Engine/Transmission (1994 - 1998) 24v into a 94

[Mhannink]

ok so im curious if anyone has done this? what all might be involved.



before anyone asks why i am taking out the legendary 12v and putting in the 24v, the reason is because my cousin wants my new 99 dodge ram truck and he want to keep his 12v engine. what is currently his truck will now be mine with a 24v. im gonna use it for a toy and just beat the crap out of it.



now back to the swap. the 99 is an auto and he plans on keeping it his truck(12v) is a manuel. so when we swap im gonna be putting an auto engine into a manuel truck. what will i need to get the engine running? like i said the truck is a toy and im thinking of pulling the body off all together and just building a tube frame roll cage for it. do i only need the engine wire harness and maybe reflash the computer for the manuel trans? or is there anything else i might need?

 

[JDKammin]

I am sure it will work. You can get a wiring harness from Painless Wiring.

 

[mfburns]

You might want to look into the electronics issues. The auto transmissions are connected somehow to the engines by sensors etc. to control shift points and these may need to be changed, adjusted, ... . something. Just my thoughts, not sure I am right.

 

[surfbeetle]

Since you're in California, you'll need to look at smog test issues. I have heard that they plan to test diesels. I don't know what year is the cut off date. I'm pretty sure they would not care about the newer engine in the older truck, but the other way around may not be allowed.

 

[Mhannink]

surfbeetle you have a good point but its only my cousin that has to worry and well he doesnt care so thats on him. as for the cutoff date i believe they will do opacity on all trucks which the 12v is easy enough to keep from smoking, and the new ones are the ones that are really being tested. so in all i think we will be ok, but it is a point of concern

 

[Extreme1]

Lot of work to swap those two. Start by swapping everything forward of the firewall with a wire on it. That will get the PCM (wrong one, you will need the manual PCM) and harnesses swapped but...







Wait for it... ...







The harnesses in the cab are BIG time different. Take a look at where the harness goes into the cab. If there is a connector there and they are the same shape, number of wires and the wires are in the right places, you're in. But I think the harness goes through a hole and connects to the junction block which I think is also big time different.



Park them side by side and start looking at the details, I think it's going to be hard.



Of course, your cousin could always convert the '99 to a 12 valve. He'd need a head, pump, lines, gearcase and an engine compartment harness from a '98 12 valve.

 

[dclassens]

Sell or trade your 24valve engine and trans. for a nice 12 valve motor and trans to match on ebay or similar. The cost my surprise you and the install would be a piece of cake. 12v out and your new used 12v back in. You said you wanted a truck to beat, the 12 valve engine is much more durable off road and in water/mud, plus its cheaper to tune and keep running(NO electronics). If you play your cards right you may be money ahead. this is what I would do, your new toy truck would not need to get all chopped into and not much invested.



Dave

 

[Mhannink]

Sell or trade your 24valve engine and trans. for a nice 12 valve motor and trans to match on ebay or similar. The cost my surprise you and the install would be a piece of cake. 12v out and your new used 12v back in. You said you wanted a truck to beat, the 12 valve engine is much more durable off road and in water/mud, plus its cheaper to tune and keep running(NO electronics). If you play your cards right you may be money ahead. this is what I would do, your new toy truck would not need to get all chopped into and not much invested.



Dave

if i could have things my way i would do this for it would be nearly ideal. however if we are not gonna do this swap then im selling the truck as a whole or in parts. one i need the money and the truck is in good shape. not something that should be beat. the swap might be tough i dont know ive heard it both ways from a lot of people and i am a fairly compotent mechanic. so we will see.



but dclassens your right the 12v would be better and if we do this swap im gonna run the 24v till it blows and it will i know that engine is on its way out. after which i will have more money and be able to put a nice 12v in there.

 

[Bob4x4]

In California engine swaps must be inspected by a referee station... ... ..... the swap is not very practical. Consider just selling and starting with what you can afford

The newer truck uses copletely different wiring... ... ... ... . and cluster etc.

 

[Mhannink]

bob i believe that only when you put a diesel into a gasser that it has to be inspected by the ref. think diesel to diesel doesnt matter. at least thats been my understanding. i could be wrong. as for the wiring ive never found that stuff to be very difficult plus i think that yo can get the painless wiring kits to make it work real smooth. also the only one that everything has to work is the 12v in the 99 the other truck 24v in the 94 it just has to run and thats it.

 

[Bob4x4]

Before the smog testing starts no problem... ..... after the 99 will be on the list

 

[surfbeetle]

Before the smog testing starts no problem... ..... after the 99 will be on the list

What's the cutoff year and weight going to be, anyone know?

 

[chipster]

What's the cutoff year and weight going to be, anyone know?

I understand the `98 and up diesel pick ups will be tested starting in 2010. no weight break. they will be pluged in to the OBDII port to comunicate with the state computer, have a visual inspection for ALL smog equipment, and must pass a snap test for black smoke. do not have to run on the rollers. :-laf:-laf if last vin # is even truck will be tested in 2010, if last vin # is odd truck will be tested in 2011, then every other year after that. #@$%!#@$%!

 

[surfbeetle]

So if you have a 98 12 valve with a TST plate that doesn't smoke and would pass the snap test, what would the odbII connection tell the smog tester?

 

[Bob4x4]

We are hoping the 12vers drop off since they are non electronic and not much they can scan for other than egr codes.

 

[chipster]

So if you have a 98 12 valve with a TST plate that doesn't smoke and would pass the snap test, what would the odbII connection tell the smog tester?

It would tell the tester that you do not have a 98 engine and it is an illegal swap. according to a smog referee I know, the diesel engine swaps done in 98 and newer vehicles the engine swaped in must be the same year or newer than the vehicle. same as gas engine swaps. the obdII computer will be looking for a tach signal, tps signal, and lots of other stuff thats in the computer that runs the 24v engine. things are going to get tougher to get your diesel to pass smog. It might take some thinking on the inspector if your engine is an early 98 or a 98&1/2 model. I dunno what signals the early 98 obdII would be lookin` for.

 

[Mhannink]

from what i got from the local county smog board is that the only trucks being tested are anything over 14k gvw and ive heard it has to be commercial. which who knows how thats gonna work cause in ca our trucks are commercial but not truly commercial. right now i honestly dont think anyone knows whats going to be tested and not tested. im just waiting to see when i get the stuff in the mail that says test it then i will. if we do do this swap and if they do want to test it i think we can get away with it if it doesnt smoke. if not then it will get registered in nevada.