several 4.0 head swap questions

[kajsdf]

i've been seeing a few 4.0 head swap kits on the 'bay lately -- anyone have any experience with these (if you can't find what i'm talking about by searching pm me for a link)?  if they are as good as they look, is the price pretty comparable to pulling one off an existing engine, cleaning/re-boring if necessary and getting all the other bits and pieces?

i am also curious what parts are necessary -- i know there are a million write-ups, but many of them are different.  i don't want any extra computer stuff if i can help it.  i know the mc21xx upgrade is necessary, and i plan to do that pretty soon anyway. 

i guess what i am trying to do is get a good idea of what exactly i need to get and how much it will cost so i can budget and plan accordingly...

thanks

[shanebo]

Tougeagle had a great write up on his conversion and he included all the prices on it. There are several plug and play kits Hesco and Mopar being 2 off the top of my head, but both are very expensive. Here is the link...check out page 5. http://forums.amceaglenest.com/index.php?topic=21335.30

[BenM]

It's my opinion that you should swap the cam - a 4.0 stock cam will do nicely on a budget. That will require new lifters too, and it's a good time to replace your timing chain since they get a little sloppy after 100,000 miles.

The only necessary parts are a couple of head bolts, possibly a sleeve set if you have the smaller bolts, the exhaust manifold, and some exhaust pipe bending to clear the front differential. Don't forget gaskets.

You need to notch the intake to fit higher and mess with some brackets, but that's just some time, not money. You're throttle assembly rides along on the intake and just needs the kickdown adjusted for the slight difference.

The only thing to beware of is the exposed casting holes that don't always seal.

It's not a direct swap, but there are no expensive parts or hidden problems.

[kajsdf]

just did the timing chain a few weeks ago, actually.

probably better to get new lifters and cam, correct?

and final question is....the jeep 4.0 liter is the same as the 4.0 offered in eagles, right?  the one listed in the engine manual supplement we have as a download on the nest?

[mudkicker715]

Eagles never had a 4.0.

Your better off getting a h.o. head and cam from a iirc a 91 to 95 jeep.

[kajsdf]

whoops, meant cherokee etc...just listed in the same engine manual.

might be a dumb question, but is there enough room to remove the cam without pulling the engine?

[mudkicker715]

Any good at cutting and welding.

[kajsdf]

nope...i guess that means i'd have to pull it...

[kajsdf]

looks like i'll be able to go pick up most if not all the parts tomorrow.  i'm having trouble locating the exhaust manifold.  will any from 87-95 work or do i need to use the renix one?

[mudkicker715]

here we go again. Haha. None work from a 4.0 are you good at cutting and welding. Sorry the 4.0 l flange needs help to fit.

I cut and welded my stroker to fit true duals. Took a few hours of trial cut weld cut weld. Blah blah. Still not happy with one side it gets knocked off from time to time.

[kajsdf]

oh, the write-ups seem to indicate the 4.0 exhaust manifold will fit but i would have to bend the exhaust piping itself to fit

[carguy87]

The 91-95 exhaust header from the 4.0L will fit with a 4.0L head swap.  But you will have to modify the exhaust pipe to mate up to it, and you will also have to modify the front diff bracket by the pinion that goes to the engine block so it doesn't hit.

[Baskinator]

So basically kajsdf, a 4.0 head swap in itself will require the following parts:

-4.0l cylinder head (preferably the 7120 casting off a 91-95 Jeep)
-4.0l exhaust manifold (decent stainless one can be bought off the 'bay for about $90)
-JB weld and water soluble packing peanuts to seal off certain unnecessary water jackets in the head
-new head bolts
-new head gasket, intake/exhaust gasket, flange gasket, possibly valve cover gasket, and possibly water outlet gasket

and it will also require modifications to the exhaust pipe that attaches to the new manifold. Your intake can remain the same, and the 4.0 swap by itself will give you about 40hp more, maybe up to 50 if you clean everything up thoroughly so air can flow better. A lot of the real hp and reliability comes from fuel injection, but it is not necessary for just this conversion. You can also stick with the stock carburetor if you desire, but if it's a Carter I would suggest at least rebuilding it to make sure nothing's clogged up. Not too difficult to do with a $20 kit.

All in all, it will probably cost $300-$500, depending mostly on how cheap you can get the cylinder head for. Start your search at the junk yard or the 'List site. Hot tank at your local shop would probably be another $20 or $30, machining maybe $100 or so?

The write-up on the Eaglepedia is nice, but it is way too cluttered and confusing for those just looking to do the head swap without fuel injection. It could also use some more pictures to be less confusing.

[Baskinator]

Holy cow, I can't believe that thing's not pouring out coolant without those water jackets being sealed up. They just go directly on top of the gasket.

[carnuck]

Some 4.2 blocks are wider than others (depending on the year and where they were cast) but the stroker is a 4.0L block AND head combo. No leaks to stop up!