[yjcrawlr]

I thought I would do a build thread to make the information on the swap easily obtained. I aquired a 95 cherokee 4.0 HO with 86k from my friend Willie complete with wiring harness and ecu. The swap is happening on Saturday at the shop where Willie works at and I will take some pics and show all the new stuff. I decided to keep my 90 bellhousing and 90 AX-15 transmission so the clutch kit was for a 90 and I went with a zoom kit complete with new internal slave cylinder. While the engine was out had the head flow tested, its getting a new front and rear main with all gaskets, oil pump, water pump 95 wrangler (because cherokees have a offset fan), and timing set. A few things were missing so I had to get a throttle body(off a 94 grand cherokee) and power steering pump tensioner bracket. I will post some pics of the engine parts and swap as it goes. For now here is one last look at the old engine before it gets parted out.

[frhrwa]

so.. someone tell me the difference in a 4.0L and a 4.2L besides the .2... and what are the motors starting at 4.0 and going up to the v-8's..

[Jeebs]

Biggest thing would be that the 4.0 is FI while the 4.2 is carb. The 4.0 has more HP and torque as well.

[tygo]

looking forward to this write up, if my 4.2 dies again I'll be doing this same swap so as much detail as possible would be extremely helpful. Thanks for posting!

[yjcrawlr]

Here are todays pics, I have been working on collecting the parts and stripping my engine of is accessories to get it ready to pull on Saturday. My pilot bushing-bearing arrived from Novak today it is available from both novak and Advanced Adapters I found advanced adapters to be very knowledgable on the swap I was doing but I had allready ordered the bushing from novak. I will buy a Atlas from Advanced Adapters one of these days when my budget allows. I also picked up the water pump today because my cherokee water pump offsets the fan so I got a new one for a 95 wrangler.

Pilot bushing bearing


Engine getting stripped of OBA, accessories and exhaust


Clutch, timing set, and water pump

[yjcrawlr]

I went to my frined Willie's shop this weekend to work on the jeep and here are the pics.

Here is the new engine with the new timing chain and timing cover installed.



This is the bottom end of the engine after Willie install the new oil pump.



Spagetti wiring being removed from the engine bay.



The New harness with fuel injection!



Engine got a paint job



The engine and wiring harness pulled.



Willie installing the new clutch slave cylinder.



Here is the engine put mostly back together and ready to drop in.



The next pic you should be seeing is the new engine in the engine compartment but that didn't happen because Novak sent me the wrong pilot bearing. We jumped in the part mobile Willie's yj.


after several parts stores a pilot bearing could not be found so the swap is on hold for a few days. At this point it was time for a beer PBR was in the house.

[frhrwa]

was your original motor a 2.5L? if so, what did you do about motor mounts? are they in the same location for the 4.0L/4.2L to bolt up? The oil pump you mentioned, is that a high output unit or? and since your putting it in a wrangler also, the water pump you mentioned, offset and ?.. which do I need for my 4.0L.. any other items that I should change while the motor is on the engine stand? thanks.. wayne

[yjcrawlr]

If you read my Original post at the top of the page you would have the answers to most of your questions. I am always happy to answer peoples questions so here goes.
My engine was a 4.2, some one had swapped in a 85 4.2 into a 90 yj not a legal swap. I did not swap in a high out put unit because high output units are not the best for rock crawling. The water pump on cherokees offset the fan to one side. I want to run electric and mechanical fans so I wanted a centered fan like yj came with. A 95 yj water pump was the answer. Just buy a wrangler water pump and bolt it on your cherokee motor. 4.2 and 4.0 use the same motor mounts so no work there. I had the head gone thru and milled flat, put on a new timing set, rear main seal, head gasket, oil pump, water pump,pan gasket, valve cover gasket, clutch and clutch slave, basically I want to make my 80k mile engine as reliable as I can so I doesn't leave me stranded somewhere. I wasn't really going for performance because I am all ready gaining 50hp or so and I can up grade some things later to boost the power if I want.

[yjcrawlr]

I called Novak today and they couldn't help me, they are refunding my money on the pilot bearing they sent me. I talked to advance adapters today and they are sending me the right one. Till then the engine will be on the stand.

[giggityjeeper]

Originally Posted by Jeebs

Biggest thing would be that the 4.0 is FI while the 4.2 is carb. The 4.0 has more HP and torque as well.

alwasy thought the 4.2 was torquier.....but the 4.0 had more HP???

[yjcrawlr]

The 4.0 HO will make more torque and about 50 more HP. It will also run steeper inclines without stalling. The 4.2 makes good torque down low in the rpm's. The best of both worlds would be a stroker motor with fuel injection!

[yjcrawlr]

The new pilot bushing showed up from advance adapters and it was the correct one, so last night we finished putting the engine in.

Here is Willie right after he pulled out the clutch alignment tool.


The new 95 HO just dropped in.



Here is how it sits today, need to hook up some more wires, bolt on some accessories, and hook up the fuel lines still.

[yjcrawlr]

I got the jeep back into the garage tonight, it is supposed to snow on sunday. I lack a throttle cable, temp sending unit, exhaust down pipe and pcv valve. I am going to the junkyard in the morning and should be able to pick up these parts so I can start-er-up.

[yjcrawlr]

Here is a driver side view I forgot to post.

[frhrwa]

are you ready for a vacation in Las Vegas..? your install looks great! come on over, I need to do mine too.. ha..