I remember when he said that Grant :toothy10:
That's our ramcharger for ya 8)
4.0L HO Jeep Engine Build
- Thread starter ramcharger
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That's our ramcharger for ya 8)
ramcharger
Dismember
They're being good. Maxi is at my feet in the office and won't let Merlin in as usual.
Chris Andrews knows his stuff!
I just can't do anything half-***..... With the exception of the body work on the Ramcharger, lol. I'm an engine guy and I just can't bear knowing it's not what I want and/or should be. After I finish this big cocktail I have going, it's out to the truck to lift the block out, clean it up and assemble the heads and CC them so I can get an exact comp ratio. Of course I'll be checking the installed spring height and make corrections as needed.
Btw, I was going to go with KYB shocks on the Jeep but then realized that I really should just go with the Bilsteins.... They're on order. 8)
:joker: Well, I don't expect it to blow the tires off on the first run. :toothy10: It should be 10 hp stronger than stock and I'd be really freakin' really happy if it was 20 or more, but I doubt it.
ramcharger
Dismember
OK, got the heads and block back from the machinist and did some checking. I washed down, dried and threw the valve spring retainers and locks in my vibratory cleaner for a closer inspection. Note the stress cracking on the top of the retainer and the severe wear on the bottom from the spring. Also note the wear on the inside of the locks. These are unusable and are so worn that different combinations of locks and reatainers changed the installed spring height by as much as an indicated .015" of an inch. This is totally unacceptable and new locks and retainers are on order. I got the keepers from Rock Auto and the retainers from a local dealer (both should be here by the middle of next week). I can just see dropping a valve if I used the old stuff not to mention the assembly inconsistencies.
Another note on locks and retainers for these engines:
There are both early and late styles. The early style of which I'm using are single groove. These are preffered as oversize and performance valves for these engine are only availible in the single groove style. The late style are 3 groove and use a much thinner keeper. These different styles of retainers, keepers and valves are not compatible with each other! Use only 3 groove locks with the retainer specified for them and single groove locks with their matching retainers! Needless to say, you can't use a single groove valve with a 3 groove keeper and vice versa.
Another note on locks and retainers for these engines:
There are both early and late styles. The early style of which I'm using are single groove. These are preffered as oversize and performance valves for these engine are only availible in the single groove style. The late style are 3 groove and use a much thinner keeper. These different styles of retainers, keepers and valves are not compatible with each other! Use only 3 groove locks with the retainer specified for them and single groove locks with their matching retainers! Needless to say, you can't use a single groove valve with a 3 groove keeper and vice versa.
ramcharger
Dismember
Note how far the plug tip is in the chamber! Yes, these are the correct plugs for the application. Although I can imagine that a tip that far out in the chamber would lead to less emmisions and a more complete burn, I wonder if this is why these engines tend to have detonation problems under high loads like towing. Technically, the flame front should be smaller with a centrally located spark but I bet that tip gets hot man. I'm going to check to see if a colder plug is availible.
The next picture shows my set-up right before cc'ng the chambers. They all came out to 59 cc + or - a half a cc.
The next picture shows my set-up right before cc'ng the chambers. They all came out to 59 cc + or - a half a cc.
ramcharger
Dismember
The conical valve springs from early to late heads ARE interchangeable. I have reason to believe that the late springs are about 10 lbs. stronger on the seat. I have a set of low mileage springs and these look fine after a clean up.
Time to get back to work and be productive. I'm presently assembling the short block and will be cc'ng the pistons and deck. I want to get a true measured compression ratio. Stock per the Jeep specs is 8.8:1. I'm shooting for 9.5:1 but I'm hoping that with all the decking I did to get my quench where I wanted it, I don't end up with a 10.5:1 CR. Using race gas in a daily driver would blow, lol. This may end up being an e-85 build......
Time to get back to work and be productive. I'm presently assembling the short block and will be cc'ng the pistons and deck. I want to get a true measured compression ratio. Stock per the Jeep specs is 8.8:1. I'm shooting for 9.5:1 but I'm hoping that with all the decking I did to get my quench where I wanted it, I don't end up with a 10.5:1 CR. Using race gas in a daily driver would blow, lol. This may end up being an e-85 build......
fishy68
Tyr Fryr's Inc.
Good eye catching them stress cracks. Those locks look like the ones the Magnum heads use.
ramcharger
Dismember
Thanks Fishy. Interesting that you brought that up. The valve stems are 8mm. These engines actually have a lot in common with the Magnums:
They use the same valve spring shims.
They use behive springs.
They have 8mm valve stems.
They use Magnum intake valves (with the correct square single groove keepers).
They use Manum valve spring retainers.
Chambers are closed.
Intake valves are 1.92 (EX are 1.50).
Rods are 6.123" (although the factory spec is 6.123" to 6.125".... And they used every thousandth, lol).
They use a .904" lifter.
They have a 1.6:1 rocker arm ratio.
Kinda freaky.... :read2: If it had two more cylinders it would be 5.3 liters too. Each cylinder displaces .666 of a liter. Wierd. :toothy10:
ramcharger
Dismember
OK, here's a few tips. First of all, 2001 through 2002 blocks use a different rear main seal than all other 4.0's. Oddly, my block is a 2000 and uses the newer style seal. Why did they change seals and why does my somewhat earlier block use it? I have no clue. It's a Jeep thing and no one understands, lol.
Pictured below are the two seals. The earlier one is the top one with the arms on it and the later one looks more like a standard LA or Magnum seal. The part number for the early one is BS40612 and the late one is BS40183.
When installing these types of seals I always leave an 1/8" sticking up on one end on the cap and drop the coordinating end in the block so the parting lines don't match the block. Less chance of a weep that way. I always use the little plastic tab they give you when installing too. That prevents damaging the backside of the seal. Oh yeah, the lip of the seal always faces the the inside of the engine.
Pictured below are the two seals. The earlier one is the top one with the arms on it and the later one looks more like a standard LA or Magnum seal. The part number for the early one is BS40612 and the late one is BS40183.
When installing these types of seals I always leave an 1/8" sticking up on one end on the cap and drop the coordinating end in the block so the parting lines don't match the block. Less chance of a weep that way. I always use the little plastic tab they give you when installing too. That prevents damaging the backside of the seal. Oh yeah, the lip of the seal always faces the the inside of the engine.
Badart
Senior Member
Cool thread Ramcharger. I just picked up an 87 Cherokee Larado with the 4.0 and 5 speed from a coworker for $300. It runs, she parked it three years ago because of a bad power steering pump and bald tires. LOL. Pulled it home last week. When I get a chance I will be getting it up and running again. I might make a hunting rig out of it.
ramcharger
Dismember
Right on BD! PS pumps are right there in any boneyard and these are incredibly capable vehicles.
ramcharger
Dismember
There is something about a freshly machined block that just floats my boat. :toothy10: I'm a sick, sick man, lol.
I now have zero deck clearance! Well, for the most part anyway, lol. Due to manufacturing tolerances in the rods the pistons range from zero to .002" below deck. I'm glad I compensated when I gave the machine shop my specs. After the first deck to straighten it out, the pistons were a max of .033" below deck so I told my machinist to take .030" off the top.
Short block is together and ready to cc. I'm celebrating with a "Cherry Duster" in one of my old Snap-on mugs. Funny how I thought she looked a bit old to me back in the day. Now she looks HOT!!! :-D Time is a *****. :read2:
I now have zero deck clearance! Well, for the most part anyway, lol. Due to manufacturing tolerances in the rods the pistons range from zero to .002" below deck. I'm glad I compensated when I gave the machine shop my specs. After the first deck to straighten it out, the pistons were a max of .033" below deck so I told my machinist to take .030" off the top.
Short block is together and ready to cc. I'm celebrating with a "Cherry Duster" in one of my old Snap-on mugs. Funny how I thought she looked a bit old to me back in the day. Now she looks HOT!!! :-D Time is a *****. :read2:
ramcharger
Dismember
OK, happy as a pig in poop! I just did the calculations and found that I have true measured CR of 9.236:1!!!! This should run just fine with premium and .040" quench I built in! It's a hair below my target but better below than above. I mucked up my first calc and thought I had 10.6:1 and I about crapped. I found the error though (had entered the piston cc as -15 instead of +15.... )
)
ramcharger
Dismember
Now on to cam choice. I wanted to stay stock due to the computer configuration so I decided on the early cam. Here's the specs, early first.
As you can see, the early cam is hotter and that's what my computer is set for. More lift and duration. They split and dropped the duration and lift vs. the early cam to meet emission standards then kept the power up with a much improved intake manifold which I will also be swapping on with the addition of 24 lb. four hole disc type injectors from a mustang GT instead the factory pintle style. This just gives the computer more headroom to provide more fuel under demand and should give better atomization as well.
Like I said before, this is kind of like a super stock build.... The best of the best that Chrysler offered (and some Ford parts, lol) to bring out the best that this engine can offer without computer changes and a stock idling daily driver. Maybe I'll fail big time, maybe not. I've researched this pretty thouroghly so I guess maybe I'm just a mad scientist.
As you can see, the early cam is hotter and that's what my computer is set for. More lift and duration. They split and dropped the duration and lift vs. the early cam to meet emission standards then kept the power up with a much improved intake manifold which I will also be swapping on with the addition of 24 lb. four hole disc type injectors from a mustang GT instead the factory pintle style. This just gives the computer more headroom to provide more fuel under demand and should give better atomization as well.
Like I said before, this is kind of like a super stock build.... The best of the best that Chrysler offered (and some Ford parts, lol) to bring out the best that this engine can offer without computer changes and a stock idling daily driver. Maybe I'll fail big time, maybe not. I've researched this pretty thouroghly so I guess maybe I'm just a mad scientist.
ramcharger
Dismember
Oh my! Looky what I just found! I already bought a header but man oh man..... A custom exhaust would be mandatory but this is too cool! It's from Clifford...
ramcharger
Dismember
Here's the new Magnaflow high flow cat (49 state legal) and the Dynomax cat back exhaust. This should help getting the gas out and make room for more air fuel in. The SS header is in the background and that shouldn't hurt either. :read2: It's not as nice as the Clifford, but it'll do for now and everything should be pretty much bolt in as far as the exhaust is concerned. I wonder what this Jeep will sound like? I've never in my life heard a hotrod 6 cyl Jeep before.
Of course my loyal shop dog Maxi will not leave. Merlin already wanted in... :-D
Of course my loyal shop dog Maxi will not leave. Merlin already wanted in... :-D
Man Ho Man Joe =P~=P~=P~ that build is rockin right along :cheers:, I still say after looking at you valve lift and exhaust and intake up grade you will be seeing an easy 30hp gain if not more compared to the factory restricted system :-D
Dang I wish I was there :bootysha::bootysha: I see maxi:love7::love7:
I will pay half for a dyno pull 8)
Dang I wish I was there :bootysha::bootysha: I see maxi:love7::love7:
I will pay half for a dyno pull 8)
ramcharger
Dismember
Man 30 hp would be really, really nice but..... :-D
Maxi says Woof! (Hey!). She seems to be using the leg more and more although it's still kinda floppy. She hates that brace. I've pretty much given up on it. If she won't walk with, there's no point.
LOL, I doubt I could find an engine builder with an AMC 6-cyl dyno mount plate.
fishy68
Tyr Fryr's Inc.
That's a right stout cam for a stocker. Right in line with some of the old performance cams of the late 60's to 1970. No wonder those engines ran so good right off the floor. Also I bet with your compression and good quench you will be able to run on 89 octane. Possibly even 87 octane. I noticed when shopping for valve springs, retainers, and locks for my Iron Rams they listed a lot of the same parts for the Jeep 4.0 as the magnum stuff.
MopaR&D
Nerd Member
So that's why my 'new' 1993 Cherokee 4.0HO feels quicker than my friends' '97 and '00 Wranglers. And they're all stick-shift too! It's pretty surprising for 177k miles too. Can't wait to do a full exhaust, bored TB, and cold-air intake on this thing.
I'm surprised at the lack of aftermarket downpipes for these engines, the stock ones SUCK. Too small to begin with, and lots of bad compression bends...ugh. I might try to build a system with a removable section of pipe in place of the cat altogether, actually. I just hate the way they sound and El Paso County doesn't emissions-test -- yet.
I'm surprised at the lack of aftermarket downpipes for these engines, the stock ones SUCK. Too small to begin with, and lots of bad compression bends...ugh. I might try to build a system with a removable section of pipe in place of the cat altogether, actually. I just hate the way they sound and El Paso County doesn't emissions-test -- yet.
ramcharger
Dismember
Yep Fishy, that cam is suprisingly large for a stocker. In retrospect I suppose the 4.0L HO is really kinda of an inline 6 Magnum.
This thing sure didn't have any quench before, although it was fully cabable of it with those pistons and heads.
You got the good one in the good years ('91-'94) with the bigger port heads and bigger cam.
Even doing nothing at to all these engines it's suprising how quick they are. We also have OBD1 computers which are the most forgiving in regards to modifications. You are absolutely correct about that goofy downpipe. That's another issue I was going to bring up in a later installment. Borla offers a header with a downpipe but they are about 600 bucks. If I had that kind of money I'd get the Clifford and have a custom exhaust done. I'm going to either bring mine in to a muffler shop and have a real one made or make one myself. More to come on this. :read2:
This thread is waaaaay beyond me (technically LOL), but I still wanna hear it run. Nice write up and glad to see that Maxi is moving around :thumbup:
ramcharger
Dismember
Thanks C! There will be more to come this week if work doesn't get in the way, lol. Maxi's getting around just fine. Her frisbee day are over for sure but I think she'll be OK. Her right leg has become huge compared to her left. It must be her body compensating.
nice build you got going on! this thing must rip! cool parts too.
ramcharger
Dismember
We'll see how it does when it's done. I've seen reports of some guys going with aftermarket cams, exhaust, intake, stroking it out to 4.6 liters, roller rockers, etc. and only getting into the 240 hp range. Not horrible but it sure makes me think 20+ hp out of this build is optimistic. I can't really vouch for thier skills, but still.... I think the Trucks! guys only got like 133 from their stroker 4.0 HO "Cheep Cherokee", lol.
MopaR&D
Nerd Member
They must not have known what they were doing, 240 HP is what the mostly-stock strokers tend to make. Check this out:
http://jeep4.0performance.4mg.com/stroker.html
Wonder what a Voodoo (or other larger) cam, 10:1 compression, and roller rockers would do for one of the "4.6L low-buck" strokers. Wouldn't add too much cost either, if the cam had small enough duration to work with the stock injection system.
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