Does anybody here run a 4.0 Head on a 4.2?

GrEmLiN

GrEmLiN

New member
I know there's plenty of other threads out there covering the topic, but I'm wondering if anybody here has personally done it.

Did you fill in the extra coolant passages yourself with the recommended foam packing peanuts / JB Weld or did you have a machine shop do it with block filler while it was in for a valve job?

Do you run a carburetor or the 4.0's MPFI? I like my carburetor right now.

Any ignition upgrades or modifications done?

Cam swap at all?


Also random but does anybody here have sway bar disconnects that they made themselves? Can you post pictures? I'm gathering some ideas and would like to see what else is out there / what you used for hardware.

I hope this thread blossoms into something informative and not another slew of pock shots at me because I don't have money to piss away on my Jeep. "Just buy them they're $100 for discos" that $100 could go toward filling my tank and maybe buying me lunch in the same afternoon... Ridiculous $4.139/gal and rising down here.
 
No info on the Head/intake issue.


But the swaybar disco's are not rocket science.  If you are mechanically inclined and can fab just copy the JKS or RE Disconnect design.

The hardest part will be finding/fabbing something to use as your bushing.

Hell, if I can get around to it and swap mine out you can have my old ones. (Just don't pester me if I never get around to swapping them...  hahaha  :wink:)  I have a brand new set of JKS Disco's I need to install...
 
Well most people use cheapo pins from home depot or something. If I did it that way I would use a grade 8 bolt and grind off the threads then drill a hole through it. (I know, less talking more doing. Weather...)

What style do you have can you show me a link? That's the only thing I'll pester you for. lol
 
On the same page.  

http://forum.northeastjeep.org/index.php?topic=27109.0

But I dont think it would be worth sticking with a carb after doing all that work.  I thought about it in the past in my CJ but ended up swapping a 360 in instead
 
I run permanent sway bar disconnect, threw mine in the dumpster.  Even spring over I like the way it handles with no sway bar or track bars. 
http://www.jeepstrokers.com/forum/viewtopic.php?f=6&t=24
 
GrEmLiN said:
What style do you have can you show me a link? That's the only thing I'll pester you for. lol
Click to expand...

Mine are similar to the Rubicon Express Disco's only they separate from one end not both.
 
Dude : I did the head swap. Would I do it again ----- NO !  Yes you have to close off the 12 water jackets or rely on the gasket to stop any bypass. It helps if your engine has the 1/2 in. head bolts. Dont plan on using your intake or exhaust . Things just wont line up and you will have to rely on the bolts to hold the parts in place not just tight. I built a complete Clifford Performance engine and his spec sheet is awsome. 230 HP/ with 360 lbs Ft torque @ 3200 rpm . The engine feels like a V-8 . I run a 390 Holley and put in the off road parts and spill tube. The carb works fine if your touching the pedal,just touching it will keep it running. This winter its apart and Im doing the Holley Projection 2-D throttle body 670 cfm stand alone computer. For 1000.00 Clifford will make you 4.2 head just as good as a 4.0. The secret is the 2.02 intakes and 1.94 exhaust valves. His cam gives you 80%  at 3300 rpms but will rev to 5200 and go flat. I thought The head being free it would be cheaper. But with all the machining I had done it came out about the same and then I had to buy an intake and header so in my opinion , Have your head reworked and save so coin. Is the engine strong ? I just cant get over how much torque it has and when on the street you can have some fun with it also.  Frank
 
That's amazing and I'm aiming for horsepower numbers like that WITHOUT the price tag. I'm not spending $1000 on a 4.2 HEAD when the 4.0 is more than adequate and I paid $40 for the one I have. I can get a running V8 for $300!

I guess I'm asking the wrong crowd. I don't have deep pockets even though I'm from one of the wealthier areas of the nation.

I guess ill just figure it out as I go. I need a new machine shop though, mine is about to close down.
 
The cheap way is not always cheap and just because you can get things to work doesn't mean its the best way.

There are some very intelligent people with the experience your looking for, that for some reason still choose to answer your dribble. listen to what they have to say or stop asking.
you keep asking for everyone's opinion on everything and then say your just going to do it the way you want.so do what you want and stop asking. 
 
Well BigDaddy gave you a pretty damn good response including telling you WHY the 4.0 head on a 4.2 even starting with a FREE head wasn't worth it... Apparently you chose not to read that part?

He's telling you it'd be CHEAPER/Better to re-work your existing 4.2 head, not go the way he went (And where YOU are going)... On top of what he said you'll already be +$40 in the hole since you paid for your head and his was free...


  That's Called Comprehension 101 bud!
 
I actually bought a 92 Cherokee , took what I needed and sold off the rest. In my mind it was still free. Im understanding that if you do the head swap and nothing else , there will be a breathing increase that you will feel. Building the engine as I did required 60 thou off the deck ,100 thou off the valve spring seats. Yes the seats ! His springs wont have the clearance if you dont and push rod and or valve spring bind would have happened. I love the motor but even he suggests staying with the 4.2 head and putting in the huge valves. His cam is the power of this swap and Id recommend any if not all his products to anyone !  FjR68
 
Gremlin : If you look at a Golin engines specs, its the only other way to get close to the numbers your looking for. If I had zero decked the block I could have matched the Goalin  specs. If you look at where peak torque and horse come into play you will see that this engine is a much more usable In our play ground than the Goalin ! You have fast toys. Whats the saying ? Speed cost money , how fast do you want to go. I built a reliable I-6 that beats most V-8s in the spec column .  FjR68
 
This debate and dogpile of ideas and personal experience is why I posted this thread. After reading so many magazine articles and forum posts over the years saying how easy the head swap is I've never heard of some of the aforementioned problems. Like valvesping or pushrod bind never came up before.

I'm not saying I'm set in my ways I'm just saying what I had intended to do and am looking for more input. No need to bite my head off Alan, but you're just doing you duty I guess.

While I eventually would like to hit those numbers and eventually will build a stroker or a V8, doing things in stages seems like a great way to go. A quick valve job is all I want and to bolt it on. I have a big carb ill stick with it and carburetors are still very practical for the time being. The manifolds will all line up and with a 4.0 YJ downpipe my exhaust remains the way it is.

That's what I intended to do... I'm not building an engine here. Just a 4.0 head, valve job, head gasket, timing chain and camshaft kit (including pushrods and lifters and springs) is what I had in mind ultimately for my 6 without actually building an entire engine.

Am I missing something here? Where's the $1000 4.2 head or Golen Engine coming in at?
 
If your just doing the head swap as I said you will feel an increase . Dont count on your intake bolting right on and using the 4.0 exhaust is good. Most of my expense was extensive head machining because I was building to spec. Along with his cam kit which is pushrods,valve springs, lifters ,so all would match. Just bolting on the head without decking and the rest of the goodies isnt that big a deal. Id start looking for an intake. I have a 390 Holley all jetted and upgraded to an Avenger status if you interested. FjR68
 
My 500cfm holley 2bbl on the factory intake should be more than adequate.

I need to reread the above post by bigdaddy because I read it quickly at work on my phone.

Whatever I guess my way is wrong and I won't do it... I'll keep the 4.0 head as a spare and just keep driving my POS.
 
PICT0011.jpg

That cost me about 500 bucks, includes the wideband o2.
 
Making big power isnt all that in the world of jeeps. If you are looking to swap heads and do valve jobs, you should spend your money on something else, because putting it into a jeep is a waste.

You have to ask yourself, Do I wanna go on trail rides and crawl over rocks and splash through mud, or do I wanna drive down the street pounding pavement, and smoke some 16yo kid driving his mommys car at a stoplight.

I think as long as your motor runs, leave it alone! Just spend your money on maintenance to keep it running to get on and off the trail, because guess what? 500hp at the wheels maybe awesome, but you bust a drive shaft on the trail, and your getting towed out by my 4 banger...
 
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