4.0 questions

Chrisduchene

Chrisduchene

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Hey guys I'm to to the forum I have found these forums to be a good source of information when I was building my 258 for my cj and decided to join and actually communicate. I am currently building my 1997 tj 4.0 32rh auto. I'm building a super budget MI dedicated stroker with boost coming later since I have 2 258 cranks laying In the garage a 12 wt and 4 wt but I am looking at the rebuild kits online and they are listed as 96-98 then obviously the newer ones. My question is what's the difference between the 96 through 98 4.0 internals and the more modern 4.0s?is there a difference at all or just listed that way for ease and convenience
 
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Im pretty sure 96-98 are all the same, 2000 was when coil packs were added and im pretty sure they changed the head too. But others can chime in to confirm.
 
Head, exhaust, coils, different intake. Block bolt points and accessory mounts were different to. Go check out jeepstrokers.com. My stroker is as powerful as my wife’s 3.6 jk. If you want larger valves get 5.7 early Hemi valves, they work with stock size valve springs, oversized throttle body, 2000 intake has a huge plenum that is claimed to be equal flow. The 32rh will need better internals if you decide to beat on it any. Kolene steels and redline clutches along with the sonnax valve body modifications and good accumulators and pistons.
4.0 Engine pistons and 258 connecting rods and crank can be stock part numbers but your quench height is critical. I have posted a bunch under my username, so search for me and stroker. I built mine in 2006, when fairly new, now they are not so popular much anymore . Good luck. Tim
 
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Interesting topic on which I have read some (but I am NOT an engine builder, so reader beware):

There were 4 different Jeep 4.0L heads. I think the 96-98 the Jeep 4.0L head casting was 0630. Ports were slightly different from the previous 7120 (91-95) and it has two receiver holes for two dowel pins in the block for cylinder head alignment. The 0331 head casting started in 1999. It also had the dowel pin holes (so perhaps the same gasket as 0630?) and mounting points on plug side for coil packs. It also has reputation for cracking. For that reason, some builders use the 7120 head casting for stroker motors or an aftermarket head for 99+ year blocks. Also the 7120 head is supposed to be more amenable to porting (relevant for you if you want to add boost?).

Aside from head nuances, I assume you will need a different cam and valve springs as well as bigger injectors for a stroker.

Finally, I thought boosted motors usually run lower compression ratios then atmospheric engines. Do you plan to change pistons when you add boost?
 
Thanks guys. Yes I know in 99 the 0331 heads went to the TUPY which is supposed to be the stronger one because of the cracking issues with the earlier models. The 7120 is the one that I am junkyard hunting for now because of the better flow numbers and strength. I was really curious on why manufacturers were separating the years the way that they do considering all the internals are the same. One can only assume it's for the gasket changes due to the dowel pins for the cylinder head. I will probably be doing my own porting since the port job I did on my 258 has turned out quite well. I will be going with a pretty decent cam set was flirting with saving and getting a roller set up for it but I'll probably stay with the hydraulic flat tappet due to cost. It will be some where around 260s duration with just under .500 lift at 114 lsa I'm not planning on putting different pistons in it when I eventually go to boost just going to gap the rings for it so I don't have to take it apart again. The way I'm figuring it it will come out around 9.5 :1 comp but with so much over lap in the cam it will not be nearly that high running at with only 5 to 7 lbs of boost I should be ok but I will be doing a lot more research before I pull the trigger on the boosted part.
Thanks Tim I will definitely check it out I do plan on doing a complete rebuild of transmission it's one of those things I haven't done and want to do. I was also thinking of looking for a 4x4 727 and making that work but I don't even know if they made them or were to find them.
 
For what its worth my 99 TJ Came with the 0630 head and distributor, but uses the 2000 + intake manifold.
The 0331 heads were problem children in 2000 , 2001 , 2002 sometime in 2003 - 2004
they modified the 0331 head casting to reduce cracking, ( TUPY ) Our 2004 came with the TUPY head and comes with a coil pack.
I understand your dynamic / static comp. ratio thought , but still curious about a static 9.5 C.R. AND 5 - 7 lbs. boost on a iron head.
What deck height are you shooting for ?
Are you planning on running forged pistons ?
Sounds like this could be a fun build ! , I am just curious how you are controlling detonation , fuel mapping , timing curves .
Hang in there and have fun!!!
 
And that's where I'm at. What is my deck height going to be? And thanks for the correction on the tupy head I couldn't remember exactly when it changed. But that's pretty much where I am at now is figuring my deck height with the stroker crank and rods because I want to run the 4.0 rods because they are longer and I do plan on getting custom made forged pistons. So I know I'm going to have to look at pin height and maybe even skirt length because of the internal balance and stroke length. Those are the things I have to do more research on. As for the feeling and mapping I wanted to use flying Ryan at frp with his sct tuning abilities remotely but I had placed my order for the tuner and a canned tune just to see how it was Bone stock then tune again stroked then again. With boost so I could document the whole thing. Then I joined this page and there it was him saying he has to hault things for awhile because too much work not enough time and it's not fun like it used to be which I completely understand if it's not fun it's not worth doing it just kinda screwed my plan up. So I have been thinking of going old schoolish and putting an offy intake with a holley sniper efi or an msd efi then modify an msd ignition controller to work with the 6cyl and do it all through that and I think it is doable with the 32rh auto transmission as far as I know it's controlled by hydraulics not electronic other than the torque converter lock up cylinoid. So I still have lots of planning but I'll get it figured out.
 
O and the iron head really shouldn't be too much of an issue since I am keeping the boost low and really probably doing the works to it bigger valves and porting it if I can get the air in and bk out quickly and efficiently and run good gas keep cylinder pressure as low as I can Givin the circumstances really just try and keep big spikes to a minimum should be ok
 
Chrisduchene said:
And that's where I'm at. What is my deck height going to be? And thanks for the correction on the tupy head I couldn't remember exactly when it changed. But that's pretty much where I am at now is figuring my deck height with the stroker crank and rods because I want to run the 4.0 rods because they are longer and I do plan on getting custom made forged pistons. So I know I'm going to have to look at pin height and maybe even skirt length because of the internal balance and stroke length. Those are the things I have to do more research on. As for the feeling and mapping I wanted to use flying Ryan at frp with his sct tuning abilities remotely but I had placed my order for the tuner and a canned tune just to see how it was Bone stock then tune again stroked then again. With boost so I could document the whole thing. Then I joined this page and there it was him saying he has to hault things for awhile because too much work not enough time and it's not fun like it used to be which I completely understand if it's not fun it's not worth doing it just kinda screwed my plan up. So I have been thinking of going old schoolish and putting an offy intake with a holley sniper efi or an msd efi then modify an msd ignition controller to work with the 6cyl and do it all through that and I think it is doable with the 32rh auto transmission as far as I know it's controlled by hydraulics not electronic other than the torque converter lock up cylinoid. So I still have lots of planning but I'll get it figured out.
Click to expand...
There are a lot of calculations in any correct / successful engine build ! Take your time and recheck everything a bunch of times.
Glad to hear your using custom slugs and long rods, better math can make a better engine!
My $ .02 on the fuel side of things, please stay with the factory port injection setup, find a tune builder and stay port injected.
Holley sniper is a rabbit hole you DON'T want to go down. It is typically a challenge to make it work properly on a mild SBC.
You don't want to go through all this work just to burn it down due to a fuel issue.
Have FUN and plan , plan , plan!
 
Lol thanks man yea I have a lot of planning to do but it should all work out my biggest concern is the tuning I'm a young old school guy all this computer tuning stuff is hard for me I like carbs lol but I am really going to have to stay with the injection it's going to be hard to find someone that can tune it around here but I'm sure there's someone around here that can do it
 
astjp2 said:
Head, exhaust, coils, different intake. Go check out jeepstrokers.com
Click to expand...
Chrisduchene said:
Thanks guys. Yes I know in 99 the 0331 heads went to the TUPY which is supposed to be the stronger one because of the cracking issues with the earlier models. The 7120 is the one that I am junkyard hunting for now because of the better flow numbers and strength. I was really curious on why manufacturers were separating the years the way that they do considering all the internals are the same. One can only assume it's for the gasket changes due to the dowel pins for the cylinder head. I will probably be doing my own porting since the port job I did on my 258 has turned out quite well. I will be going with a pretty decent cam set was flirting with saving and getting a roller set up for it but I'll probably stay with the hydraulic flat tappet due to cost. It will be some where around 260s duration with just under .500 lift at 114 lsa I'm not planning on putting different pistons in it when I eventually go to boost just going to gap the rings for it so I don't have to take it apart again. The way I'm figuring it it will come out around 9.5 :1 comp but with so much over lap in the cam it will not be nearly that high running at with only 5 to 7 lbs of boost I should be ok but I will be doing a lot more research before I pull the trigger on the boosted part.
Thanks Tim I will definitely check it out I do plan on doing a complete rebuild of transmission it's one of those things I haven't done and want to do. I was also thinking of looking for a 4x4 727 and making that work but I don't even know if they made them or were to find them.
Click to expand...
727 does not have optimal 1st gear 2.45 where the 32rh is 2.72-1... grand wagoneers had the 727, I have one in my garage. 32 also has lockup torque converter, don’t know if 727 had any lockup converters.
 
Chrisduchene said:
And that's where I'm at. What is my deck height going to be? And thanks for the correction on the tupy head I couldn't remember exactly when it changed. But that's pretty much where I am at now is figuring my deck height with the stroker crank and rods because I want to run the 4.0 rods because they are longer and I do plan on getting custom made forged pistons. So I know I'm going to have to look at pin height and maybe even skirt length because of the internal balance and stroke length. Those are the things I have to do more research on. As for the feeling and mapping I wanted to use flying Ryan at frp with his sct tuning abilities remotely but I had placed my order for the tuner and a canned tune just to see how it was Bone stock then tune again stroked then again. With boost so I could document the whole thing. Then I joined this page and there it was him saying he has to hault things for awhile because too much work not enough time and it's not fun like it used to be which I completely understand if it's not fun it's not worth doing it just kinda screwed my plan up. So I have been thinking of going old schoolish and putting an offy intake with a holley sniper efi or an msd efi then modify an msd ignition controller to work with the 6cyl and do it all through that and I think it is doable with the 32rh auto transmission as far as I know it's controlled by hydraulics not electronic other than the torque converter lock up cylinoid. So I still have lots of planning but I'll get it figured out.
Click to expand...
You want something like a crane cams 753901 cam, just enough without too much. Oh and your 32 has solenoids that are controlled by the pcm. Mustang injectors and adapter plugs help with the stock pcm.
 
Yea I was reading about that but I don't know which 24lb injectors to get or were to find the adapter plugs to be honest I haven't looked too hard either I've been specing out the rotating assembly and head once I have that where I'm happy with it I am going to do head and fuel I'm going to get the 01 and up intake from junkyard I'm also thinking about making my own map voltage adjuster as well I'm cheap and like junkyard and diy I save the money for critical parts I know that the 32 had the lockup converter cylinoid that could be switched to togle pretty easily if I were to go with a different fuel delivery system I did not know it had others though though it was hydraulic so I learned something
 
Not sure the year break, but the cam retainer style changed around 2000'ish. While you can convert one style to the other, they are not compatible as is.
 
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