Engine swap in 1989 YJ

[suthrn98]

My jeep slung a rod. I am trying to find a replacement 4.2 with little luck. What kind of options do I have with least amount of downtime? I have found numerous 4.0s but I know they are all EFI, and mine is Carbed.

What would be involved with putting in a 4.0? Could I use the head and CARB setup off my 4.2 on the 4.0? I am new to this world and would love to get the least expensive and easiest way to get the jeep back on the road.

 

[jps4jeep]

get a 4.0 with as much of the computer and wiring as possible, it is worth the trouble to upgrade.

 

[Bounty__Hunter]

Since you can find a 4.0L easily enough, it would be a great time to build a 4.7L stroker motor using the 4.0L block and 4.2L crank.

 

[60biscayne]

We put a 2004 Wrangler 4.0 in our 1989 Wrangler. We also changed over from a standard shift 5 speed to the '04's automatic trans & transfer case.
There's quite a bit to it to make it happen - not rocket science but quite a few things to address. I don't think that you can just swing the 4.2 head & carb set-up over onto the 4.0 - someone else will have to advise you on that point BUT why wouls you want to keep that junk carb? Before I put in our 4.0 I had gone the route of putting a Holley 2 bbl on the 4.2 etc. but it still sucked!
1) I bought a 20 gallon fuel tank out of a 1995 Wrangler & replaced the tank in the '89 because you need a fuel pump in the tank to supply enough pressure to the fuel rail. In addition our 2004 fuel rail wanted a lot more pressure which the '95 pump could not provide so I had to get a fuel rail & injectors from like a '95 Cherokee 4.0 in a boneyard which worked out fine.
2) You have to install the computer & associated wiring from the 4.0 donor vehicle or one of the same type. This part of the swap is critical & you need somebody that understands the new type systems unlike an old shade tree hot rod mechanic like me - In my case Thank God for my buddy Mike Brennan!

*Also verify that you can hook up your flywheel, clutch & trans set-up or what do you have to do to make it function with the 4.0 We swapped the standard for the '04's auto etc..........
Bottomline: It's worth it!

 

[suthrn98]

ok, I'm back to looking for a 4.2 I don't have the time to do any swaps. I need to get it running in like a day or twos amount of time.