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Discussion Starter #1
Welcome to the build thread for my second cummins conversion. Following is a basic outline for this new build:

The purpose:
An economical, dependable, long-lived vehicle, with the ability to transport people and/or cargo, as well as tow a trailer if needed. This rig is for my wife, and she of course wanted an automatic, as well as something that she could get our kids in and out of easily(4 boys so far). She liked the express vans, so that is what we looked for.

The Project rig:
A '99, 1 ton, 15 passenger, Chevrolet Express Van. It has 241,000 miles and a blown 350 engine, It also has the 4L80E trans, and came with brand new Firestone TransForce HT's, the interior is a little rough, but the body is in really good shape overall. my wife also liked the maroon paint instead of the regular white that most of these vans have. The tires are worth almost what I paid for the whole van, so we were off to a good start.


The Donor rig:
A 92 D350, auto, extended cab, 2wd, just over 300,000 on the odometer (the PO said it hasn't worked for a while), The trans was bad (the PO said it was shoved in reverse while going about 60):nuke: It was starting to be parted out, so the drivers door was already gone, as well as the rear axle, otherwise the truck was complete. The engine that is in it came out of a 93, and has an estimated 190,000 on it. The pump has never been touched, all the caps are still on the screws and none of the tamper paint has been broken:D


The plan:
Mount the 93 cummins to the 4L80E with a straight cummmins to gm adapter, build a spacer to bolt between the chrysler flexplate and a gm flexplate to keep the torque converter in the stock position, fab my own engine mounts, build either a microcontroller (parrallax Basic Stamp), or a PLC (programmable Logic Controller), to monitor throttle position, rpm's, and boost, to output fake signals to the original gm pcm to control the tranny, as well as keep all the stock gauges working.

I Finally got started on this conversion a couple of weeks ago, The link to all the photo's is:

http://s761.photobucket.com/albums/xx256/plcnut/99 express 3500 Cummins conversion/

Photobucket did not keep any of them in order... sorry.. I just took lots of pictures as I went, Some of them are only so I could look back and know what sensor each of the wires went to.."a picture can be worth a thousand words" they say
I will try to keep the album updated as I progress.

I am currently waiting on my conversion adapter to show up so I can get the final measurements for the flexplate spacer.

Will keep you all posted.. hope you can enjoy this build, and God Bless!
 

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this seems to be a really good idea to put a cummins into a chevy express... i've already seen some older chevy vans being repowered with 4cyl perkins diesels in brazil but they were converted to manual transmission as avaliable in brazilian and argentinian diesel chevy trucks...
 

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Discussion Starter #4
Well, I've been too busy to spend much time working on my project, let alone on here, but progrss is as follows:

The first adapter plate I bought (eBay) was actually a Jaguar to gm tranny adapter,
(the guy thought it came off a 4bt) so I got that one sent back... Then I got an adapter from a guy on this forum, it tilts the tranny but that won't hurt anything in this application, and it also came with a flexplate that is about 1" thick so that I don't need a wave ring. I got the engine plate installed on the engine along with the flexplate and starter about a week ago...
Finally today I got to do a test fit into the engine bay, the engine is about 32" tall from bottom pan to the top of the valve covers, but the engine bay is only about 30" from the cross member to the top of the dog house opening, so I cut out the lower radiator support with a sawzall and un-bolted the two brackets on the torsion bar so that it dropped down out of the way. Then I was able to hook my cherry picker so that the engine was tilted way to the front, and I was able to just barely slip it in( Ihad to remove the rear valve cover to get it to fit in). Once the pan drops behind the crossmember there was plenty of room to work.
I learned that I am going to have to move the engine back about in order to gain radiator clearance, there appears to be about 4" of clearance at the rear of the engine with the tranny in the stock location:
and so upon further inspection of the transmission cross member I saw that it is reversible which should move everything back 3-4". It also appears that the stock cummins motor mounts will probably work best in this install so that should save me some time on making new motor mounts. I think that's about all for tonight... there are more pics located at: http://s761.photobucket.com/albums/xx256/plcnut/99 express 3500 Cummins conversion/ Will keep you updated as time permits...
 

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Discussion Starter #7
Hey guys, sorry I haven't updated lately. I actually managed to get the cross member reversed and the engine moved back about a month ago. But since then my job has kept me tied up so I won't have time to work on it again until at least late November or December. I will keep you updated when I get time to get back on it.
 

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Welcome to the build thread for my second cummins conversion. Following is a basic outline for this new build:

The plan:
Mount the 93 cummins to the 4L80E with a straight cummmins to gm adapter, build a spacer to bolt between the chrysler flexplate and a gm flexplate to keep the torque converter in the stock position, fab my own engine mounts, build either a microcontroller (parrallax Basic Stamp), or a PLC (programmable Logic Controller), to monitor throttle position, rpm's, and boost, to output fake signals to the original gm pcm to control the tranny, as well as keep all the stock gauges work.
I'm curious about the micro-controllers and logic controllers. Have you used these before?
Have you had much success with them?
 

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Discussion Starter #9
I use plc's at work on a daily basis, I do all of the control system design and programming in our facility. The micro-controllers are new to me, I bought a starter kit with a basic stamp to play with, but I have not had any time to so much as open the package... I have a good friend of mine who is very good with the micro-controllers that can give me a hand if I go that route. Do you have experience with either?
 

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I don't have experience with either, but it seems like it would be a practical skill to have for the swap. I'm interested to see how the electronics work for you.

I'm doing a similar swap, but with an Isuzu 4BD1T, and I'll probably keep the 4spd auto already mounted to the diesel.

Good Luck with your build.
 

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Discussion Starter #11
Well, a mere 8 months later I'm finally back on my project! I reworked my cross member by cutting the transmission mounting slot longer so that I could make my motor mounts fit better (I've got pics to put up later). I also had to do a body lift to make things fit right. So I ended up jacking up the body and putting some short pieces of 2x4's that I had in for shims, so I currently have 1 1/2" of lift and that made a world of difference. When I get everything sitting like I want it I will order a body lift kit that is the actual height that I end up needing. I also got my motor mounts fabbed up, they turned out very well and very simple. I pulled the engine back out last-night and then today I was able to get the rear main seal installed, the flywheel installed, the pushrod cover gasket replaced, the kdp tabbed and bolts thread-locked(one of the internal bolts was only finger tight), new front main seal, timing bumped forward 1/8", power steering pump reservoir swapped, oil pressure sender swapped and now I have the engine sitting back in the engine bay ready to line up the bellhousing and bolt in the motor mounts in the morning. (I had a busy day) It sure is nice to finally see some progress...
 

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Discussion Starter #12
Yesterday and today brought some more progress, I finally got the cummins in it's final resting place. I had to get some longer bolts for the bell-housing because 2 of the threaded holes in the aluminum adapter plate had the first 1/2" of threads pulled, when I went to buy bolts I couldn't get any grade 8 bolts that had enough threads on them and so I decided to go with socket head cap screws because they have longer threads as well as they are hardened. I used anti-seize on all the threads and I also used some special lock washers that I found at fastenal, They are a 2-piece washer that is made to slip in one direction and grip in the other, they really seemed to work well, we'll see how they do in the long haul. I spent all day today on wiring, I had to open up the entire engine bay loom and remove all of the unneeded wires and re-route all of the remaining wires to their new locations. Overall it went very well, I left all the unneeded wiring connected to the computer so that I can go in and fake the signals on them to make the transmission shift when I get it road ready. I temporaried the fuel system into a spare fuel jug so that I could fire up the engine and hear it run, but after just a little bit of cranking my starter died :( . I took it apart to see how bad the damage was and was surprised at how dirty and full of gunk it was. It was a little beyond my ability to repair with the tools I had available, and so I will be heading to the starter shop in the morning... Oh well, I guess I can wait another day to hear it run... I had to order yet another exhaust manifold to try and get my turbo to fit, It will almost fit with the stock manifold if I flip the turbo around and run the exhaust out towards the front of the engine, so I decided that If I was going to have to fabricate an adapter to make it work, why not get a manifold that will put the turbo back a little so that I can route all of my piping a little easier so I bought a manifold for an 04-06, as near as I can tell that should put the turbo just right as far as forward and backrards, then I will have to make an adapter to go between the turbo flanges that will drop the turbo alittle and kick it in closer to the engine block. I also plan on using exhaust wrap on everything after giving all the metal parts a thin coat of never-seize, it is supposed to be good up to 1600 deg. and so I hope that it will help to prevent rust, we will see. I also pulled the exhaust housing off my turbo so that I could re-clock it, I had to beat on it pretty good but I got it off. Tomorrow I hope to get started putting the front end back together so that I can start piecing in the cooling system, but that's another day.
 

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Discussion Starter #13
Been lots of progress since my last post... I got to drive it today and I'm pretty excited to get the project finished. Here are some photos: http://s761.photobucket.com/albums/xx256/plcnut/99 express 3500 Cummins conversion/
I didn't get to take a lot of pics, but I did get a few. I also posted some short descriptions with them, they are mostly out of order, but maybe you can get an Idea of how she went. I still have to re-pipe all of my inter-cooler lines, fab a new intake horn, re-pipe my air cleaner, pipe in my a/c compressor, finish getting all the wiring loomed and tied up, figure out how to get a rpm signal into the pcm for the shifting, install new battery cables and a larger battery, take the radiator back out and get the hole in it repaired,finish fabing my upper radiator mounts and get the transmission filter changed. I think that is about it aside from putting the carpet seats and dog house back on, Oh and get the exhaust done at the muffler shop.
 

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Discussion Starter #17
I got all of the parts for my intake and air cleaner ordered today as well as I got most of my tools picked up out of the van. I also got to take my family for a ride in it, They loved it. Slowly but surely... and we'll see about a video. my phone videos don't turn out too well.
 

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Well, I got all of my intake re-piped and a new intake horn built, it turned out super! I also got all of my a/c lines made, I couldn't get the fittings I needed without ordering them so I bought the fittings that the parts store had in stock and had a friend heli-arc the new barbs to my old fittings, it worked out pretty slick. I then test fit all of the hoses and went and crimped them on. Hopefully this next week I can have the system flushed, vacuumed down, and charged! I also got my triple gouge pod mounted on the pillar with my EGT, boost, and trans temp gauges and it turned out good, I wasn't too sure about the gauges I ordered but so far I like them real well. They are motorized gauges with built in alarms as well as peak storage, so I can always go back and see how much boost i had or how high my egt's got even if I wasn't paying attention to the gauge, so that part is pretty cool. I also reworked my tps to make it adjustable but found that it shifted better with the tps unplugged, so I am running the transmission with the crank trigger only(and I'm not sure that it even needs that). Also I have to get my exhaust done, I have not decided what to do with it yet, I think I will just have straight 3" put on it like my truck has and see how it sounds, and I can add a muffler later if we think it needs it (it's my wife's rig or the muffler wouldn't even be considered). The reason I'm thinking about 3" is because it's the biggest that I can have bent locally and I don't think I can get my money's worth out of an exhaust kit, What do you guys think ? all i'm concerned about is economy in this aspect, is the bigger gonna be that much better for the price? anyways, My wife actually got to take it for a drive yesterday and loved it! Tuesday they are supposed to come and instal a new windshield, and then it will be off for inspection and license, so after a year, it sure is nice to be getting it finished!
 
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