will a 94 xj engine fit in a 98 xj?

[jeepfreak1020]

I threw a rod on my 98 sport about 3 weeks ago and have been looking for a doner. I found a 94 with roughly 104k on it. Can I use it in my 98? Ive done alot of searching but cant really find exactly what im looking for. What will I have to swap between the 2, to make it work on my 98? Do I need to use the wiring harness or anything, i dont really understand why I would if Im going to use most of my 98 stuff. Tell me what I need to swap and what will work to just let me drop it into my 98. Thanks

 

[muduck18]

They are different heads.

but they should work. just have ever so slightly less power than your '98.

You will need to change all the brackets and accessories from your '98 to the 94 engine because the pulleys and belt tension-er are in different places, and IMHO the 98 has a better setup so I would encourage you to use that instead of the 94.

I think you will need to switch the distributor and coil too because of the OBD difference, but that's stuff you will need to get in and figure out. they are the same 'basic' block but some of the little things hanging off are different.
The intake (more specifically the throttle body and vacuum line ports) will be different too so swap the one from the '98.

other than that stuff I can't think of anything that would be a deal breaker.

 

[Frank Z]

Same as the last time you asked.

Swap all accessories and sensors from our current motor to the replacement motor.

It's a basic long block swap.

 

[ROBZ95Xj]

They are different heads.

but they should work. just have ever so slightly less power than your '98.

You will need to change all the brackets and accessories from your '98 to the 94 engine because the pulleys and belt tension-er are in different places, and IMHO the 98 has a better setup so I would encourage you to use that instead of the 94.

I think you will need to switch the distributor and coil too because of the OBD difference, but that's stuff you will need to get in and figure out. they are the same 'basic' block but some of the little things hanging off are different.
The intake (more specifically the throttle body and vacuum line ports) will be different too so swap the one from the '98.

other than that stuff I can't think of anything that would be a deal breaker.

There the same heads, get your info right. To the op your just gonna have to swap sensoers, distributor and coil. Its also a good time to get a new water pump and t stat, also the flex plate or flywheel are the same so you don't have to change them

 

[muduck18]

There the same heads, get your info right. To the op your just gonna have to swap sensoers, distributor and coil. Its also a good time to get a new water pump and t stat, also the flex plate or flywheel are the same so you don't have to change them

There seems to be some dispute between when they actually switched from the 7120 head, to the 0630 head and then to the 0331 head..

I'll give you my experience.

I have removed an 7120 head from a 1994, and there is one currently installed (and as far as I can tell factory installed) into my dad's 1995 xj.
This puts the 7120 casting running ON HO motors from ~91 to ~95.

The multiple 1996's that i've owned have all had 0630 heads on them,
Also My 1998 had a 0630 head on it.
and my current 1999 also has a 0630 head on it.


based on my research the 1996 model hear recieved a 5hp bump in power according to MFGR claims in the owners manual (again compared from my dad's 1995 and my 1996)

this being my experience I will stand by my information in that it will have slightly less power and a different head casting.

 

[muduck18]

http://www.jeepstrokers.com/forum/viewtopic.php?f=34&t=241

http://www.enginebuildermag.com/Art...again_the_facts_about_40l_cylinder_heads.aspx

 

[xpedition xj-eh!]

I just swapped a 93 into a 99 this summer ( my 99 is pre distributor-less ignition like your 98 ).

You probably have a 7120 head on the 94 and an 0630 on the 98 which means you just need to block off the extra coolant temp sensor hole that is not needed in your 98. It's pretty simple to spot where the sensor hole is located when you can compare the heads side-by-side. In my case, my 93 engine still had the temp sensor threaded into the head so I just left it in there to block it off (unplugged of course).

I just swapped over everything that can unbolt from the 99 long-block onto the 93 long-block. Manifolds, accessory brackets, distributor and dizzy, plugs, wires etc etc etc. Upon close inspection, my 99 had slightly different engine mount brackets than the 93, so again, swap over everything that unbolts from the head/engine and bring it over to the replacement head/engine. There is nothing to consider regarding electronics (OBD-I to OBD-II etc) because you will be retaining as much as you can from the 98. This is a purely mechanical swap.

My 93 donor engine came from an auto-trans XJ. My 99 recipient XJ has a manual-trans. When the donor and recipient do not have the same tranny, then you need to get a new pilot bearing to match the recipient transmission. No biggie, you should probably get a new pilot bearing while you're in there anyway. Just buy a pilot bearing that was made for your 98. I didn't have the proper tool to pull the old pilot bearing, so I just used an old trick to get it out.. which is to pack the air-pocket behind the pilot bearing with grease and then find a rod that is the same diameter as the inside of the pilot bearing. Put the rod in the pilot bearing and whack the end of it with a hammer such that the grease pushes the pilot bearing out from behind.

My swap turned out perfectly and has been running well for months. I had never pulled an engine before this and I easily got it done during a long-weekend. I haven't noticed any difference in power. In my case, I do notice the 93 engine is slightly harsher/coarser and I think that's because the older (pre 96) engines didn't have the main crank girdle that was added to "eliminate noise, harshness, and vibration". If you drop the oil pan on both engines, you can swap the girdle from the 98 to the 94 engine so long as you also swap crank bolts as well (they are longer). As an FYI (not pertinent to the swap), the older engines (pre 96) having steel pistons whereas the 98 would have alloy pistons (might be why the newer engines peak torque is at 2k rpm vs 3k rpm for the older engines).

My 93 engine to 99 XJ swap was not that hard and there was very little to consider. Get new engine mounts while yer at it.

I'll try to attach some pics (not mine)...

girdle that you can swap from your 98 to the 94 (optional):

temp sensor that you no longer need:

pilot bearing (shown with flywheel on):

 

[gajeepguy]

Not to thread jack, but can the girdle be fitted to the renix 4.0s?

 

[xpedition xj-eh!]

Not to thread jack, but can the girdle be fitted to the renix 4.0s?

I don't have a definitive answer for that..

But I should add that you may also need to swap the oil pan if you swap the girdle (due to clearance issues). I forgot to mention that in my post because I was swapping the 99 pan onto the 93 engine anyway. Sorry I can't be more precise on that.

 

[cruiser54]

Not to thread jack, but can the girdle be fitted to the renix 4.0s?

I believe so, but you would need the main bearing cap bolts/studs from the later motor.

 

[gajeepguy]

Thank you very interested in this mod

 

[cruiser54]

Thank you very interested in this mod

Me, too. For my stroker. But then you have to shim the girdle away from the crank with washers and I think it would somewhat defeat the purpose.

 

[jeepfreak1020]

I just swapped a 93 into a 99 this summer ( my 99 is pre distributor-less ignition like your 98 ).

You probably have a 7120 head on the 94 and an 0630 on the 98 which means you just need to block off the extra coolant temp sensor hole that is not needed in your 98. It's pretty simple to spot where the sensor hole is located when you can compare the heads side-by-side. In my case, my 93 engine still had the temp sensor threaded into the head so I just left it in there to block it off (unplugged of course).

I just swapped over everything that can unbolt from the 99 long-block onto the 93 long-block. Manifolds, accessory brackets, distributor and dizzy, plugs, wires etc etc etc. Upon close inspection, my 99 had slightly different engine mount brackets than the 93, so again, swap over everything that unbolts from the head/engine and bring it over to the replacement head/engine. There is nothing to consider regarding electronics (OBD-I to OBD-II etc) because you will be retaining as much as you can from the 98. This is a purely mechanical swap.

My 93 donor engine came from an auto-trans XJ. My 99 recipient XJ has a manual-trans. When the donor and recipient do not have the same tranny, then you need to get a new pilot bearing to match the recipient transmission. No biggie, you should probably get a new pilot bearing while you're in there anyway. Just buy a pilot bearing that was made for your 98. I didn't have the proper tool to pull the old pilot bearing, so I just used an old trick to get it out.. which is to pack the air-pocket behind the pilot bearing with grease and then find a rod that is the same diameter as the inside of the pilot bearing. Put the rod in the pilot bearing and whack the end of it with a hammer such that the grease pushes the pilot bearing out from behind.

My swap turned out perfectly and has been running well for months. I had never pulled an engine before this and I easily got it done during a long-weekend. I haven't noticed any difference in power. In my case, I do notice the 93 engine is slightly harsher/coarser and I think that's because the older (pre 96) engines didn't have the main crank girdle that was added to "eliminate noise, harshness, and vibration". If you drop the oil pan on both engines, you can swap the girdle from the 98 to the 94 engine so long as you also swap crank bolts as well (they are longer). As an FYI (not pertinent to the swap), the older engines (pre 96) having steel pistons whereas the 98 would have alloy pistons (might be why the newer engines peak torque is at 2k rpm vs 3k rpm for the older engines).

My 93 engine to 99 XJ swap was not that hard and there was very little to consider. Get new engine mounts while yer at it.

I'll try to attach some pics (not mine)...

girdle that you can swap from your 98 to the 94 (optional):

temp sensor that you no longer need:

pilot bearing (shown with flywheel on):

That was the exact info I was looking for!!!! Thank you very much! If I have any questions ill PM you man! Thanks.