smithj

Ok so i have 96 4.0l that i want to stick where a 2000 4.0l was. Im used to gm v style engines where everything is usually the same. What will i have to do as far as plumbing differences and ignition setups hopefully i get some guru advice.

JPXJMOAB

I know '00 used cool packs .. You're gonna have a fun swap with this one.

extrashaky

The coil rail should be no big deal. That should be just a matter of making brackets to hold it on the older head.

Is the 2000 a CA emissions vehicle with the two precats and four O2 sensors? If so, you'll have a challenge with the exhaust, since you can't use the stock '00 manifold with the earlier head, and you can't use the earlier manifold with the twin precats, and the computer needs accurate readings from the O2 sensors to set the mixture.

smithj

Yea the 2000 has coil packs the 96 has distributor setup. I would like to keep as much of the 96 stuff as possible. The exhaust setup would not bolt on the block though?

smithj

I guess really what id like to know is it worth it or should i just part it all out

JPXJMOAB

definitely worth it if the Jeep is worth it IYO

smithj

The exhaust actually has what I'm assuming is holes for o2 sensors however they are filled in with a bolt (double manifold setup)

extrashaky

The exhaust ports on the 2000's 0331 head are different from the ports on the 1996's 0630 head, so the 2000's exhaust manifold will not match up to the 0630 head. It will physically bolt on, but the exhaust ports don't match. You would have to use the exhaust manifold and down pipe from the 1996.

Where you run into a problem is that there were two versions of the 2000 exhaust. The CA emissions version had four O2 sensors and two extra catalytic converters. It looks like this:



The EPA emissions version does NOT have those two big bulges for the catalytic converters. The holes in the manifold for the upstream O2 sensors will be capped, and you'll just have a twin down-pipe. You also only have two O2 sensors, one down under the firewall and one at the rear of the vehicle behind the main catalytic converter. The down pipe looks like this:


Yay! No cats!

If you have the EPA version (which it sounds like you may), you will need to use the exhaust manifold AND down pipe from the 1996, along with as much of the '96's exhaust as you'll need to make it all fit. I don't know if they moved anything in that area for the 2000 that might be in the way of the '96 exhaust, so you'll have to be ready to make adjustments for fitment issues. One big problem you may encounter is that the 2000 has a low-pinion front axle, so the front drive shaft is in a slightly different location from the '96 and may interfere.

If you have the CA version with the extra cats and O2 sensors, you have a bigger problem because the computer needs the data from those sensors unless you swap the computer from the '96 as well. However, it's also against board rules to discuss removing catalytic converters from the vehicles, so the amount of help you can get here with that would be extremely limited.

The swap can definitely be done. A number of people with the 2000 EPA emissions trucks have swapped their cracked 0331 heads for the 0630 head from an earlier year and made the exhaust adjustment.

One suggestion: If you have the EPA twin down pipe (without cats) and it's not rusted through, don't throw it away! Those things are difficult to find, and the only aftermarket replacement is crush-bent and doesn't flow as well. If you put it up for sale on the board, someone will ****** it up.

Personally, I'd do the swap and figure out how to make it work.

smithj

Thanks extrashaky I guess now the big question is spark does the wiring match up if I take out the coil pack and plug into the distributor setup also swapping computers or am I'm thinking that's to easy lol

extrashaky

I think in the past people have kept the later model computer and just kept the waste spark system that uses the coil rail. It's actually a better, hotter ignition system than the stock distributor system from earlier models. The distributor has to come out and be replaced with the camshaft position sensor from the 2000 that tells the computer when to fire the coils. I recall that some people had some fitment issues with that thing in blocks that originally had distributors, so you may have to swap out a gear. I haven't done it myself, so it's a little over my head.

Personally, I like the coil rail despite its weirdness. However, if you decide you don't want to keep it, it's a relatively simple mod to get a Chrysler/Dodge six cylinder coil pack and mount it next to the coolant overflow bottle, then run plug wires from the coil pack to the plugs. That would also solve your problem of having to make brackets to support the coil rail on the 0630 head.

This is often called the "Viper" coil pack conversion, because you can use the coil pack from a Dodge Viper (it has a six cylinder pack and a separate four cylinder pack, so you just use the one for the front six). However, that same coil pack was used on Dodge trucks and a number of Dodge and Chrysler six cylinder vehicles. The pack has three coils in it just like the stock coil rail, and the computer recognizes it and plays nice with it right out of the box. You just have to mod up a way to mount it, extend the connection from the rear of the engine bay and cut some plug wires. Plus those coil packs are cheaper than the coil rails. You get no performance bump whatsoever from this mod; you only want to do this to solve the bracket problem or just get rid of the coil rail to make it easier to get to the plugs.

smithj

With the camshaft positioning sensor in I don't have to mess with timing then correct?

Fred/N0AZZ

No your going to have problems period with the wiring and the ECM unit. There are others on here that can give you all the pro's and con's of this swap, so far they haven't chimed in with the details.


All 00/01's had 4 O2 sensors and 4 cats and the coil pack get info from them via the ECM as when to fire as a lot of other info.


The other option might be to sell all you have and buy a good pre 00 a 97-99 being the best choice's JMHO.

extrashaky

Not true. Some 2000 model XJs had EPA emissions, which had only one catalytic converter and two O2 sensors in the normal locations. I know this to be true because I have one. I ordered it that way when I bought my 2000 new.

The CA emission XJs that had three cats and four O2 sensors were an option in 2000 for vehicles sold outside of California. You could buy the truck with either EPA emissions or CA emissions, your choice. In 2001 they made CA emissions standard on all XJs nationwide, so that all the 2001s had the extra cats and sensors.

OP said he had plugs in his manifolds where the extra O2 sensors would go, so it appears he also has a 2000 EPA emissions vehicle. That's good news. The 2000 ECU will not care if he's running the 0630 head, '96 manifold and single down pipe, because both the 1996 and 2000 EPA XJs have the same number of cats and O2 sensors in the same locations. The only problems he may run into using the '96 exhaust would be fitment issues.

I recall that someone who did this swap earlier ran into some issues with the camshaft sensor, but I don't remember what they were. Theoretically the sensor should tell the computer when to fire the coils, and the computer should handle the timing. You may want to ask specific questions like this on the modified tech board, where they might attract the right attention.

Be sure to take lots of pics during this process and make a thread on it for people who need to do this in the future.

smithj

Lol I'll let everyone know how it goes if I ever remove the 96 engine. The two E style bolts on the top side of the bell housing are stripped, I'm assuming someone tried this before. Any suggestions on getting these bolts out

no space to drill or cut or anything. I'd rather not remove the tranny and engine together

JPXJMOAB

Irwin tools makes a bolt extractor that will work