nothingbutdarts
Well-Known Member
Awesome Joe,
4.0L HO Jeep Engine Build
- Thread starter ramcharger
- Start date
-
ramcharger
Dismember
Thanks Kim, I appreciate it. I'll let you know how it feels on the road once I renew the tags.
ramcharger
Dismember
OK here was my first impression after a quick 20 block blast around the 'hood:
I now have just about a 100 miles on it and here are my latest impressions:
The computer seems to have had time to adjust and it fires up easy when cold and settles right down to a 750 rpm idle. There used to be a lean spot at about 2000-2200 rpm that has dissapeared and the exhaust seems to have even quieted down a bit too. The alignment guy had even mentioned how smooth it idles. I had to do ball joints so it's going back to him this Sat.
The throttle is not so touchy anymore but it still takes care not to ram the slow poke in front when coming off a red light. :-D Cruising around town and accelerating to 30-45 mph takes no more than 1/8-1/4 throttle if that. Any more and I'll get a ticket. What's really interesting is when I drop the trans into 1-2 and mash the throttle on an on ramp. It pulled cleanly and shifted into 2nd at 5k then buried the 85mph speedo by 5200 rpm and was still pulling balls to the wall. It was eerie. I had to to hit the brakes hard before merging. Don't forget that this at well over 5200' altitude. I truly didn't expect that kind of high rpm performance given the cam I used and how torquey it feels around town.
I used the stock intake as I feel that Chrysler did an excellent job on the design. I did use a K&N flat filter and I'll be straight up with you all, I feel that K&N's make great "Rock Blockers" but I'd be concerned in truely dusty off road conditions. I may add an aftermarket intake tube and cone style filter so I can simply tie on a pre-filter if going off road but I doubt I'd see much of a performance gain. I may be taking this to a chassis dyno in August and that will tell the real story. I did have an intake whistle that I was able stop by simply tightening up the clamp on the throttle body to air intake. This thing really sucks, lol.
With 15W-40 and the Hughes break in cam additive I'm running 40 psi at idle hot after a 1 hr. hard drive and 60 or so on the hwy. After all the air was bled out of the cooling system and using the A/C it never runs above 185. No leaks and no drips. It hasn't used any noticeable amount of oil whatsoever. mpg remains to be calculated.
After all is said and done and with the engine about broken in and the computer working seemingly as it should, I think that a 20 hp increase is a very, very conservative estimate. MeMike may well be right as the high rpm (above 4k) performance really took me by suprise. I had driven a 2006 BMW X3 with a straight 6 up here in the rare air and this is suprisingly comparable in the power department. The throttle response is better on the Jeep (thank the fly by wire on the BMW) and the trans on the BMW is way better (mine has some serious mileage on it. I need to get it to Andrews Transmissions in the future). Although it wouldn't beat the BMW on the highway (or around curves, lol) it would certainly suprise them to hang on the on ramp with them till about 85-90.
In summation, these are the mods I made:
1. 99+ block with the main cap girdle.
2. Crank and rods set to .002-.0025 clearance.
3. MP HV oil pump.
4. Blocked decked a total of .037" for zero piston to head clearance. Total measured CR is 9.325
5. Speed Pro late model pistons with the coated skirts and thinner metric ring pack.
6. Piston pin bores set to .0007" clearance.
7. Ring gap at factory specs.
8. '92 heads home ported and milled by DC to .007" to give a cc volume of 58.
9. Heads had the valve job done by DC Racing who moved the intake seat out to the outer 1/3 of the valve seat and installed new bronze valve guide liners.
10. I shimmed the late model (99+) valve springs to '92 specs.
11. Stock Rockers with the addition of .030 Hesco pedestal shims to set the lifters at .035" pre-load + or minus .005".
12. Stock late model pushrods.
13. Fel pro .050 Head Gasket compressed.
14. Deep gasket match on both the head and intake.
15. Late model large plenum intake manifold.
16. Stock injectors. 19 lb Mustang 4 hole injectors I'm saving for dyno tuning.
17. BBK 62mm throttle body.
18. Stock airbox with K&N filter.
19. Cheap ARP stainless header.
20. Magnaflow hi-flow cat. Not so cheap, lol.
21. Dynomax cat back exhaust.
22. NAPA manifold to cat pipe. The original has a rediculously restrictive crimp in it. The NAPA part is much better but still not ideal.
23. Cloyes timing chain.
24. The weird cam with 4.2 specs but 4.0 HO lift installed at 110 degrees.
25. Hesco head bolts.
I think that's pretty much it, but if I think of something I forgot I'l be sure to add it in.
What would I have done differently?
I would've used the Lunati cam I mentioned earlier. :read2: it would have required different springs, spring seat machining, different retainers, valves and locks.
In conclusion,
All in all I'm very, very happy with this build and it seems to have met or even exceeded my goals and I see no problem with passing emissions. I can run this thing in my garage for 5 minutes without my eyes watering (don't do this at home kids....) Most of the mods are internal and the external ones all have CARB exemptions..... pretty much, lol. Like any engine recipe, I can't guarauntee the same results unless this build is follwed to the "T". Keep in mind that every block and head was cast on a different day too. Tolerance stacking is a *****. :read2:
I now have just about a 100 miles on it and here are my latest impressions:
The computer seems to have had time to adjust and it fires up easy when cold and settles right down to a 750 rpm idle. There used to be a lean spot at about 2000-2200 rpm that has dissapeared and the exhaust seems to have even quieted down a bit too. The alignment guy had even mentioned how smooth it idles. I had to do ball joints so it's going back to him this Sat.
The throttle is not so touchy anymore but it still takes care not to ram the slow poke in front when coming off a red light. :-D Cruising around town and accelerating to 30-45 mph takes no more than 1/8-1/4 throttle if that. Any more and I'll get a ticket. What's really interesting is when I drop the trans into 1-2 and mash the throttle on an on ramp. It pulled cleanly and shifted into 2nd at 5k then buried the 85mph speedo by 5200 rpm and was still pulling balls to the wall. It was eerie. I had to to hit the brakes hard before merging. Don't forget that this at well over 5200' altitude. I truly didn't expect that kind of high rpm performance given the cam I used and how torquey it feels around town.
I used the stock intake as I feel that Chrysler did an excellent job on the design. I did use a K&N flat filter and I'll be straight up with you all, I feel that K&N's make great "Rock Blockers" but I'd be concerned in truely dusty off road conditions. I may add an aftermarket intake tube and cone style filter so I can simply tie on a pre-filter if going off road but I doubt I'd see much of a performance gain. I may be taking this to a chassis dyno in August and that will tell the real story. I did have an intake whistle that I was able stop by simply tightening up the clamp on the throttle body to air intake. This thing really sucks, lol.
With 15W-40 and the Hughes break in cam additive I'm running 40 psi at idle hot after a 1 hr. hard drive and 60 or so on the hwy. After all the air was bled out of the cooling system and using the A/C it never runs above 185. No leaks and no drips. It hasn't used any noticeable amount of oil whatsoever. mpg remains to be calculated.
After all is said and done and with the engine about broken in and the computer working seemingly as it should, I think that a 20 hp increase is a very, very conservative estimate. MeMike may well be right as the high rpm (above 4k) performance really took me by suprise. I had driven a 2006 BMW X3 with a straight 6 up here in the rare air and this is suprisingly comparable in the power department. The throttle response is better on the Jeep (thank the fly by wire on the BMW) and the trans on the BMW is way better (mine has some serious mileage on it. I need to get it to Andrews Transmissions in the future). Although it wouldn't beat the BMW on the highway (or around curves, lol) it would certainly suprise them to hang on the on ramp with them till about 85-90.
In summation, these are the mods I made:
1. 99+ block with the main cap girdle.
2. Crank and rods set to .002-.0025 clearance.
3. MP HV oil pump.
4. Blocked decked a total of .037" for zero piston to head clearance. Total measured CR is 9.325
5. Speed Pro late model pistons with the coated skirts and thinner metric ring pack.
6. Piston pin bores set to .0007" clearance.
7. Ring gap at factory specs.
8. '92 heads home ported and milled by DC to .007" to give a cc volume of 58.
9. Heads had the valve job done by DC Racing who moved the intake seat out to the outer 1/3 of the valve seat and installed new bronze valve guide liners.
10. I shimmed the late model (99+) valve springs to '92 specs.
11. Stock Rockers with the addition of .030 Hesco pedestal shims to set the lifters at .035" pre-load + or minus .005".
12. Stock late model pushrods.
13. Fel pro .050 Head Gasket compressed.
14. Deep gasket match on both the head and intake.
15. Late model large plenum intake manifold.
16. Stock injectors. 19 lb Mustang 4 hole injectors I'm saving for dyno tuning.
17. BBK 62mm throttle body.
18. Stock airbox with K&N filter.
19. Cheap ARP stainless header.
20. Magnaflow hi-flow cat. Not so cheap, lol.
21. Dynomax cat back exhaust.
22. NAPA manifold to cat pipe. The original has a rediculously restrictive crimp in it. The NAPA part is much better but still not ideal.
23. Cloyes timing chain.
24. The weird cam with 4.2 specs but 4.0 HO lift installed at 110 degrees.
25. Hesco head bolts.
I think that's pretty much it, but if I think of something I forgot I'l be sure to add it in.
What would I have done differently?
I would've used the Lunati cam I mentioned earlier. :read2: it would have required different springs, spring seat machining, different retainers, valves and locks.
In conclusion,
All in all I'm very, very happy with this build and it seems to have met or even exceeded my goals and I see no problem with passing emissions. I can run this thing in my garage for 5 minutes without my eyes watering (don't do this at home kids....) Most of the mods are internal and the external ones all have CARB exemptions..... pretty much, lol. Like any engine recipe, I can't guarauntee the same results unless this build is follwed to the "T". Keep in mind that every block and head was cast on a different day too. Tolerance stacking is a *****. :read2:
fishy68
Tyr Fryr's Inc.
Man it sounds like you nailed it Joe. Always great when you exceed your expectations.
ramcharger
Dismember
I was very concerned that that the cam would fall flat past 4k. Not so. :cheers: It might be the porting, Throttle body and manifold combining to stretch out the torque curve... Maybe, lol. I still wonder what it would've driven like with the real 4.0L HO cam advanced 6 to 8 degrees.
I suppose a dyno test could be done with every little thing done one at a time including the quench I added, thinner ring pack, etc. I just don't have those resources though.
We both know that true performance and efficiency is gained as a system and that's how I tried to approach this build. In regards to this line of thinking, I feel that I left maybe 10hp on the table by not going with the Lunati cam, but I sure never expected the cam I got to spec out in the way it did either. It's like basing a build a on a factory HP 340 cam and getting a cam from the 360 they put in the little red wagon pickup.
Now I know though and hopefully this information will help those contemplating a build like this. I still have another block laying around and if i blow this one up, a stroker 4.6L will be in the works using the knowledge I gained from this build. Maybe I'll put a turbo on it too, lol. I have to wait until this thing hits 25 years old so I don't have to emmision test it.... :-D
One thing I will also add is that the distributor is sloppy by design (AMC). I understand why the later models of this engine used individual coil packs and I feel that with the correct computer, like a megasquirt, some single digit improvements could be made. If I went with a turbo, I feel that this mode of ignition would be mandatory as well as a better way of cam position sensing.
ramcharger
Dismember
Agreed and you know what I'm talking about first hand.. As it is Blizzaks or studded tires may be mandatory. Most certainly so if I decide to drop in some 3.73 gears and some Detroit True-Tracs... If it's availible for the 8 1/4.
[ame="http://www.youtube.com/watch?v=lZmsY2YvVsc"]YouTube- Exploded View - Inside the Eaton TrueTrac Differential[/ame]
cudaspaz
Well-Known Member
Awzumm, now build one for a dart and post vids, hurry up now ha, ha.
74scamp360
Junior Member
thats awesome man, great to hear her running!!!
ramcharger
Dismember
DroVal
Well-Known Member
Thanks for the link to your build. Most of the technical stuff was above my head, but I still enjoyed reading it. 2 years later, how is it doing?
Hopefully I will be able to get back to work sometime soon. I want to start working on mine. The PO neglected it pretty badly. It only has 111k miles on it and runs pretty well, but I still baby it. Considering the amount of neglect and abuse it has taken over the years, I'm too nervous to use it as anything more than a grocery getter.
Anyway, thanks for the read! Have a good one!
Hopefully I will be able to get back to work sometime soon. I want to start working on mine. The PO neglected it pretty badly. It only has 111k miles on it and runs pretty well, but I still baby it. Considering the amount of neglect and abuse it has taken over the years, I'm too nervous to use it as anything more than a grocery getter.
Anyway, thanks for the read! Have a good one!
Ramcharger,very nicely thought out build.
bad440
everything,all the time..
nice , that dog will hunt!
ramcharger
Dismember
You're welcome DroVal!
2 years later.... Runs cool, 20+ mpg on the highway if I'm not towing anything or plowing into a high headwind. Burns no oil and no oil leaks. I can easily smoke my buddies '99 V6 Tacoma light to light or on the highway. The torque curve is super flat
Thanks!
Yes it does. When I had it down near sea level I had to be super cool making turns from a stop or it would kick the rear out on dry asphalt or concrete.
MopaR&D
Nerd Member
So ramcharger is all you did to increase fuel flow the bigger Mustang injectors? I just upgraded to the APN header, later intake manifold, and bigger head pipe (I made a thread about it over at 'FJO') and it didn't pick up as much power as I expected... I think it's because I still have the stock injectors in there.
ramcharger
Dismember
Oh man, just moved pretty much this entire thread to the new "For Jeeps Only" website. That was one hell of a task. I think you're on there mopekid and I answered your question on your post, let me if I'm wrong.
escout314
New Member
Hey, I was a little curious to see how the build has continued to work. I know you mentioned you would go with the Lunati cam if you had done things differently. Besides adding the possible 10hp (+/-), what effects would it have in terms of mileage, TQ, etc? I haven't had a lot of experience with cams, so input would be much appreciated. Also, I can't remember if you were using the old injectors or the 4-hole mustang ones? I've heard of people running into starting issues with the 4-hole design is why I ask. Thanks
ramcharger
Dismember
Jeep runs great and has tons of torque right off idle. I just had the Jeep emissions checked and it passed with flying colors. This is tested on the dyno, not an idle test. The emissions guys couldn't believe it and three of them came over to talk to me. I wonder if they get a hp reading off those dynos?
Limit________________As Tested
HC 2.5000_________.2254
CO 25.000_________5.5722
NOx 4.5000________1.5838
Yes, the HC is really POINT 2254. Even if emissions are not a consideration where you live, this gives an indication of how efficient this build is. At this time I have approximately 10k on this buld and it runs great, burns no oil and gets over 20 mpg on the highway.
Even though it pulls nicely off the line (at sea level I really have to watch my throttle input to avoid squealing the tires) and pulls hard as the revs climb to about 4500, it is cam limited to about 4800 rpm. With the Lunati cam, I think I could still pass emissions and have it pull nicely to 5200+ rpm while giving up a bit of off idle response. Right now it's almost jerky off idle. Great for off road use though.
Don't bother with the 4 hole mustang injectors. It's just runs too rich on start up and it's really not needed, even with the mods I made. The stock pintle style injectors are made to whack the backside of the intake valve and the engineers knew exactly what they were doing when they designed this engine.
BTW, welcome to the forum!
Limit________________As Tested
HC 2.5000_________.2254
CO 25.000_________5.5722
NOx 4.5000________1.5838
Yes, the HC is really POINT 2254. Even if emissions are not a consideration where you live, this gives an indication of how efficient this build is. At this time I have approximately 10k on this buld and it runs great, burns no oil and gets over 20 mpg on the highway.
Even though it pulls nicely off the line (at sea level I really have to watch my throttle input to avoid squealing the tires) and pulls hard as the revs climb to about 4500, it is cam limited to about 4800 rpm. With the Lunati cam, I think I could still pass emissions and have it pull nicely to 5200+ rpm while giving up a bit of off idle response. Right now it's almost jerky off idle. Great for off road use though.
Don't bother with the 4 hole mustang injectors. It's just runs too rich on start up and it's really not needed, even with the mods I made. The stock pintle style injectors are made to whack the backside of the intake valve and the engineers knew exactly what they were doing when they designed this engine.
BTW, welcome to the forum!
abodyjoe
Well-Known Member
ahhh. now i have to read through this thread incase my boys jeep ever needs a rebuild. hell it only has 200,000 miles on it and he isn't easy on it..
ramcharger
Dismember
ahhh. now i have to read through this thread incase my boys jeep ever needs a rebuild. hell it only has 200,000 miles on it and he isn't easy on it..
Have fun with it Joe! It's amazing how long these engines will last with just a little TLC.
escout314
New Member
Thanks for the info! Another note I forgot to mention is that I'll be running with the AW-4 tranny and the jeep spends about 80/20 percent on pavement and dirt, repectively. So based on that, would you still lean towards the Lunati Cam? I know my first gear leaves something to be desired (2.80:1 or something like that), therefore a little extra torque would be nice, but having the power dissappear at 4800 rpm isn't exactly prime either.
While I was reading this thread I've seen you mention "quench" quite a few times. I understand what you did, but I'm struggling to understand the why. I guess what I'm getting at is, why take material from the block versus shaving more off the head itself?
Btw, I may be dropping in for random questions every once and awhile as I plan out this build. It's going to be quite some time before I can start, but a good solid plan doesn't usually hurt....
ramcharger
Dismember
Before I recommend a cam, I'll need to know tire sizes and gear ratio's. Once I have that, I can answer your queston.
No matter how much material you take off the head, you'll never move the piston closer to the head to acheive quench, all you'll do is increase the compression. Don't confuse compression and quench, they are completely different entities.
Ask away! That's what I'm here for.
BTW, the power doesn't just drop at 4800, and it will pull to 5200, it just flattens out after 4800.
escout314
New Member
Before I recommend a cam, I'll need to know tire sizes and gear ratio's. Once I have that, I can answer your queston.
No matter how much material you take off the head, you'll never move the piston closer to the head to acheive quench, all you'll do is increase the compression. Don't confuse compression and quench, they are completely different entities.
Ask away! That's what I'm here for.
Roger that.
Vehicle--2000 Jeep XJ, Auto, 8.25 rear
Tires--30X9.50 R15
Gears--Stock (3.55's I believe) I may re-gear to 3.90:1 if I switch to 31" tires
Gotcha. So quench....If I recall correctly, you mentioned how it helps deal with detonation. Why not do this out of the factory?
I might do something similar with the valves. I've never seen the seat moved like that before. What did that cost roughly, if you don't mind sharing? I'll be getting this done in CO
ramcharger
Dismember
It's too costly for the factory to set quench clearances so tight, that's why they don't do it.
I don't recall the cost, but I have DC engineering do all my engine work. They don't move the seat per say, but grind the valve to get the seat where it needs to be. Mandatory that you start with new valves.
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