Engine swap 2,8 -> ???

[Joop]

Hi everybody.

 

I have just bought my first MJ and i had it for a week now. So far it i am realy impressed by its performance :D But.... the engine looks realy bad, and doesnt run very well. I would also like som more power.. Has anyone got a tip about another engine thats fits right in?? A quick search on the net showed me a hole bunch of models, all based on the same block (94 camaro 3,4Liter, 91 izusu trooper 3,1Liter etc ....)

 

Is it worth locking for something like that or is it best just to fix up the original engine??? Has anyone out there tryed it before??

 

I want something that fits right in without a lot of cutting/welding as I understand is necesary if i put the inline 6 in my 86 model.

[JOMJ87]

I want something that fits right in without a lot of cutting/welding as I understand is necesary if i put the inline 6 in my 86 model.

 

You can get by with just a hammer from what some say and then the 4.0 will slide in. Others have done it and I am sure they will chime in and also welcome to the addiction.

 

Cole

[Oizarod115]

not sure what 3.4 liter the people around here have researched/swapped but i know the 3.4 is a prominent engine swap for the 2.8.

 

as for the inline6 the later year 86s will have the extra clearance that is needed however the early year ones will not. so check first, the i6 might slide right in for you, it might not.... it was a mid-year switch

[GirsMJ86]

the 3.4 is a good swap and i would also take the injection system from the donor car also. but my 2.8 i just bored out to a 3.2 and it worked well. might have been able to go a bit further too but idk. my 86 did great once i did that to it but the rear main didn't seal and i didn't want to mess with it. and the 4.0 might fit nice if you got lucky with a late year 86. just get a build sheet anf find out when your 86 was made.

 

Alex

[Scott86mj]

Does your firewall have the area behind the vavle cover recessed. This is my 86 that had a 2.5 The 4.0 fits just fine. Had to modify the header panel and radiator support but no big deal. If you are serious just buy a cherokee with good drivetrain and move it over.[/img][/url]

[Pete M]

The 4.0L swap requires a new trans, new driveshafts, possibly a new t-case, and definitely a complete wiring harness (including the stuff under the dash). A donor rig and factory shop manuals are highly recommended.

 

The 3.4L swap can be as simple as swapping in the new block and getting a better carb (do NOT use the crappy Jeep one again).

 

http://www.off-road.com/jeep/cherokee/x ... 4swap.html

[Car RamRod]

+1 on the 3.4 swap; I am planning to do one next summer.

[Joop]

The 4.0L swap requires a new trans, new driveshafts, possibly a new t-case, and definitely a complete wiring harness (including the stuff under the dash). A donor rig and factory shop manuals are highly recommended.

 

The 3.4L swap can be as simple as swapping in the new block and getting a better carb (do NOT use the crappy Jeep one again).

 

 

Looks like i have to go V6 hunting... I just looked under the hood and a inline6 fits but that would be the second choice if its possible to do it easyer.

 

Ps: The stock varajet II carb was replaced with a weber yesterday. I have had enough of varajets in my other cars....

[possum]

A buddy of mine has a 3.4 in his cherokee. He had the 2.8 and said it was a breeze to swap.

[GirsMJ86]

A buddy of mine has a 3.4 in his cherokee. He had the 2.8 and said it was a breeze to swap.

 

yep straight bolt in. some places online carry crate if you can't find an old jy one.

 

Alex

[hemi_comanche]

3.4l all the way. If your mildly mechanically inclined you can do the swap in pretty much a weekend. I did it in 4 days working from like 9-4 each day, with an hour lunch break.

 

The best thing to do is definitely get rid of the crap Varajet.

[beaterjeep]

Since this topic has been brought up now, what about the 4.3L? Does anyone know if that is a direct swap as well, because I know where there's an S-10 sitting with a 4.3 Vortec that runs for only $400.

[Pete M]

It is not a direct swap. The 4.3L is a 90* V-block and the 2.8L and 3.4L are 60* V-blocks. They use completely different parts and bolt-ons (trans/exhaust/mounts/etc). It has certainly been done before though and the 4.3L puts out good power. See advanceadapters.com for what you would need for a 4.3L.

[feerocknok]

I've heard the 4.3L is the SBC shortened to 6-cylinders. Any confirmations? Same trans bolt up and such?

[GirsMJ86]

oh one more thing about the 2.8 to 3.4 swap. the 2.8 is externally balanced and the 3.4 is internally balanced. so you need to take the fly wheel and have it machined down or get a new one. I'm not even sure if that is the part you need to take or get. it has been awhile since i looked into the 3.4 swap. maybe someone else can correct me on that.

 

Alex

[Eagle]

I've heard the 4.3L is the SBC shortened to 6-cylinders. Any confirmations? Same trans bolt up and such?

Correct.

 

Swapping in a 4.3L is just as much work and requires just as much fabrication and/or aftermarket adapters as a SBC V8. There's a guy near me who had one. I asked him what he thought once he'd finished and his reply was 'NEVER AGAIN!"

 

Go with the 3.4L. Just remember that the 2.8L used an externally balanced crank, meaning that the flywheel has an eccentric weight somewhere on the perimeter. The 3.4L is internally balanced, so you'll have to take your stock 2.8L flywheel or flexplate to a shop and have it neutral balanced.

[Joop]

I've heard the 4.3L is the SBC shortened to 6-cylinders. Any confirmations? Same trans bolt up and such?

 

All the same, the 4.3 is same bore & stroke as 5.7 v8 and external parts are also identical.