Engine/Transmission (1994 - 1998) Building a Monster Mudder

[Morphious]

Hello all, I just bought a beat up old 96 12 valve auto 4x4 extended cab long bed off of craigslist today for 800. 00. The whole truck is very rough and the injection pump is completely out of the truck and sitting in rusty pieces in the passenger floorboard and missing pieces, I figure I won't be able to use it as a core for another injection pump, just how life goes sometimes.



Anyway, on to my questions. I'm new to the 12 valve world, I've been driving my 24 valve for the last 10 years and 250k miles, so I'm pretty familiar with the cummins diesel overall and turned alot of wrenches on them.



My goal for this truck I just purchased is to build a diesel mud racing truck, it will be purely an off road vehicle and not driven on the street at all. i will be running 37" to 38" mud tires, but the class I'm going to be running in is class 4, which has truck running 900 hp big block chevies and the like. They are fast and pretty wicked.



Basically I'm starting from scratch on the truck and will be pulling the motor and gutting the interior of the worn out truck, shortening the truck to a shortbed and possibly putting a regular cab truck on it to reduce weight and length even further. I'll have a locker in the front and probably a spool in the back running the 3. 55 gears it currently has in 4wd low range. The auto trans is going to be gone through with all new clutches, valve body and torque converter.



Question 1: 47RE, who makes a manual valve body for this transmission? For the races, do you use a converter with a stall? If so how high? The mud racers like my little brothers truck runs a 3500 rpm stall (way to high for a diesel).



Question 2: What are the things I need to look for when tearing down the engine? I'm planning on tearing the top end down to check the cylindars and looking into getting it o-ringed while it's apart. (I know about the KDP and will be doing that to it. )



Question 3: Racing against trucks running 900hp bbc's (naturally aspirated, gas only), what would you think hp wise I'd need to shoot for to compete with them?



Question 4: Engine mods, what are the various go fast mods that can be done to a 12 valve?



What am I looking at parts wise? Injection pump, injectors, injector lines, o rings, cam, turbo, possibly water/meth injection... ?????



Yes, I will have various gauges installed in the cockpit (for you guage nazi's).



Exhaust will be run out the hood, rear ends will be trussed, front links will be replaced with hiem and dom tubing, ladder bars built for the rear, also looking into remote resevoir shocks and other suspension mods. Fuel tank will be removed with a fuel cell in the bed, battery relocated to the back of the truck... .



Still in the early planning stages.





Any pointers or help would be appreciated.



Morphious

 

[Missouri Mule]

Question 1. Don't know but DTT,ATS,SunCoast,Goerend are the top four aftermarket trans builders for diesels. From what I've read low stall convertors put out more pressure at low rpm and that is where you max torque comes in on 12 valves. Of course it depends how you set your engine up.



Question 2. Get a factory service manual (Geno's Garages sells them).



Question 3. Depends on what you want to break. But I think 600 hp would match a 900 hp gassers torque. Oh yea a thicker head gasket and three piece exhaust manifold.



Question 4. A 215 hp p7100 injection pump , big inejectors 370hp or stage 3,

up grade the turbo you mite want twins but I don't think you will need them. Upgrade the intercooler. Cam plate, you can get the p7100 worked on to get even more horses.



Members with more know how will chime in. I'm still running a stock truck.

 

[Morphious]

Yeah, I've pretty much ignored the auto transmission wars that went on here, so I'm not all that familiar with them as I've driven an nv4500 for the last 10 years and just followed the clutch wars.



I plan on getting a factory service manual, I've used the heck out of the one for my 24 valve.



I'm used to breaking things, I was thinking along the lines of 600 hp from a diesel would get me competitive, there are alot of other things I've got to do besides the engine work to get it to the ground and usable during a full run. The pits I've seen so far can be thick soup, very rough and deep (not worked with a dozer), thin and fast...



Tires, weight transfer, and a big helping of luck play a large part of it.



I'm not going to run twins, only a large single turbo. I'm playing russian roulette with the rules to start with as they only cover gas engines, they allow turbo's and fuel injection if the vehicle comes with it from the factory in the classes I'm going to run, so I'm using that to get a diesel in it. I'm sure if I actually spank one of the fast trucks, the rules are going to be changed, so it's going to be interesting being the first diesel to race in the association.



Thanks for the info,





Morphious

 

[Hammer]

Morph...

Glad to see your still hanging around... .

You still down in the Charleston area as I was down there not long ago with the truck and figured I'd see your ride slipping around somewhere?. I seen many Cummins rides but missed yours.



Anyway. . I will try and answer some of these for you... ... .

Question 1: 47RE, who makes a manual valve body for this transmission? For the races, do you use a converter with a stall? If so how high? The mud racers like my little brothers truck runs a 3500 rpm stall (way to high for a diesel).

There is a shop up here in my area who can do a manual valve body for you. The name is "East Coast Diesel" and they do alot of custom application diesel automatics. Their number is (717)861-7525 and ask for Ladell or Lamar. They are very busy right now and if they do not answer leave a message and they will return your call.

Question 2: What are the things I need to look for when tearing down the engine? I'm planning on tearing the top end down to check the cylindars and looking into getting it o-ringed while it's apart. (I know about the KDP and will be doing that to it. )

Check the cylinder bores for the crosshatch and see if you notice excessive blowby of the rings. If it was me I would buy a rebuild kit and while it was down I would throw some new main and rod bearings in it to be safe.

Question 3: Racing against trucks running 900hp bbc's (naturally aspirated, gas only), what would you think hp wise I'd need to shoot for to compete with them?

You should have yourself as close to them as possible HP wise. Because they are not going to be rpm limited like you so anything you can do to gain rpm, would be a big help. Over 600 at least and you may want even more to ensure the power to gain quicker times in the pit.

Question 4: Engine mods, what are the various go fast mods that can be done to a 12 valve?

Many... .

Depends on how deep your wallet is and how big of a budget you have to build this truck. Head work to ensure the rpm you need is a must and I would venture to say a roller cam would be a big help.

What am I looking at parts wise? Injection pump, injectors, injector lines, o rings, cam, turbo, possibly water/meth injection... ?????

All of the above and you will need to bullet proof the driveline also. Also of note you should try and loose some weight to even the playing field a bit as you will have more nose weight than a truck equipped with a BBC. The lighter you get the faster it goes through the mud pit and the easier it is on parts.

Yes, I will have various gauges installed in the cockpit (for you guage nazi's).

Only one gauge needed for this deal... . Corsa Intellidash.

It also has the ability to add a data logger if you want it too.



Mud racing is fun if you can get your rides bugs worked out early. Remember,because of the added weight of the diesel you will want to loose some from elsewhere so your racing on the same field as the gassers. Use a small charger which lights fast and moves a good amount of air so you can gain the needed wheel speed to fly over the pit. The key in mud racing is not how much power you have to trod though the mud its how much power you have to gain the wheel speed to stay on top of the mud and get to the other side as quick as possible. I had fun while I did many moons ago with my Jeep and it is very addiciting... ... . Andy

 

[Morphious]

Hey Hammer, I've been pretty absent for a while, the job I have has me travelling for work every week, so I maybe put 80 miles a month between 2 trucks and a harley. I moved back west last fall, and split my weekends in San Antonio where my RV and kids are and Oklahoma where I grew up and bought 120 acres last year. Still need to build a house and a shop. I'm going to try and get the truck ready for the 2010 season, but alot depends on what happens in the next few weeks, just got a 30% pay cut on the travelling job, so I'm looking for another job right now.



I'll try to give them a call, I just needs a parts source as we will rebuild everything ourselves.



I'm planning on doing a full rebuild kit since it's got 330k on the motor and am unsure of how it was treated. I'll know more when I get it here and can start tearing into it.



I was looking at either a 4k or 5k gsk, I plan on putting a cam in while I'm at it, who makes a roller cam, I don't think I've seen any of those listed on the various sites. If running a 5k gsk, what else needs to be addressed to turn those rpm's?



Right now my wallet isn't very deep, but I'm selling my 1ton CC chevy duramax and getting rid of it's payment and help free up some cash. I've almost payed off my RV in the last 6 months only about 4k left to pay on it now.



For the drive line, I'm looking at a spool in the rear with 35 spline axles, a locker in front with a cad delete and 35 spline axles and beefy ujoints.



Weight wise, the truck will be pretty much stripped, interior wise all that will be left is the steering wheel and dash (have to have the dash in it), but it will be gutted, all the accessories will be gone. the truck will be atleast shortened to a shortbed truck, but also considering dropping a regular cab on it and going shorter to help lighten it up. I'd really love to find an old dodge weapons carrier body to put on it and go even shorter and lighter as it's a single thickness cab insteady of the multiple layers. I'm still looking for one.



I'll look into the Corsa Intellidash, haven't really started researching much yet as I just finally found a truck after looking for about 6 months.



when you say use a small charger, are you talking along the lines of a hx35 or 40, or along the lines of a phat shaft 62?



My little brother started racing this year with the truck he built over the winter, here is a link to the website I put up for thier group, Tall Boys Racing he's running a hopped up 383 in an 83 chevy pickup. I've helped him on it quite a bit over the last year when I was home. He's pushing around 550 hp and is ranked #2 in the class 3 and on the lower end of class 4. He wants me to run in class 4 and not in class 3 with him... I thought that was narrow minded of him.





Morph

 

[Morphious]

Brought the future mudder home Sunday

I picked the truck up Sunday from the boob that had it in Southern Oklahoma, ended up getting it for 700. 00 due to the owner not getting the title updated, I'll have to do that sometime in the future if I ever decide to make it streetable, doubt it, so I'm not worried about it.



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Right now I'm working on a list of parts and things I'll need. I've decided to run in Class 2 to start with, I won't mess with shortening the truck and some of the more expensive modifications needed for class 6. This will allow me to get my feet wet and go from there.



Right now I'm looking at a 3" suspension lift and a 3" body lift. Replacing the inner axles on the front dana 60 with 35 spline axles and deleting the cad unit with either a spool or locker in the front.



On the rear dana 70, what is the spline count on the axles? I want to get a spool for it as well, but all i can find for gears less that 4. 10 is for a 35 tooth spline and on searching I've seen it could be either 32 or 35.



I've got to pull the engine, trans and transfer case out and go through each of them.



The bumpers/tailgate/bed liner/bedrails will be removed, interior will be gutted, AC/Heater and all thier parts will be removed.



Fuel tank will be replaced with a fuel cell, will a normal fuel cell work with diesel, was looking at either a 5 or 10 gallon aluminum fuel cell from Summit with foam in it, does that cause a problem with diesels?



Airbags, horns, and anything else I can think of will be removed.



Who makes a good auto floor shifter with a reverse pattern for the 47RE?



Well, that's the update for now, going back to cateloge shopping and product reviewing.



Morphious

 

[hsmith]

700 bucks and it runs??? What a deal. Good luck with your toy venture.

 

[BDaugherty]

You've covered a lot of ground with this discussion so far. However, here are a few tips from someone with a lot of mud time:



Solid recovery points front and rear. Getting stuck or broken happens to everyone.



Make sure you have all the shielding on your transmission such as dust covers, guards, and such. The flywheel/flexplate will fill your starter with mud awful fast.



Maybe not necessary for mud drags, but great for longer runs is an extra windshield washer tank parallelled with the stocker. Can't drive if you can't see. A squeege (?spelling?) works like a champ for cleaning the worst of it from the windshield and your wipers will clear the rest.



Get the air intake into a protected area. (For competition only, the cab works great). Your mechanical fan can turn the whole underhood area into a mud car wash. You don't want your engine sucking mud into the air filter.

 

[Morphious]

No, it doesn't run, the injection pump was off and dismantled with pieces missing or rusted as the boob left it out where it got wet.

 

[Morphious]

BDaugherty, yes, I'm ditching both front and rear bumpers inplace of steel pipe with anchor points. This past season while my brother has been running his truck we've see trucks get sideways in the pit, loose front wheels due to ball joints, flip upside down, and about anything else you can think of, oh and a factory bumper with grade 8 bolts getting ripped off when it was being pulled out.



All shields will be in place for all the components.



The pits are 100 to 200 yards long, not enought time to even think about hitting a switch to wash your window. We wash them in the pit between runs.



I haven't figured out where I'm going to put the air filter yet, were running outer wares on my brothers truck right now and it's doing pretty good with that, but I know with a diesel, there will be alot more air requirements.



Morph.

 

[Morphious]

mudder update

Thought I would give an update on the mud truck:



Haven't done much, been looking for parts and things like that mostly, got a diesel compression test kit from Matco the other day, need to test all of the cylindars to see what kind of shape they are in, will determine if I'm tearing it down first thing or putting that off for a bit. I'm still looking for an injection pump want a 215hp pump, will see what I can find out there. I need to order a timing kit from snap-on as well.



I have decided that the truck is going to be rebodied with a 46 power wagon body and shortened about 5' from the extended cab long bed that it is now. Here are some picks of the power wagon parts i'm buying:



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with the change to running an old power wagon body, I'm going to relocate the radiator to the bed of the truck, and switch to a water to air intercooler, intercooler will be up front of the turck in the nosecone, with the radiator and ice chiller in the bed of the truck. This will also keep the radiator, w/a radiator and transcooler out of the mud as much as possible and move some of the weight to the back of the truck. Battery and 10 gallon fuel cell will also be in the bed of the truck.



That's it for now, kinda slow going right now, just started a new job that I don't have to travel with, so I am in the process of planning out my house/shop building to get it started and get my own place built.





Morphious

 

[MoparBob]

I have decided that the truck is going to be rebodied with a 46 power wagon body and shortened about 5' from the extended cab long bed that it is now.

That is a great idea! I love the old power wagons!

 

[dseabaugh]

for $800. 00 you stole it even if it isn't running. Overall it looks pretty decent.

 

[Morphious]

I ended up getting it for 700. 00 bucks in the end, so it was an even better deal. All the sheet metal will be for sale once I start disassembling it, including the intercooler, fuel tank, etc that I won't need. Need to pay for other Mods. I'm planning on running a water to air intercooler on it due to space limitations in the front of the truck, will put the intercooler up front and the radiator, ice box and pump in the bed with the radiator.

 

[Morphious]

Time for an update on the birth of a monster mudder. She breathed life today, if somewhat anemic. I picked up a used p7100 pump from Nathan Foster here on the TDR, it's a 913 215hp pump. I put my stock 180 pump fuel plate in it and finally found and purchased all the bolts and nuts needed to get the pump installed. We got the air out of the injector lines and it started. Here is what I'm seeing, and what we diagnosed. The first 3 cylinders have good pressure to the injectors, when you crack the lines, fuel sprays out, on the back three injectors, it just dribbles out. I cracked the main fuel line into the p pump and fuel just oozes out from the fuel line while cranking the truck, we thought it might have been air locked, but to me this points to the mechanical fuel pump being bad. We could manually push the primer button and get more action out of the cracked line than with the engine cranking the pump. From this we are thinking it's the mechanical fuel pump, does anyone have any other ideas? I'm planning on getting a new mechanical fuel pump or an electric pump and a new fuel filter for it. Anyone agree or disagree?



When you put a load on the engine, it acts like my 24 valve does when my electric fuel pump is shut off, it will idle fine, but when you give it fuel it starts stumbling.



I've picked up the body for the mud truck and once I get the truck running, I'm going to drive it into the shop and start tearing off the body, and begin the rebuild on the truck to fit the 46 power wagon body.



Now that I have the body, once I fit the cab on, I will know exactly how much room I have for the radiator and intercooler, I know the stockers won't fit, so I'm either going to have to relocate the radiator to the back of the truck and run a water to air cooler or something along those lines. Does anyone know of a reputable place to get a water to air intercooler at a reasonable price? I've seen the ones on Frozenboost.com and thier other websites and have looked at spearco intercoolers as well, any help in that department would be appreciated.



Morph

 

[Missouri Mule]

Getting fuel to the cylinders seems more like the injection pump (p7100)!:{



Fuel pressure going to P7100 should be above 20 psi at idle another words you need to do fuel pressure test (20 psi to p7100 is minimum).

Probalbly the reason it is just ozzing fuel when cracking the supply line to p7100.

 

[Morphious]

I'm not ready to say it's the injection pump, especially after seeing how little pressure there was on the fuel line to the pump. My 24 valve with an electric fuel pump puts out 13 to 15 psi and it will spray all over the place when I crack the fuel line to bleed air out of the system, the 12 valve, had very little pulse and more or less just oozed, so I think it's a pressure/volume thing for why the back three injectors don't have enough to popoff. We ran a test and cracked number 4 cylindar on the truck with the mechanical fuel pump providing fuel, it was just oozing out around the line, but when we started using the primer bulb, it increased the amount of fuel coming out at the injector, so to me that points at a problem with not enough fuel being supplied to the pump.







Morph.

 

[fest3er]

Another Chat Freak rises from his slumber.

If it runs roughly or barely at/near idle in neutral but smooths out at higher RPM (1500-2000), the problem is most likely the fuel pump. If it never smooths out, the fuel pump might be sucking wind I mean air. Shoot, rig a temp tee-line from your 24V lift pump to the 12V p-pump. Or use any available pump that'll produce 15-25 PSI. It doesn't have to be plumbed in perfectly; a presidential solution is adequate for testing purposes. Pressurize the fuel tank to 10-20 PSI air. If it runs better with an external pump/pressure, you'll know where to look for the problem.

 

[Morphious]

Yo fest, long time no chat. You are correct, it runs like caca at idle, but if you keep the R's up, it smoothes out and will run at around 1500 to 2000 rpm. We thought about hooking a line up from my 24 valve, but it was just too much of a pita. What is the pressure that is needed for a 12 valve? The fuel system is going to be changed out to run from a 10 to 15 gallon fuel cell once I start building the truck up. I'm running a holley blue on my 24 valve and it's lasted quite a long time, it puts out about 13 to 14 psi on it, would it put enough out for the 12 valve?





Morph

 

[fest3er]

Yo fest, long time no chat. You are correct, it runs like caca at idle, but if you keep the R's up, it smoothes out and will run at around 1500 to 2000 rpm. We thought about hooking a line up from my 24 valve, but it was just too much of a pita. What is the pressure that is needed for a 12 valve? The fuel system is going to be changed out to run from a 10 to 15 gallon fuel cell once I start building the truck up. I'm running a holley blue on my 24 valve and it's lasted quite a long time, it puts out about 13 to 14 psi on it, would it put enough out for the 12 valve?





Morph

Yup, that sure sounds like a wore-out lift pump. Same thing mine did. But in my case, the new pump sucked a hole in the rusty feed line, making it run lousy at every speed.



As you know, it ain't the angle of the dang... errrr it aint so much the pressure, it's the flow. So your target power will dictate the minimum flow. Considering my phlegmatic '98 will run nicely with a wore-out lift pump and a semi-collapsed filter what's got 1/8" of asphaltene covering it, I think your Holley Blue or a spare OEM 24 valve lift pump should work very well for early testing, until you trip over the right solution in that dark corner of your shop or it rolls off a shelf and conks you on the head. Or to use other words, use just about any reliable fuel/lift pump, because selecting and installing the optimal fuel/lift pump can be deferred until just before you really need the extra fueling.