12valve to replace 24valve

[DieselTim]

Ok, who can tell me how much trouble and what has to be changed to replace a 98. 5 24valve engine with a 94 12valve. I am fed up with computer and vp44 problems and I found a 12v cheaper then a replacement vp44. So, is it something that can be swapped or is it just a dream that will become a nightmare? Both of the engines are 5sp manual. So, what kind of a job is it?



Thanks, Dieseltim

 

[HAnderson]

Where was a white 99 1 ton at may madness with a 12 v in it. Some one must know whose truck it was. H Anderson

 

[bmoeller]

Don't know if it will matter to you, but the '94-95 engines have the small fuel injecton pump. Will take more parts to get the same results as the newer engines.

 

[Got Smoke?]

Don't know if it will matter to you, but the '94-95 engines have the small fuel injecton pump. Will take more parts to get the same results as the newer engines.

Nah... ... . just grind the plate flat and keep an eye on the pyro! :-laf

 

[Todd G]

Be aware that this swap would be illegal in any state that does emmissions inspections, or might do so in the future.

 

[bmoeller]

Nah... ... . just grind the plate flat and keep an eye on the pyro! :-laf

Just depends on how carried away he wants to get. :-laf Won't get 300hp from justa #0 plate in that thing. If that were the goal.

 

[Evan A. Beck]

Ok, who can tell me how much trouble and what has to be changed to replace a 98. 5 24valve engine with a 94 12valve. I am fed up with computer and vp44 problems and I found a 12v cheaper then a replacement vp44. So, is it something that can be swapped or is it just a dream that will become a nightmare? Both of the engines are 5sp manual. So, what kind of a job is it?



Thanks, Dieseltim

"Swap" is a relative term. Yes, you can put the 12V in there, but getting it all to be factory-looking again is what takes a lot of time and effort.



We've done it to our '02 shop truck. Automatic trans.



Was it a lot of trouble? YES. Do I recommend you do it? No, unless you want to spend countless hours making it perfect!



It all depends on how "factory" you want it to be. Our truck still has all the goodies like cruise control, AC, and everything else it came with. I had to spend a fair amount of time building a custom wiring harness for the engine, so everything would still work. Factory dash and everything else is still in the truck. The wiring alone took several days, but it all turned out great, and looks like it came from the factory. The TPS was tricky, but I managed to get it within limits.



Since you have a '99, it uses the crankshaft position sensor for the tachometer. So you'll basically need to have a 24V block with the CMP sensor in it, but with a 12V head, pistons, and everything else. Of course, this is assuming you want the factory gauges and charging system to work. Without the tach sensor (CMP sensor) working, you will not have a lot of functions related to the PCM. These include cruise, charging, AC, grid heater operation, and a few others.



This project is going to be expensive, especially since there's a lot of little things you don't even realize you need until you get the engine in the truck. I don't even want to know what we have into our truck in terms of cost... It's a lot, however we did do a custom built engine, along with some other things. Even in your case though, you are still going to be into it a lot of dough.



If I were you, I would spend the money on a new VP44 and a DD cam. Install a 12V mechanical lift pump, and be done. I doubt you'll ever have any more VP44 failures. We have done a ton of cams/lift pumps, and its the best way to eliminate fuel system problems. You'll spend way less money, and still have a truck you'll be able to resell to someone who needs to be emissions-compliant.

 

[ronco]

Would the 24 to 12 conversion be worse than a P pump conversion?





Ronco

 

[Evan A. Beck]

Want easy? Buy a 12V truck. Thats the easiest, and probably best, way to do it! :-laf

 

[BTighe]

as much work as it must be that 02 12v is one awsome truck. got some power too. i heard that the p-pump conversions have there set of problems too though.

 

[Evan A. Beck]

as much work as it must be that 02 12v is one awsome truck. got some power too. i heard that the p-pump conversions have there set of problems too though.

Yeah, our '02 does pretty well. A couple weeks ago, it ran an 11. 96 @ 112, and we even had it detuned a bit, and didn't have all the extra weight stripped off. Should be mid to low-11's before too long. Then there's the sled pulling... Its a jack of all trades I suppose. Best dyno run to date was 817/1515 on N2O. 630/1220 on #2. Single turbo, daily driver truck. Tows regularly!



#ad




P-pump 24V trucks (P24's) have their share of issues too. They are very hard to get dialed in just right, but they can make some decent power. They run pretty hot though. IMO, the 24V head works best and is most efficient with the VP pump and mechanical lift pump. Plus, its just more reliable, and parts are readily available. With a P24, break an injector line or something on vacation towing your fiver and you're screwed!

 

[DieselTim]

swap

Ok, to update. I found out that the donor truck is a 96 4x6 so, that means the engine is just like my 2500 auto that I am driving now. I am getting the whole truck so if I need any wiring or the pcm from the donor then I will have it on hand. Both the donor and the 98 are 5spd trucks and the donor has only 150,000 the 98 had 185,000 so I guess less mileage on the donor engine should be a good thing. Most of the body had been sold but it is still a rolling truck less transmission and transfer case. All I needed was the engine and wiring so Oo. for me.



The more I learn about this swap the better it sounds.



I did get back my ECM from Cummins yesterday but they couldn't tell me anything useful. Anyone want to buy a used 24v?



Dieseltim

 

[Evan A. Beck]

Why not just keep the 96? Get some new body panels, paint, etc... Probably be cheaper. If you had a '01 or '02 truck you were doing the conversion in, it would be easier. '98-'00 will be more work. Just don't forget the tachometer issue (charging system, etc).

 

[DieselTim]

Sure, I wish it was as easy as fixin the 96 but, the regular cab 12' frame truck has a broken frame rail and it was just patched back together just so it could be sold for parts as a running truck that could be driven up on a trailer. It had a 12' dump and it was overloaded so now it is just for parts.

I really do like my 98. 5 quad cab, I love that fact that the doors open for easy access to the back seat. I almost pulled the engine from my 96 2500 quad before I found this junked one. I went ahead and rebuild the auto transmission in my 96 and will drive it till I get the 98. 4 built.



So far I haven't had any post for not doing the swap. I see no reason other than some electrical thing that will have to be worked out. So, I am really leaning for the Go button on this project. I think it may be the best anwser yet, to have the easy of a 12v and the rear opening doors of the 98. Just wish I had known more about the vp44 troubles, I would have sold it right after I got the new transmission in it, and kept looking for a 98. 4 12v from the factory.



Oh well live and learn.



Dieseltim

 

[Evan A. Beck]

It's not just electrical. You'll need the tone wheel on the crankshaft in order to get the tach signal to the PCM. Make sense? So what would work is the 24V block and crank, with 12V pistons, head, etc. That way, you'd have exactly what you need, including a working factory tach!



We had another weird one in the other day... Guy took his '95 truck, and put a cab on it from of a '99. Presto! Quad Cab 1995 truck! I was pretty surprised to see it. Looked like stock too, but definitely a lot of work.

 

[Got Smoke?]

We had another weird one in the other day... Guy took his '95 truck, and put a cab on it from of a '99. Presto! Quad Cab 1995 truck! I was pretty surprised to see it. Looked like stock too, but definitely a lot of work.

I've love to do that! Oo.

 

[CumminsBu]

Why not call the guys at www.scheiddiesel.com they have a kit to install a P7100 on the 24V? My $. 02

 

[Reb.B]

I put a 12v in my 99. The reason a went with a 12v was because it was going to cost me $80 to run 4300 rpm in a 12v, and $2,000 to run 4300 rpm safely in a 24v. The way to do the conversion on a standard shift truck is to go with a 98 12V wiring harness and 98 12V PCM. Its really an easy conversion. I think its a lot easier than doing a 24V p-pump conversion. The cheapest thing to do is sell the truck to somebody and buy a 98 12V truck. In an auto conversion, the 98. 5-2000. 5 is fairly easy to do, but 2000. 5 and above in a real pain. I think it was Evan i taked to up in Washington that had the trouble with the cam pos. sensor. Its so hard to get right. And if you do the 98 12 harness conversion on a 2000. 5 and above truck, you loose your tack (unless you get 12v balancer and pick up) and you have to change the Govenor Pres. sensor or it will go into limp mode. I love my truck now, its very reliable, makes good power, and you can add 120 Hp on a 12V with "0" money. Since then when i buy trucks, i just buy 98 12v's and 2003 and above. I got my whole family into 98 12v's. They are reasonable, reliable and they look and feel good. The next conversion i think i'll do next is put a 2004. 5 engine in my 99. They make unreal H. P. and torque with no injectors at all. I can't wait to do it.

 

[bluthndr]

I did almost the same as what you did. All totally done maybe $4K - including the engine. You are already ahead of the game since you have a truck. PM me and I will help you with anything I can. I still use my stock V10 dash and other than the ABS and brake light, it works like factory. I think it is worth it. Mechanically, it is a bolt in. Wiring wise, it is close to bolt in if you have the factory harness and/or a Chrysler service manual. Just let me know.

 

[DKarvwnaris]

It's not just electrical. You'll need the tone wheel on the crankshaft in order to get the tach signal to the PCM. Make sense? So what would work is the 24V block and crank, with 12V pistons, head, etc. That way, you'd have exactly what you need, including a working factory tach!



We had another weird one in the other day... Guy took his '95 truck, and put a cab on it from of a '99. Presto! Quad Cab 1995 truck! I was pretty surprised to see it. Looked like stock too, but definitely a lot of work.

If I remember right, The tac sender from the older engines will work, you just have to modify the singnal and connection. A friend I knew has done this a few years back. Why use the 24 valve block? It is known to problems as well, not just the fuel system on them.



The cab swap is the easiest solution, but not easy either. Unless you swap out the dash and harness, you'll still be splicing and modifying the electrical.

I am looking for a quad cab for my '96 to do just this myself. My only concern is the VIN# issue, I like my 96 as it has a replacement value on file with the NADA for insurance. The majority of 98 or newer cabs I have found are salvage title only. I may end up looking for a 1/2 ton 2wd quad cab truck and just selling it with my old cab on it after I get the VIN#'s etc swapped back and forth to make it legitimate as possible.