The Story Of A Cummins Suburban (Lots Of Pics)

[Lugnut64052]

Great thread you have going here.

Question:
Do you still recall what evaporator you used? I'm getting ready to restore my air and, while I'd like to use the original POA setup, I don't wanna hassle with finding a working one (tested mine and it doesn't work anymore-- a DOA POA), so I'm going to build a CCOT system, which looks like what you're doing. I've done considerable web surfing and it looks like new manufacture POAs have gone the way of the Dodo bird . . . at least for now.

The '73 and up evap cases are pretty similar looking. Also some 70's cars had similar cases. Wondered if you remembered what you used for an approximate fit.

[mosesburb]

Originally Posted by Lugnut64052

Great thread you have going here.

Question:
Do you still recall what evaporator you used? I'm getting ready to restore my air and, while I'd like to use the original POA setup, I don't wanna hassle with finding a working one (tested mine and it doesn't work anymore-- a DOA POA), so I'm going to build a CCOT system, which looks like what you're doing. I've done considerable web surfing and it looks like new manufacture POAs have gone the way of the Dodo bird . . . at least for now.

The '73 and up evap cases are pretty similar looking. Also some 70's cars had similar cases. Wondered if you remembered what you used for an approximate fit.

A DOA POA. Yup, seen many of them. The only thing that is made these days (that I know of) is a POA eliminator kit. It is kind of a neat deal, but I haven't seen one in several years so I forget what it consisted of.

As far as what evaporator I used--I forgot that also. I do know that you can not use the '73 and up unit because of the "U" shaped low side (outlet). This unit will put the accumulator into either the fenderwell or the hood hinge or spring--I forget which. I tried MANY different ones and what I ended up using was not something that seemed like it should work by application, but in form it worked great. This system has not been charged yet, but I got all of these parts for a buddy of mine to use in his K5 and it works great in his truck. I'll get into my file cabinet and do some digging in the monstrous file titled "Suburban" and see if I can find the invoice and get you a p/n.

[mosesburb]

Originally Posted by Lugnut64052

Great thread you have going here.

Question:
Do you still recall what evaporator you used? I'm getting ready to restore my air and, while I'd like to use the original POA setup, I don't wanna hassle with finding a working one (tested mine and it doesn't work anymore-- a DOA POA), so I'm going to build a CCOT system, which looks like what you're doing. I've done considerable web surfing and it looks like new manufacture POAs have gone the way of the Dodo bird . . . at least for now.

The '73 and up evap cases are pretty similar looking. Also some 70's cars had similar cases. Wondered if you remembered what you used for an approximate fit.

FOUND IT!! Man, that is a big file......

Anyways, 15-6249/3035171. Link to image Application is: '77 Chevelle, Monte, Impala. From what I can tell, it was used for a little over a year, so avaliability might be tough. The only major size difference between this unit and the original unit core-wise is this unit is one "row" shorter. IIRC, I made a thin strip of sheetmetal to fill the space and to mount the weatherstripping to. With my huge condenser and the duct mods under the dash (eliminate one hose going to the center vent for improved airflow) I figured the one tube missing would not be too noticable.

15-1648 Accumulator with the inlet at 6:00 and the outlet at 3:00 (pointing at pass fender) This one works good because the high side hose and low side hose can be run together, uh, "bundled"(??) for a cleaner look to the hoses because the evap inlet on the 15-6249 points at the pass fender also.

(The 15-xxxx numbers are AC Delco numbers)

Hope it helps.

[70rs/ss]

This is my Suburban, have you been stealing my thoughts!? I want to build this exact Burb, so I can have my cake and eat it too!! Diesel for power and MPG and 4X cause I want it and the whole package to replace the $40K 05 Yukon XL I totalled. I think the 67-72 Burb has way more style and class, plus the diesel power and economy, as well as 4X anyways, when you get done building my Burb, I'd like to get the keys back from you!! This is so sweet, one day, one day!

[mosesburb]

Originally Posted by 70rs/ss

This is my Suburban, have you been stealing my thoughts!? I want to build this exact Burb, so I can have my cake and eat it too!! Diesel for power and MPG and 4X cause I want it and the whole package to replace the $40K 05 Yukon XL I totalled. I think the 67-72 Burb has way more style and class, plus the diesel power and economy, as well as 4X anyways, when you get done building my Burb, I'd like to get the keys back from you!! This is so sweet, one day, one day!

Ha, ha, ha!! Dood, for $40K, you can come and get it right now!!

Thanks!!

[Lugnut64052]

The only thing that is made these days (that I know of) is a POA eliminator kit. It is kind of a neat deal, but I haven't seen one in several years so I forget what it consisted of.

That's right. Basically, all they are is an orifice with a low side switch and the orifice is all that's "controlling" evap pressure. Sometimes they cool okay, sometimes they don't, mainly due to varying environmental conditions (ambient temperature, etc).

I do know that you can not use the '73 and up unit because of the "U" shaped low side (outlet). This unit will put the accumulator into either the fenderwell or the hood hinge or spring--I forget which.

Hmm . .yeah. That'd be right.

I'll get into my file cabinet and do some digging in the monstrous file titled "Suburban" and see if I can find the invoice and get you a p/n.

Don't want to derail your excellent build thread, but it'd be muchly appreciated. CCOT systems were a step down from POAs. Fewer parts, cheaper, and they cool fairly well. A healthy POA system would freeze meat in a Caddy Fleetwood, but the reality of increasingly scarce parts forces me to go CCOT.

. . . and just as I was about to smack the "Submit" button, your part number came through.

Thanks very much!!

[Arad68]

Very Cool Build!!!, Subscribed!!!

[scapegoat]

What did you do for motor mounts?

I was thinking of putting a cummins in my 69 setpside... but seeing that oil pan... i'm not to sure I'll have the ground clearance now...

[mosesburb]

I used mounts from a 1st Gen Dodge. The mounts are simple, one stud on the top and one stud on the bottom. I would not encourage a Cummins swap due to the work, time and fabrication involved, but if I can do it, it is obviously not impossible. The oil pan is not too terribly deep. The front portion of the pan is only about one inch below the bottom of the block and it drops into a sump that is comparable to a SBC toward the back. If your stepside is a 2wd, the swap would be much easier as you can use the crossmember you already have.

[scapegoat]

Originally Posted by mosesburb

I used mounts from a 1st Gen Dodge. The mounts are simple, one stud on the top and one stud on the bottom. I would not encourage a Cummins swap due to the work, time and fabrication involved, but if I can do it, it is obviously not impossible. The oil pan is not too terribly deep. The front portion of the pan is only about one inch below the bottom of the block and it drops into a sump that is comparable to a SBC toward the back. If your stepside is a 2wd, the swap would be much easier as you can use the crossmember you already have.

yes, my stepside is 2wd... I haven't done a crap load of work on vehicles... pretty much cutting my teeth on this chevy. Other than logic and common sense on my side...

I'd just love to hear a turbo diesel under the hood. How well do the mounts line up, is there any fab work required?

Awesome project, can't wait to see some videos of it running

[mosesburb]

Originally Posted by scapegoat

I'd just love to hear a turbo diesel under the hood. How well do the mounts line up, is there any fab work required?

With a 6BT the mounts will probably not line up with anything. I can't say how much fab work would be involved ona 2x, but if it is anything like a 4x my answer would be yes, much. If you have to have the sound of a turbo diesel check out a 4BT. Much, MUCH easier to adapt (practically a bolt in compared to a 6BT).

Originally Posted by scapegoat

Awesome project, can't wait to see some videos of it running

Yeah, me too!!

[earl87gta]

I would think a 2WD would be harder in a 4wd you can make a new cross member or buy one premade for the convertion if you dont want to do it your self. But a 2wd you cant just replace the cross meber do to it being part of the front suspention so you have no choice but to modify it. There is a guy on the diesel boards and he hangs out on pirate4x4 alot too that sells convertion kits for the 4 and 6bt convertion. Ill try and get his contact info and post it here if thats ok so that every one folowing a long will have an option to buy the parts need. He mayeven have done a 2wd to help out with 2wd questoins as well.

[70rs/ss]

OK I own a 24 valve cummins in my 07 Dodge, but the 6bt and 4bt thing throws me, I know what a 12 valve is so what is the 4-6bt??? I am interested, as buying a install type kit would be worth every penny for me cause my time is worth more than $$$ in most cases.

[mosesburb]

Originally Posted by 70rs/ss

OK I own a 24 valve cummins in my 07 Dodge, but the 6bt and 4bt thing throws me, I know what a 12 valve is so what is the 4-6bt??? I am interested, as buying a install type kit would be worth every penny for me cause my time is worth more than $$$ in most cases.

6BT is:

6: Number of cylinders

B: Cummins engine series

T: Turbo

And technically, I am dealing with a 6BTA in my conversion

A: Aftercooled (Intercooled)

So to make a long answer longer, a 4BT is a four cylinder version of the 6BT. There are several sources for them. They do not live a long happy extended life when the screws are turned, but they do make respectable horse power while making gobs of torque (keeping in mind they are 3.9L). With the correct gearing, a fun-to-drive vehicle could be had while making some extremely impressive mileage. If I had it to do over, I'm pretty sure I would have gone with a 4BT. So much simpler. There are factory mounts to mate up with GM truck frames, adpaters to mate up with GM bell housings and being two cylinders shorter, much easier to adapt.

4btswaps.com has some good info on them.

[mosesburb]

I got a little more done here this weekend. I have been working on the intercooler tubes off and on for awhile and finally got the fitted. They worked out pretty good as I was able to re-route and re-engineer them to fit where they need to be. I cut some out here to bring this up or over or down and I used the chunk I cut out to lengthen this piece or drop that part down etc. When the sparks settled I ended up with about 3/4" of tube left over.

Passenger side tube:



A different angle:



The way the Banks kit was set up, it used a hose that ran from the intake plenum, ran across the top of the motor, across the exhaust manifold, past the turbo to the wastegate actuator (the thing with the green cap on the end of the hose nipple). I did not really care for the aesthetics of that. The pressure is the same after the turbo and before the intake manifold anywhere in the system, so I decided to make the plumbing a bit cleaner. I installed the passenger side tube and reached around to the back and found a spot that could not be seen from the front of the vehicle. I pulled the tube back out and put a dot on it. I then bored a .187 hole in the tube and took a hose nipple I made out of a piece of .187 brake line that I put a bubble flare on the end of and silver soldered it into the intercooler tube. Now, a hose can be run off of that nipple around the back of the I/C tube and loop up and around to the wastegate actuator. Instead of the hose hanging out in front of GOD and everybody, it will just kind of show up from out of nowhere and loop around to its final destination. About one foot of hose versus about four feet.

Like this:



The driver's side was quite the pain in my hinder. I think every straight section of the pipe had to be modified. After all the work that went into it I think it looks pretty good. In the bottom of the pic the infernal power steering lines can be seen. The chunk of bulk hose running kind of parallel to the I/C tube is power steering fluid return to the pump from the cooler that needs final routing and to be trimmed to length.



I built my hydroboost and installed it awhile back, but there was no photographic proof of it. I was going to use a H/B off of a late 80's V3500, but the mounting plate was so gangly I did not like how it looked and was not enthused about the amount of work needed to make it fit. I had another H/B off of a '99 C3500. This is the way to go. It has an extremely simple mounting plate that lends itself well to modification. I inverted the mounting plate and bored two holes in it and that was it--done. I had to enlarge the hole in the firewall a few thousandths to get the nut that holds the H/B unit to the plate to fit through the hole and I lengthened the input rod a bit. I used some fluid lines for a mid 90's C3500HD with a 5.7L. They were NOT a bolt on deal, but they required the least amount of modification to fit (the least amount, but still a lot). I liked them a lot because they come off the H/B unit on the engine side of the unit instead of the fender side like the V Series hoses. This gave me room for my clutch master cylinder which is also visible in the pic. Obviously it is in, but I do not have a couple key pictures to illustrate the work done and it would take too much to try to explain what I did, so I am going to hold off describing that whole deal until I get a few pics of a couple parts.

[scapegoat]

from my 30 seconds online looking into the 4bt... i've read they don't last very long at hp levels around 250... so that nicks that idea.

there are always big blocks for me

Oh well, i'll still be keeping an eye on this build

[earl87gta]

Originally when people did a 6bt swap they used the 4bt adaptor plates a lot of your fredolay and UPS trucks used a 4bt with a th400 trans mounted behind it. The reason you don’t see a lot of guys doing this with the 6bt is that it turns the engine I think 10 deg to the side so the engine is not setting straight up and down witch made for clearance trouble with the 6bt in most trucks. This isn’t a problem if you use a dodge trans. you can use a 4bt cross meber too if you can score one to use with a 6bt.

[Critter]

Words cannot describe the coolness of this build!!!

[Long Roof]

I am anxious to see the smoke roll out of the exhaust pipe. Keep it going.

[Hoot71Burb]

MosesBurb - I just bought a 71 Suburban and was interested in putting a Duramax under the hood. However, due to the difficulty of the endeavor I decided against it.

Your details of your build make me change my mind. Maybe an endeavor with a Cummins is in order????

By the way, I'm up in Prescott Valley.

[mosesburb]

Originally Posted by Hoot71Burb

Your details of your build make me change my mind.

Hey, hey, hey now, don't be blaming me for this.

Originally Posted by Hoot71Burb

Maybe an endeavor with a Cummins is in order????

I have not done too much research on the DMax, but I have a feeling that the DMax might be a physically easier swap because it is shorter in length and height, but a much larger ordeal in electrical, wheras the Cummins would be a more difficult physical swap but much easier in the electrical department.

Originally Posted by Hoot71Burb

By the way, I'm up in Prescott Valley.

Welcome to the board.

[FRENCHBLUE72]

Wow nice build thread..

[mosesburb]

Well, I snuck out for a couple hours this weekend and got a couple things done. Actually, I got nothing done. I bolted a few parts on and stared at them, but that is progress, right??

Anyways, from a previous post this pic might look familiar:



The situation is, even with removing the flared portion of the frame rail, the water inlet was still obstructed by the frame rail. Another issue present with this setup was A/C compressor clearance. Most people who put a Cummins in a GM frame need to notch the upper portion of the frame rail for compressor clearance. I have the motor set so low that I was going to have to notch the LOWER portion of the rail. I did not think that would be so cool having the compressor free-balling it down below the frame and coupled with the water inlet fitting issue I decided something else was needed. This is what I ended up with:





I'm not sure of an application. It *might* be off of a Kenworth chassis, but I do not know for sure. It is brand new, but got moist during an event where water was falling out of the sky and it developed the reddish coating on it--I think it might be called rust and the cause of it might be called rain--not sure though ;-). Anyways, it has a separate fitting that mounts onto it for the water inlet. This is great except a fitting is not made that will work for my application--no surprise there. I have my flange made and it is mounted on the housing. I am going to make the nipple for it out of a piece of heavy wall, mandrel bent exhaust tubing to clear the frame rail. The top of the housing will mount a bracket for the bottom of the alternator. This unit mounts the A/C compressor directly above the water inlet fitting up and away from any frame rail interference. Of course with this I needed yet ANOTHER different water outlet fitting (thermostat housing)--I think this is number four. The machined flange on the water outlet fitting will not be used. It looks just like this:



Part of the reason for needing another different water outlet was because a bracket for the top of the alternator was needed. It looks like this:



It is going to get a slight modification later on for reasons relating to lack of space for another part, but that is s story for another day. Now, with all of this, I get to use a different alternator. I decided to go with a nice hefty medium duty truck unit. Dodge alternator on right, MD truck is on left--slight size difference:



Here it is mocked up:



I just went over to Russ's (BadDog) house this afternoon and picked up a part he machined for the lower mount. Cummins makes what I need, but I ordered one several months ago and still have not received it. I guess they are still doing a survey to see if there is iron ore where they want to start mining. Then they will have to start the mining operation, process the ore, get it to a steel mill to be made into a part that I ordered. That being the case, I decided I will make one myself. I also dropped off some raw materials while I was there for him to machine into something REALLY cool that is going to help me deal with another issue that pooped up, but, once again, that is a story for another day.

I was a bit nervous about clearance for an accumulator to fit near the intercooler tube, so I dug out one that I had here and did a test fit:



By the looks of it, I am guessing my eyes were in calibration when I laid it out because it looks like it will fit good. The pic does not illustrate it too well, but there is a decent amount of clearance all the way around it.

[70rs/ss]

Reading all of this again, I think this is why I initially started planning to do a body swap onto a Dodge frame/running gear. I think that might be the ticket still. if a body lift is needed then that'd be OK too since those are off the shelf parts. You are doing a bang up job, I just wondered if my idea made sense to anyone else but me?? I am on the trail of a decent burb but a 2wd so a good 4X Dodge truck for a frame/drivetrain donor and I am ready to go!

[mosesburb]

It has been done before. I never saw it in person, but I saw a few non-descriptive pics of it. The guy stated that it was easier to do that way--I have no idea how it could be seeing as how most everything regarding clearance issues will still need to be dealt with. The frame rails are set wider so the compressor is not an issue, but all the fun of fitting an intercooler still lies ahead and with the wider rails, fabbing body mounts may be a hoot. Definitley go with a 1st gen Dodge if you go this route. I think engine height is going to be a substantial issue because the motors sat pretty high in those frames. Might be worth a look. You know what is involved doing it the way that I am so you will have something to judge it against labor-wise.