CJ Engine Upgrade

4x4Wire Trail Talk Forums: Jeep, Toyota, Mitsubishi, Pajero, Isuzu, Kia, 4WD, 4x4, SUV, Off-Road and OutdoorWire Forums

Print Thread

Rate Thread

CJ Engine Upgrade #723404 05/14/06 07:51 PM

Joined: Oct 2003

Posts: 72

burtv

Getting the Wheeling Fever

I am thinking about either changing my engine or rebuilding the 256ci six cylinder (4.2L) in my CJ. Do you know of anyone changing the 4.2 head to a 4.0 HO head and adding MPI injection or is this old school? Or are most people changing out the 4.2L engine putting in a newer 4.0 OBDI or II? I like the idea of changing the head and adding MPI (might be a little more $$ but easier). Any comments on this?

78 CJ7, 83 wide track axles/Dana 30 Front W/ OX Locker, Model 20 rear w/ one piece shafts(welded tubes)/Detroit Locker, 4.10 gears. 4.5" spring lift with 3/4" shackle lift. 35x12.50 BFG MT, 4.2L, Weber Carb, K&N, T18,Scout Dana 300,Warn 9.5ti

Re: CJ Engine Upgrade [Re: burtv] #723405 05/15/06 02:33 AM

Joined: Jun 2004

Posts: 1,063

new jersey

cuervo25

Body Damage is Cool

there are tons of write ups on doing a 4.0 head to a 4.2 engine conversion.it is old school , but often you will find old school is the best school
web page
web page
web page
web page web page
Those are all the sites i have on the subject alot of the illistrations are the same but it is good.

out of all the jeeps in this town the d**n gremlin had to invade mine

I've done so much,with so little for so long i can practicly do anything with nothing

Re: CJ Engine Upgrade [Re: burtv] #723406 05/15/06 04:13 AM

Joined: Mar 2004

Posts: 2,398

Mississippi

JeePete

Body Damage is Cool

Some of the write ups recommend not using MPI and a 4.0 head on a tired engine, I swapped on a 4.0 head and kept my carb and it made a big difference, There's nothing wrong with my engine I just don't feel the expense of doing the MPI conversion is justified at this time. I'm very happy with the 4.0 head and my motorcraft 2100 carb. <img src="/forums/images/graemlins/cheers.gif" alt="" />

Freedom Off Road

Moderated by 4x4Wire

Hop To

4x4Wire Social: