From 24 valve to 12 valve

[Greenlee]

97 auto trans truck like Paul is looking at would have a 180hp p7100 so would have static timing, if you get a 96-97 with the 5speed and 215hp p7100 it retards timing some as rack travel increases(giving it more fuel), up to about 4°(if I remember correctly) retarded from whatever the static timing is set at.

 

There are no fuel pumps other than the one that is mounted on the engine on a 12v.

what kind of fuel pressure do you have to be concerned with? it must be low compared to the needed pressure of a 24 valve. So there is no need for an after market lift pump or mechanical lift pump at all. Are there any upgrades at all you can do with the fuel pressure on a 12 valve?

[bjytech]

The ppump actually likes more pressure than the vp44, with my upgrades I have my pressure set to about 30 at idle and see up to 50psi when above 2000 rpm.(it will suck down to the 20's when getting on it though since I just have the stock lift pump still)

On a basically stock truck though idle pressure should be around 25 psi and 30psi at 2000 rpm.

The overflow valve on the return line coming out of the injection pump is the most common reason for fuel pressure dropping on 12v's due to the spring getting weak over time, all it takes to fix it though is a trip to the hardware store to get a spring and some time to tune the length of the spring to get the pressure back up to spec. ( There's something I should write down to do a article on)

Most people say after market fuel pumps arnt needed on the 12v till 500hp.

[98whitelightnin]

When I got my 12v it had 7 psi at idle, I put on the tork teck adjustable ofv and it went up to 30. The stock lp was leaking so I put new o-rings in it and never could get it to prime and start again. The new Fass is supposed to be set at 47psi but my fp gauge only reads to 40psi and it stays pegged.

[Greenlee]

The ppump actually likes more pressure than the vp44, with my upgrades I have my pressure set to about 30 at idle and see up to 50psi when above 2000 rpm.(it will suck down to the 20's when getting on it though since I just have the stock lift pump still)

On a basically stock truck though idle pressure should be around 25 psi and 30psi at 2000 rpm.

The overflow valve on the return line coming out of the injection pump is the most common reason for fuel pressure dropping on 12v's due to the spring getting weak over time, all it takes to fix it though is a trip to the hardware store to get a spring and some time to tune the length of the spring to get the pressure back up to spec. ( There's something I should write down to do a article on)

Most people say after market fuel pumps arnt needed on the 12v till 500hp.

very informative bjytech, I am baffled on the amount of pressure the little 12 valve pump puts out. Are you running a special pump to get up to 50 psi? I think I will enjoy the 12 valve once I start learning more about it and what to do. I don't know if the automatics would outrun a 24 valve stock but the one I am getting surprises me on how quickly it moves. It has to have some mods or something done to it considering it's only 180 hp.

[Greenlee]

Don't know how I copied the same post twice, sorry.

Edited July 2, 2015 by SLT5Spd99

[bjytech]

I just have a stock cummins replacement on it, my old original one was ticking so I put a new one on it to fix that but after taking my old one apart all I think it needs is a new return spring to get rid of the tick. Some say the lift pump direct from cummins has a stronger return spring in it than one from dodge but I don't have any proof to back that up. (the return spring is what does the pump stroke to pressurize the fuel)

[Greenlee]

I just have a stock cummins replacement on it, my old original one was ticking so I put a new one on it to fix that but after taking my old one apart all I think it needs is a new return spring to get rid of the tick. Some say the lift pump direct from cummins has a stronger return spring in it than one from dodge but I don't have any proof to back that up. (the return spring is what does the pump stroke to pressurize the fuel)

I just looked at a FASS system after market lift pump for the 12 valve, I have been looking at anything I can find on the 12 valve. My engine looks like it would cut you with all the lose paint chipping and curling up every where. I have a lot of cleaning to do first. I'm supposed to sit down with the owner this Monday and get the scoop on the transmission and the engine. I know the Cummins Diesels have a good number on torque but you would think it would take more to pull a 40 ft 5th wheel from coast to coast. I'll find out soon enough because down the road i plan on pulling one smaller, somewhere around 32 ft. Is your sled puller a daily driver? My 24 valve get around 19 mpg in town and 24 mpg on the road empty. Any idea on what a stock 12 valve automatic might get? Any books or DVDs on 12 valves that explain it all?

[bjytech]

My truck is my daily driver but u like to play with it in the workstock pulls. I can't speak for the autos but with my truck i usually see around 19mpg.

[Cowboy]

The stock mechanical lift pumps are hard to beat.  They generally last 300k if there rest of the fuel system is healthy.  Yes, the new lift pumps do have stronger springs.  Here is one I sourced that is a little stronger still 975-1 Valve Spring.  The advantage to running a stiffer springs is being able to run more pressure, with more flow.  Here's a writeup a friend made that is very informative http://www.cumminsforum.com/forum/94-98-performance-parts-discussion/1622154-d89s-super-fantastic-fuel-system-escapade.html.

 

I'm not that great at keeping track of mileage, but the 12V and 24V get about the same.

 

The P7100 isn't very picky about pressure, On the one truck, I ran it with air in the fuel and 0- 3 psi fuel pressure for at least 3k miles.

 

There is no DVD or Book that I know of, however if you have questions, I am more then happy to answer them best I can. 

 

As for making a stock truck reliable, just hit the KDP, and make sure the stock fuel system healthy and you're golden.

[Greenlee]

Well I am back. My wife and I moved to a new house, no internet since my last post. I am sorry for not being able to respond back. My 24 valve is gone and My Laramie SLT extended cab Ram Dodge 2500 12 valve Automatic stock with a factory Limited Slip and only 230,130 miles showing. It is quite and smooth. Transmission shifts good. Zero to 60 mph takes about 2 minutes, lol. No, it isn't that bad but man it is slow compared to the 24 valve. The only issue I have had is a shudder that started in Reverse with my wife driving and continued in Drive. I had her pull over to look at the tires but no problem so we drove on. It reduced in magnitude the more we drove. I drove it yesterday and there was just a little bit of shudder when backing up. I have a new dash with all new A/C components and blower motor. A/C compressor has been rebuilt I don't think the KDP has been addressed yet. The ride is worlds apart between my prior 24 valve and this one. Same color and trim as the one I had. I need to fix the seats, the rails don't work well at all on either side. It should last a long time, so I need to start reading and learning about 12 valves. A new user name is in order while I am at it.

[Greenlee]

The stock mechanical lift pumps are hard to beat.  They generally last 300k if there rest of the fuel system is healthy.  Yes, the new lift pumps do have stronger springs.  Here is one I sourced that is a little stronger still 975-1 Valve Spring.  The advantage to running a stiffer springs is being able to run more pressure, with more flow.  Here's a writeup a friend made that is very informative http://www.cumminsforum.com/forum/94-98-performance-parts-discussion/1622154-d89s-super-fantastic-fuel-system-escapade.html.

 

I'm not that great at keeping track of mileage, but the 12V and 24V get about the same.

 

The P7100 isn't very picky about pressure, On the one truck, I ran it with air in the fuel and 0- 3 psi fuel pressure for at least 3k miles.

 

There is no DVD or Book that I know of, however if you have questions, I am more then happy to answer them best I can. 

 

As for making a stock truck reliable, just hit the KDP, and make sure the stock fuel system healthy and you're golden.

Thank you Cowboy, I am certain I will be throwing questions your way. Stepping out for a min. I'll check the links out when I get back

[Greenlee]

This 12 valve has never seen 2 stroke oil mixed in the tank. I need to find out if it's the same ratio as the 24 valve. I have read some good articles from Mopar1973 but I don't  know where you draw the line and not use it for a diesel engine. Any body out there use it on a 12 valve since the pump is mechanical?

[bjytech]

I put a quart in sometimes, I noticed it quieted the pump down a noticeable amount.

[Greenlee]

I put a quart in sometimes, I noticed it quieted the pump down a noticeable amount.

You don't use it all the time? Or do you use on a schedule...once a month or once every six months? I have been looking at some upgrades on the P7100, simple items but I might be dragging the horse ahead of the cart. I would like it to go a little faster than it is but I don't want to destroy anything in the process. The engine compartment is bad, not so much on grease but paint flaking off every where with normal dirt and grime. Looks like the power steering might have a small leak but it is clean on the drive way where I park it. Got to figure out what the shutter is in reverse and drive. It's faint compared to when it first started. The owner told me this trucks sits for months at a time before he starts it or uses it. Maybe it just needs to be ran a little and I need to check all the fluids. Man, no doubt you have a pulling machine, Tell me how you shift out under a load of a sled?

[bjytech]

I just tend to forget about it really, I like running for how smooth it seems to make things.

I don't know the autos to well but since it does it in both forward and reverse I would think it could be from the torque converter. I'm sure other with more knowledge in that area will chime in.

The pulls I've done so far my truck was right around 350hp so its not that powerful, shifting really isn't possible when pulling with a manual, I just put it in 4wd low range in 3rd gear and let her rip.

[Greenlee]

I just tend to forget about it really, I like running for how smooth it seems to make things.

I don't know the autos to well but since it does it in both forward and reverse I would think it could be from the torque converter. I'm sure other with more knowledge in that area will chime in.

I am thinking the same on the transmission, all I know is it was built better than stock with a shift kit but the torque convertor is stock. I hope it's something simple and cheap to fix right now until I see how my budget is going on our new home. It's been a long time since I experienced this type of shutter. Who knows, it might keep going for a while.

 

I didn't have that 3rd gear start in my head at all knowing you couldn't shift fast enough pulling a sled. What does someone do that only has 2 wheel drive and a manual?

[bjytech]

I've only seen one 2 wheel drive truck try to pull that I can remember, all it did was a one wheel peel at the start line, if it had a limited slip differential it might have got going but i don't know.

[98whitelightnin]

I have seen a two wheel drive Dually pull the sled about a foot. Gotta have a ton of power and the right tires to move the sled with 2wd.

[Greenlee]

I've only seen one 2 wheel drive truck try to pull that I can remember, all it did was a one wheel peel at the start line, if it had a limited slip differential it might have got going but i don't know.

I do have a limited slip which is good in case I should try a sled pull. How much weight and how far can you go till the bottom falls out?

 

I have seen a two wheel drive Dually pull the sled about a foot. Gotta have a ton of power and the right tires to move the sled with 2wd.

I can picture why it works that way now, 4 wheel drive is a must for this sport. I've watched sled pulls on You Tube and now that you mention it I don't remember anything except 4 wheel drive trucks competing. I noticed a fuel controlling device made by Performance Diesel or somebody that you could control the fuel with a turn of a dial and another lever that slides right to left to control the smoke. Have you seen anything close to this?

.

[Cowboy]

 

 

I noticed a fuel controlling device made by Performance Diesel or somebody that you could control the fuel with a turn of a dial and another lever that slides right to left to control the smoke. Have you seen anything close to this?

.

 

Yes, but there is a new product that's about to hit the market, and I think it's worth waiting for.