get the head or not. Would it be possible for me to have my Renix head ported so that it will flow almost as good as a H.O. one, or are the Renix heads just too inefficient. Also, would any on you know wether the Water pump would bolt up to my 87 head. I read that the water pump gave 2 bhp to the 4.0 because it had some new design that enabled it to turn easier.

Yes you can port the renix head to flow almost as good. Grab the intake manifold at least, you might not be able to use it with the renis head but you could sell it for more than you pay for it probably.

I would skip the 99+ heads. They have very small exhaust ports. I would keep the Renix head over it. The intake is worth a try. You can adapt the newr style TB to a Renix motor. There is a website detailing how its done.
Tom

Duh. I knew that. yeah in 99 they went to the cast exhaust manifolds and smaller exhaust ports. They also had the newer intake that is worth a try adapting, a different water pump that I have heard actually causes a loss in power, and I think it went to coil on plug ingition but that could have been the next year. I would pull the intake and TB and the fuel rail and injectors if it has a fuel presure regulator on it.

I also have a 87 cherokee wagoneer limited

i dropped a 4.6 stroker in it and i have a 58mm tb and a 1" spacer

Wanting to instal the 00 intake but clueless how to do it I have seen write ups on the 95 to 00 but since im older .....

dont want to swap out the renix system thoguht a adapter from the new intake tb to the renix would be partial solution

anyone done this or have ideas? dont want to start somthign i cant finish

The main problem is that the HO intake manifold does not line up with the ports on the RENIX head. The manifold sits about an 1/8" too high. You can grind the locating dowls off and it may work, I didn't try I just swapped an HO head on.

i tlked to mike? at accurate power about this once before he said he could grind it down and do some welding to make it line up correctly to my non ho head

why not swap to the HO head? at the time i had a 58mm renix tb and 1' spacer i dindt wnat to toss those and figure out how to upgrade to the newer FI system sensors computers etc.

maybe it I should of i dunno

often its not a matter of what would have made more sense its one of can it be done?

You could sell the bored renix and use that money for the HO intake and TB. The HO TB is 61mm and a tb spacer is snake oil. I did the swap because I was going to port and polish anyway (and I did a RENIX head too because of a junkyard mislabeling) and I was going to bore out my tb so I decided to start with something a level above what I had. I did all this in the course of a stroker build so it seemed logical to me.

Here's some info on adapting a newer TB to a Renix system.
http://www.rockmodified.com/2003/april/TB/tb_perf.htm
Since you are looking at the 99+ intake manifold, it would already be setup for a newer TB, it would just be wiring. From my understanding, the spacers help a bit on the older manifolds, but wouldn't be of any use on the newer one. With the newer TB, you could increase your TB bore to 62mm. That should help out your engine. http://www.jeep4.0performance.4mg.com/stroker.html
Check out Dinos webpage. He's swapped on a 65mm Mustang TB. I haven't looked at swapping on the 99+ manifold onto a 88 head. I am going with a 95 head and 03 block myself.
Tom

75SV1 said:

I would skip the 99+ heads. They have very small exhaust ports.
Tom

Click to expand...

Smaller does not mean the do not flow better. Is there any flow bench data that supports that the latest 4.0L exhaust ports flow worse than earlier heads. There is much more to port flow than just port size. Ford Clevland motors are a classic example. They had huge exhaust ports on the 4V heads but they flowed absolutley terrible. Plus if the intake port is crappy no exhaust port size is going to help you. I'm not saying the latest heads are better but I just wouldn't make any assumptions without some real data to back it up. After all, I don't think the factory lowered the output rating of the 4.0L when they went to cast iron exhaust manifolds.

B-loose

To my understanding the factory put on the new manifold and coil pack etc. to keep the HP up. Maybe even a cam change. The 99+ heads do have a tendency to crack. This is between the middle two exhaust ports. I will agree shape of the port does influence flow. On the Ford Cleveland heads, I understood it as the 4V flowed to much for the street. The 2V, the chamber was open style so you could only run 9:1 CR. The Aussie heads are suppose to be the best. No real experience with them though.
Tom

75SV1 said:

I will agree shape of the port does influence flow. On the Ford Cleveland heads, I understood it as the 4V flowed to much for the street. The 2V, the chamber was open style so you could only run 9:1 CR. The Aussie heads are suppose to be the best. No real experience with them though.
Tom

Click to expand...

Sort of true. The 4V head's intake port was indeed way too big for a street motor. They worked good for high RPM use but not on the street. Also, the 4V head came in an open chamber design and a closed chamber quench design. The 2V were open chambers with the exception of the Aussie head, which was a quench chambered 2V head. The Aussie heads are supposed to be best for it's combination of good street intake ports and not only the ability to make more compression but it's tolerence to higher compression without detonation because of the closed quench chamber. The 4V head still works well at high RPM but there are much better heads on the market for racing.

All that being said even the 2V heads had large intake and exhaust ports, but the 4V were mamoth on both side. And both the 2V and 4V heads had really bad exhaust flow dispite their large size. This is because of a faulty design that caused the exhaust port to flow up and then down before exiting the head. This caused horrible flow. The trick to fixing this was the cut part of the head off and install an exhaust plate with a raised port configuration.

B