Looking for advice/comments for Cummins conversion

[mrpbody]

Hi Gang,

I’m a newbie to this site and excited as ever to be a member. Oo.





I have just purchased a 1985 D300 Crew Cab with the sole intentions of doing the Cummins conversion to it. I've always admired the Dodge/Cummins truck and I’m excited about the opportunity to own/build one. I have been a Mopar nut for years, but this will be my first Diesel truck.



My plans are to convert it to a Dually and leave it a 2x4. I am looking for advice, comments, and criticism on what combinations (engine/trans/other parts - interior/exterior) work well for this conversion. I plan on hauling or pulling heavy loads and some times it will consist of driving across country.



I have just started following the forum and it looks like the first gen. 12V would be the way to go for this task, but I have not determined which trans to use as of yet, because I’m not sure if the firewall is an issue for the clutch system or if the automatic transmissions of those years are worth messing with.



To start off with while I’m looking for a donor truck, besides the intercooler addition in the 91 models, what is (if any) the difference between the engines in the years from 89 to 93 and will the parts interchange from year to year?



Any and all your comments will be helpful.



Thanks, Marty

 

[BV]

The 89-93 engines are all basically the same but HP ratings are different and they added the Intercooler in mid 91. Most, if not all parts should fit between the years.



With that said, is there a reason you would not want a 94-98 12 valve?. The 96-98 Dodge with Manual transmission and P7100 pump has the highest HP ratings and are dirt cheap to turn up if you want more ponies. Upgrades for the 89-93's with rotory (VE) pump are pretty limited from what I can see.



Transmission - I'm in favor of a manual trans and would go with a NV5600 first or the NV4500. I'm sure a guy could make a newer automatic work with a little bit of wiring and a pcm to control it. Don't think I would bother with the older automatics - Maybe someone that has a slush box with chime in.



Exterior/Interior - Owners pick. I think that I read a guy took a mid 85's CC and put the interior and wiring of a 92 into it so he had as the diesel information on the dash. Can't find that again so we will call it a rumor right now.



Sweet conversion - Keep us posted and take lots of pictures.



Later - Marty B.

 

[mrpbody]

Hey thanks for the info, as I mentioned I am a newbie and I didn't think the newer 12V's would work in place of the older ones. I thought the electronics were all different and it would have been a real hassle.

I have been trying to find any source of info along with this forum about these engines and what will swap and what will not. If it were a big or small block, I could throw something together in a jiffy.

Thanks for your help,

Marty

 

[Philip]

The pre 91. 5 model nonintercooled engines have larger dia injectors in them. The heads were noted for cracking on these model engines. In 91. 5 when they went to intercooler the injector dia was made smaller to stop the cracking problem.



94 and up engines don't need electronics on them. The P7100 only uses one wire to supply power to pump like the VE series does. So the year you use isn't much of an issue. If your not going to turn it up and run mostly at stock levels. Eather generation of engine will do fine for you.



On the 85 your working with it has no electronic's to speak of. It uses mostly direct reading sending units to monitor everything. You could even use the coil + wire to fire your injection pump. So electronic's is your call. You could use the later diesel truck wiring harness to get the indash message center. Or stay with the older setup and not even worry about using the PCM.



As far as trans you didn't say if you wanted stick or auto. If going auto I would recommend a trans with a lockup converter. If you go with a 518 at least replace the stock converter with something better. The stocker is loose from Dodge. Most of the trans companys talked about on here have better converters with lower stalls.

 

[mrpbody]

Philip,

I didn't mention which trans to use because I am not sure what the automatics are capable of today compared to then. If I remember correctly they have a reputation of failing and the overdrives seemed to burn up, and I do realize it could also be operator error, but as I mentioned, I will end up pulling or hauling heavy loads and just don't like doing things twice. So what I was trying to do was find other owners and get some feedback.



As far as the motor, I do plan up putting different goodies into it and turn up the pump. I'm a guy, it's a requirement for us to fix things that are not broke.



Have you done a cummins conversion into a non-cummins first gen truck?

I'm curious as to the engine/trans mounting points. Is it all fabriction or has somebody found a bolt in kit yet?



Thanks for your advice,



marty

 

[John - K5AWO]

Just for curiosity's sake, why do you want to build up an older Club Cab pickup? Is it just nostalgia for the body style? Buying a 94-98 truck would be a lot easier, and easy to improve on.

 

[Philip]

For the swap just use the mounts from the 88 to 91 series of 1st gens. Around 91. 5 I think the frame was made taller. So the mounts might not fit into the earlyer frame section.



If you plan on bombing go with a P pump engine. It will turn up a lot easyer than a VE pumped engine.



Towing heavy I would recommend going with the NV5600.



I haven't done a swap like this. Here is a thread with some reading in it.



https://www.turbodieselregister.com...hreadid=43806&highlight=crew+cab+cummins+swap



TDR member Thierry has done a Ramcharger swap. If he doesn't catch this thread and post some info. Send him an PM.



Crewcabdiesel has done this swap also. Do a search of his user name.





John he is building a crew cab.

 

[Proram]

Conversion

Heres a link to one i'm doing, it's a 75 Crewcab Daully 4x4 once was a 440 auto now a 93 5. 9 w/ an Nv4500 conversion and a NP203 Tf case.



http://board.moparts.org/ubbthreads...030881&page=3&view=collapsed&sb=5&o=7&fpart=1



Scott @ RDP

 

["Mad Max"]

Conversions galore...

Hi Marty - I think we have pm'd back and forth, I think about suspensions and other conversion stuff. But, if not, then I'll tell you what I'm doing - might help out.



I have a thread titled the 'Big Honkin' Project from Hell', and basically I'm also taking an '85 D350 crew cab dually (360, 4-speed) and converting to a diesel and a whole host of other ridiculous upgrades, including transmission upgrade, 4x4 conversion w/ mated np205, 4-corner air bags in lieu of springs or coils, onboard air, front and rear 4-link suspension, and a bunch more. I'm blending my '85 crew cab and my '93 CTD club cab into one truck. Two trucks enter, one truck leave.



The list of tasks includes:

- '93 CTD swap (with several engine modifications in the process)

-- Head, cam, turbo and exhaust upgrades including exhaust brake

- '98 47RE auto/od install (DTT-built, bulletproof)

-- Dual-mode lock-up converter, manually or automatically operated

- '92 np205 mated transfer case

- GearVendor overdrive - mated to back of np205

- '79 Dana 60 dually front diff w/ 4. 10's, lock-out hubs, and discs

- '01 Dana 80 dually rear diff w/ 4. 10's, lim slip, ABS, and discs

- 4-link front and rear suspension fabrication

- 4-corner air bag suspension

- On-board air w/ electric compressor

- '93 dash and electrical harness swap into '85 cab

- '85 firewall replaced with '93's firewall

- Complete restoration of all sheetmetal, dash, interior, chassis



It's a lot of stuff, but I'm taking a year to do it, and when done it should be able to haul my 28' enclosed car hauler and all the gear I can find to anywhere in the world, providing there's roads. Plus, I'll be able to go off-road for camping, RV'ing, etc. It is being purpose-built to be an incredibly powerful and strong rig while being very comfortable to drive. It should haul down the highway like a dream. I'm fully expecting to spend around $20k to do it, but I'll have a rig that will out-tow just about anything and be a lot more capable. There are a lot of other litle upgrades that I'm doing, but I'm keeping them sort of a secret. I plan to drive it to PDR next year for their as yet unannounced dynofest '05 for its debut. Plus, we're planning a road trip to the Mopar Nats in '05, so we're gonna have a ball, and I'm driving the hell outta this thing.



Anyways, just thought you might be interested in my little Monster Garage project. Any questions or insight please drop me a line. I'm doing a lot of experimental stuff, but it looks like it'll be pretty good stuff in the end.



Laters,

- Sam