calling all 2.8 to 4.0 swappers

those of you who have done the swap, from an 86 2.8 v6 to a 4.0 straight 6, how much time was involved in it?

we're putting a 4.0 into beaterjeeps 86 2.8 auto. it's from a 1990 xj that I have. we're doing engine, tranny, wiring, accessories, cooling swap. also some interior swap but no biggy there.

i know what's involved in it...just kinda want your ETA on how long it took.

few factors that will play into it for me;

engine will already be resealed and painted.

tranny will be resealed/cleaned

accessories will be cleaned

the 5 or 6 wires needing splicing aren't a big deal

i have both driveshafts already

his truck will be torn down to basics (just dash) inside waaay before the swap. so, it's gonna be a gut and drop deal.

also, did the 4.0 motor mount plates bolt right into the 86 engine bay? i don't care about the fabled firewall change...i will make that work. I also have the new radiator supports ready to go so it will be a matter of chop and drop for that. also a new hood is ready for the truck too.

I knew a guy in NAXJA who did a 2.5L to 4.0L conversion, including all the wiring, in a 72-hour marathon. That was working by himself, for 72 hours straight.

I would figure if you haven't done one before you should plan on about twice that number of hours, and preferably not straight through.

I knew a guy in NAXJA who did a 2.5L to 4.0L conversion, including all the wiring, in a 72-hour marathon. That was working by himself, for 72 hours straight.

 

I would figure if you haven't done one before you should plan on about twice that number of hours, and preferably not straight through.

:P

we have about 3 people and I've torn apart all of these engine combinations before. it's just a matter of dropping it.

good to know it can be done in that time frame. I'm sure we'll get it done somewhere around that time frame.

4 people helping... ;)

I knew a guy in NAXJA who did a 2.5L to 4.0L conversion, including all the wiring, in a 72-hour marathon. That was working by himself, for 72 hours straight.

 

I would figure if you haven't done one before you should plan on about twice that number of hours, and preferably not straight through.

personally 72 hours sounds about twice as long as it would take... I would think i could do a full swap if the 4.0 was out of the other car in under 24 hours including wiring. and 24 hours sounds like a long time even. can pull everything in the 2.5 in 4 hours i bet. 72 hours just sounds like a real long time..

yeah. 4 people now :D

correy you in? tim?

we can make this a wrench-a-thon. donations accepted for the Beaterjeep Foundation :D

are there any indications that you guys noticed while doing the swap to know if that 86 had the firewall interchange for the 4.0L? the best way of telling, has been destroyed basically, the sticker on the door. if so, there's a auto 4.0L mj sitting at a gas station here it's not a 4x4 though (it's been there for awhile), the guys also uses the station for a car lot. if i can find out if the firewall in my 86 was one of the ones that had been changed, i will go talk to the guy and see what he wants for it, and do a 4.0L swap myself.

we haven't done the swap yet. not for another 3 months or so

anyways, people don't understand.

if the firewall is even slightly different, a BFH will fix the issue quick fast and in a hurry.

haha i understand that, and i have BFH, but if i don't have to use it then all the better. people have said mid 86 they interchanged the firewall to fit the 4.0L, i just want to know how i can find out, without ripping out the motor and given it a try then.

I got the engine out of the manch (2.8) right now and could take some measurments of the motor mounts and what not if that would help?

it might. if you want to take some measurements, i would like to know what they are. for some reason the engine bay of an 86 that had a 2.5 that i looked at awhile back looked smaller than the one i have, even the front end looked shorter.

I did the 2.8 to 4.0 conversion in my 86.

It took me a while (really can't give you a time amount though). But I did a ton of things while I was doing the swap, and only worked at nights here and there, so it took much longer than a straight up swap.

Here's my thread. Not alot of tech info, but pictures and stuff.

http://www.comancheclub.com/forums/view ... highlight=

Matt

Yeah I'll definitly come out to help if I can.

if the firewall is even slightly different, a BFH will fix the issue quick fast and in a hurry.

Swing away if need be. :D

Pulled the 2.8 january 8th last year, and was back on the road with the 4.0 last saturday.... Looks like i have the slow-wrenching record around here :oops:

3 people with more-than-average jeep knowledge and proper tools should be able to do this in 48 hours if they plan everything right.

And yes, the motor mount plates bolt right into the 86 engine bay.

maybe we can set the world record for a motor swap... :brows:

personally 72 hours sounds about twice as long as it would take... I would think i could do a full swap if the 4.0 was out of the other car in under 24 hours including wiring. and 24 hours sounds like a long time even. can pull everything in the 2.5 in 4 hours i bet. 72 hours just sounds like a real long time..

His donor vehicle was an XJ. He found that the XJ chassis harness didn't mate up with the MJ chassis harness and he had to make a number of custom connections, as well as trace some circuits.

Sounds like you have most everything planned out... one other thing you might want to check is the tranny crossmember. I did a 2.5 to 4.0 swap into my Comanche and the crossmember mount location on the unibody was different, not a biggie to fab up the mount to fit, but it was unexpected when I first crawled under there to bolt it up.

And yea, a BFH will take care of the firewall. If you compare a '86 firewall with a '87 or newer you will notice they added an larger indentation to clear the valve cover. Do yourself a favor and give it a few whacks before you try to drop the engine in, you should only need to make clearance for the valve cover.

Sounds like you have most everything planned out... one other thing you might want to check is the tranny crossmember. I did a 2.5 to 4.0 swap into my Comanche and the crossmember mount location on the unibody was different, not a biggie to fab up the mount to fit, but it was unexpected when I first crawled under there to bolt it up.

 

And yea, a BFH will take care of the firewall. If you compare a '86 firewall with a '87 or newer you will notice they added an larger indentation to clear the valve cover. Do yourself a favor and give it a few whacks before you try to drop the engine in, you should only need to make clearance for the valve cover.

thanks man. that's exactly what I needed to know.

the crossmember mounts already has holes drilled for it on a 2.8 I believe, just needs threaded