6 weeks ago I bought a 4.0 head/exhaust/mpi unit from a '98 Jeep Cherokee off of E-bay, and the guy finally got me the head. It's going on my '80 258. I was not happy on the delay, but oh well, it's here. I took it to my machine shop 15 minutes after UPS dropped it off and he says it looks good. Going to grind my valves and clean it up for me ($90 - thought that was good).

I know there has been discusion on how to fill the water jackets, epoxy vs welding. He thought the welding would be dificult due to the cast iron. Any welders out there have some tips? Why doesn't the head gasket cover these up?

If I can borrow somebody's web page, maybe I'll do a write up on it plus my trials puting the MPI on as well.

Now I won't be able to sleep at night - dreaming of making the swap!

My girlfriend said if I spent one more dime on my Jeep she would leave. Man I'm going to miss her!

You got head from UPS, that you bought on E-Bay? Wow, never even THOUGHT of that one...[img]/wwwthreads_images/icons/wink.gif[/img]

'83 CJ-7 nothing original but the tub and axle tubes

Tippy, welding cast can be a difficult task. It can be done, but it would involve preheating your head and some real careful monitoring of the heat input while welding, and controlling the cooling after the weld. Also after your passes the welds need to peened to relieve the stress so you don't crack the head as it cools. You need to make short welds. The rod has to be nickel rod. One other problem that you will likely encounter with a head is the fluids that have gone into the pores in the cast. The head will look like it is clean and dry, but when you weld, the heat will bring the fluids out of the pores creating porisity in your welds. I think you would probably have better luck with the epoxy. It is likely if you welded the head, you would have to have it surfaced after you are done. Does anyone make a kit that has a head gasket that will block the passages?

Cage Up, Wheels Down
Jeepfiend
All my Jeeps are in pieces! Except for one!!

the guy that has prolly done as much of this as anyone
is on jeepboard -name's gabe. i believe clifford sponsors
him. he say he uses a copper weld. i am a welder and am still trying to figure that one out. it sounds like it was not a big deal. people say to put "a little" epoxy in the ports. that's prolly why they all end up leaking.
then i hear the actual epoxy is a problem.
i did the exact same deal as you on ebay. i got a '97
with 15k on it and will be damned if i want to go through
the entire welding/remachining deal if i don't have to.
that's why i bought THIS head. what i am going to try is block filler from summit. i am going to tape off the ports
and kinda "flood" the whole area about 1/2" or so thick.
i already cleaned the internal contact area and primed
with that serious rustoleum rusty metal primer.
i am going to do the filler this weekend, maybe the rebuild a week later. i bought a '97 intake, but am using the 258
intake with a carb to get it all dialed in and checked.
ssoooooooooo..... i am the new guinea pig, and if anyone's interested, i'll let ya know how it looks so far......

when in doubt.........
empty the magazine.

OK, guys...
First of all, don't make the mistake of another member here who's machinist flooded the jackets with epoxy ... the dang thing ran so hot he had to replace it!
Plus, I'm not so sure primering is where it is at ... I've never seen it instructed to use primer with DuPont Liquid Steel. Primer is relatively soft.
Metal impregnated two part epoxy grabs hold of roughed up raw metal extremely well ... and probably much better than having a primer involved.
I do like the tecqnique some have used of beveling the deck edge of the jackets so as to create a larger plug 'head' that will help prevent the head gasket from pushing in the plug on torque down.
I also recommend using the biodegradable type of packing styro packing pellets to stuff in the jacket areas under the plugs. You can determine this type of pellet by dipping them in water ... they disolve almost instantly.
This prevents the heavy liquid epoxy from filling/coating the internal head jacket areas which will prevent good hot iron to coolant heat exchange.
As to a 'special gasket' ... there are no corresponding openings in a 4.2 or 4.0 block that would line up with the twelve outside triangular water jacket openings in the HO head. There are no corresponding holes in a 4.0 gasket either.
The reason for even messing with pluging these is due to the close proxmity of these openings to the edge of the block's deck ... some much more than others.
After trial fitting the head to the prospective block, many have opted to do nothing to the head due to their having 1/8th inch or more gasket seat area between the jackets and the block's deck edge.
As to welding, both Clifford and Hesco (and probably Advanced) weld the jackets to eliminate any of this type of problem of arising in their products.
Welding is the best way, no argument.
I know from experince that that Hesco uses a filler rod that can't be color distinguished from the surrounding jacket metal after re-decking to clean up the welds which leads me to believe they do not use a copper alloy rod.
Bottom line ... it's still the best bang for the buck of any Jeep I-6 mod.
Especially when combined with fuel injection.
The major web articles on this swap are listed here ...
http://monsterslayer.com/jeep/40Head/40Head.htm
http://homepage.mac.com/jefe/4to42.html
http://www.off-road.com/jeep/new/40conv.html





JAF
http://www.monsterslayer.com/jeep

I did this swap on my dads motor and did not use anything to fill the water jackets. So far I have not noticed any leaking but I am keeping a close eye on it just in case. If it does start to leak I will probably try using a 2 part epoxy to fill the holes. To me welding it is the last option because I do not have the "know how" and I dont trust most of the Yahoos around here to do it.

I'm a Dapper Dan man!!

When you said "beveling the deck head of the jackets to create a larger plug head" do you mean that after filling the hole you pushed the epoxy into the head a little bit (beveling it 'up') creating a little pocket between the plug and the motor?

Thanks for the links, I had all but one of them printed off.
I also think I am going to avoid welding them at all cost. It just sounds to risky unless you are set up for it.

My girlfriend said if I spent one more dime on my Jeep she would leave. Man I'm going to miss her!

No, tippy ...
The idea is that you do not want the 'squish' from the gasket to press so hard on the flat surface of the plug that it breaks and caves into the jacket.
So you want to take a burr to the sharp edge of the jacket right at the flat surface (deck) of the head.
Sort of like why you flair a hammer's handle with a wedge after you place it into the hammer head.
You widen the top (deck side) of the jacket so it is harder to push the epoxy plug into the jacket.




JAF
http://www.monsterslayer.com/jeep

i have seen pics of where someone made the holes that needed to be filled round (probably with an endmill) and pressed little freeze plugs in there. this sounded like an excellent idea to me! matt

Jaffer, I think I am catching on, but I had to have a picture to see it. I drew this one up - please take a look and see if I am on the right track. It's pretty tough, but I think it should be clear enough. I like that freeze plug idea, and I'm going to talk to my machinist about it.


My girlfriend said if I spent one more dime on my Jeep she would leave. Man I'm going to miss her!

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