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4.2 to ZJ V8 swap

xjh3

NAXJA Forum User
Location
Moodus, CT
Ok, my friends and I have an '89 YJ trail beater with the carbuerated 4.2 in it. There is nothing really wrong with it, but we would like a V8. There is a pick'n'pull about an hour away with a 1993 ZJ in it with a V8 (not sure if that means it is a 5.2 or 5.9, but either way its better than what we've got now).

So, my question is:

How hard would it be to make this work? Is it plausible on a budget, or should I just leave it as one of those things that is fun to think about? In order to avoid having to buy the computer, could we some how convert it to carbueration? and would it even bolt up to the auto tranny that is in there now? What would need to happen, I would think probably some fabrication for mounts and stuff, but what else?

Sorry if this is a totally off the wall question, I am somewhat new to this stuff.

Thanks in advance
 
I know there may be more compatible engines out there, but this is the one we can get most easily and its affordable.
 
xjh3 said:

I don;t think you'll find a lot of people who have done anything with a Jeep V8 past 1986 or so. Now a Chevy 350 will get you tons of advice.

I'll say this, if you swap to any engine besides a 4.0 stroker, you can't think of it as an "engine swap" because it's not.... it's a "entire drive train and entire electrical harness swap". And it wont happen for anywhere NEAR the cost of that ZJ motor. In fact you might want to buy the whole ZJ for starters.
 
for for heaven sakes DON'T convert a fuel injected motor back to carb....

the FI would be a good upgrade for the 4.2 by itself.
 
kewlkatdady said:
for for heaven sakes DON'T convert a fuel injected motor back to carb....

the FI would be a good upgrade for the 4.2 by itself.

My friend bought a '89 YJ with a '97 4.0 HO, some moron converted it back to a carberateur, it sucks.
x2 on converting FI back to carb
So, find a G-waggy, steal the 360, do that, if you can't find any there are thousands down here, actually I know of one that might be near you

If you and your friend have the shop, time, patience, $$$, then go for it, a FI 5.2/.9 YJ would be sweet though
 
xjh3 said:
I know there may be more compatible engines out there, but this is the one we can get most easily and its affordable.

trying to plan the swap around an easy to get your hands on/affordable engine is a nightmare. You're gonna end up having to change alot more things, fabricate more stuff, buy more adapters, etc... sure a Chrysler 318's been done, but its not the easiest. In the end you'll find that the money you saved buying that 318 instead of something else will be spent, possibly two or three times, on the parts you need to make it work.

The AMC V8 would be the easiest. Next would probably be the Chevy smallblock, if only because its been done a million times.
 
PNP engine- $100

parts to make it work- $1000

The look on your neighbors face when the new owner tows the non running hulk away becuase you couldn't figure it out-

PRICELESS!

If you want to do it then get the transmission and Tcase, all wiring, computers, beer- lots and lots of beer, you're gonna need it!
 
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