cummins 6bt in a cucv

[1984CUCV]

I have a 1984 m1008a1 with 14k original miles on in and want to put a cummin 6bt or a 4bta in it. Does anyone have a place to recommend where I could purchase a 6bt for my conversion? any help would be greatly appreciated. Thanks!!

 

[mangus580]

I would highly suggest the 4bt instead of the 6. I don't think it will take much work 'converting' things for the 4bt.


Just my

 

[gimpyrobb]

Yeah, might want to look into weights of the motors first. I'd say 4bta would be your best option. Have you looked over at coloradok5?

 

[WillWagner]

A 6 will work. You will need to run an electric fan though. No room for the hub mounted fan when it's stuffed in it. Keep this in mind. You will lose road speed. the B is 2500 rpm rated and...i'm not too familliar with the engine in the CUCV series, but I think they turn around 3200-3600? Figure 3 to 4 mph per 100 RPM. Even if the stocker turns 3000, that is still a loss of around 12 MPH..at rated RPM. Your mileage will suffer if you do lots of highway driving. All of the trucks i've seen converted had an overdrive of some sort on them. If you do it, you will need a trans adaptor from a 4B in a GM 1 1/2 ton step van. It tilts the engine about 8 degrees to the exhaust side, so the fuel pump and PS/vacuum pump clear the frame. The 6 is tight, but it does fit rather nicely. I saw a 4 in a Jeep Wrangler the other day. Looked good, but he said he lost about 20 MPH .

 

[1984CUCV]

I am not really concerned with 'top' speed as I am running 36 inch tires and will use the stock 400 trans. more concerned about making sure it has enough hp to turn my tires and pull my horse trailer. that is why i am leaning toward the 6bt instead of the 4bt.

 

[beaubeau]

Hey 1984cucv, talk to my son,{NHDIESEL}. He just instaled a 4bt in a 2000 Durango and it came out well. We used it to pull 2 M105 trls from Loring AFB in Me. last Friday. It ran well and handled the trls OK. I guess he dubs with the fuel pump to get a little more response out of it. You can find many 4bts afrom Frito Lays old trucks.I have a couple 5.9 here in a couple 1997 Dodge 2500 that I am using for different projects. Good luck finding what U want. Phil

 

[area52]

4bt swap

I would also recommend the 4bt, it weighs less, shorter also.

Unless you plan on towing very big loads, the 4bt should do fine. You can turn up the fuel and make other adjustments to get the power and torque you need.

Here is a website that might help you:

http://www.4btswaps.com/forum/index.php

 

[1984CUCV]

hey beaubeau, does your son have a phone number i could reach him at to discuss his conversion? You mention Frito Lay trucks have the 4bt - can you recommend a place whre i may purchase a good used one. I know Ralphs truck world in Portsmouth NH has used engines but they do not have any 4bts. Besides I just moved to Florida from Maine and would like to find a place a litlle closer to home if you will. Thanks to all for your help!!!

 

[CGarbee]

www.dovebid.com handles the sale of the Frito Lay (and other) route vans with the 4BT and such... Sales are all over the country, and they give you the contact info for the on-site managers so you can talk to the guys who have been wrenching on the trucks before you bid. The transportation exchange sales come up every four to six weeks...

Good luck.

 

[AJMBLAZER]

A TH400, unless well built, is on the ragged edge of survival with the torque a 6BT puts out.

 

[tsmall07]

A TH400, unless well built, is on the ragged edge of survival with the torque a 6BT puts out.

What would you suggest? If I were doing it, I'd pick a manual. Are all the holes and such pre-drilled and tapped for the various pieces required to make the truck a manual?

 

[CCATLETT1984]

for putting in that engine, you'd want to go with a hydro clutch setup, i dont think there would be room for the linkage of the stock setup.
but the stampings are all there, and iirc the holes are as well.

 

[nhdiesel]

Hi, I'm BeauBeau's son, with the 4bt powered Durango. Unless you wanted to tow crazy heavy trailers, a 4bt would be a great fit, and extremely economical. On that trip up to Maine, we got around 27mpg without trailers. I have it hooked to a Dodge NV4500 5-speed. The majority of the Frito trucks come with GM adapter plates so you can bolt up any GM transmission. The most important thing to watch for is gearing. If you want to use it around town and pull trailers, go with something like 3.73 gears, or 4.11 if you really want tall tires. 3.73 is what I would advise. If you want to cruise the highway and still have plenty of power around town, 3.54 is great...thats whats in my Durango with aprox. 31" tires (245/75/16) and it cruises at 70 nicely. I've had it to 99 just to see what it would do, and it got there fine, but anything over low 70s really starts using more fuel.

For 100% economy, 3.08 would be great, even in a fullsize 4x4. Even with two M105 trailers behind it, taking off in 2nd gear was easy. The only issue we had was high exhaust temps on hills, we had to watch the gauges. Thats only because my motor was originally a 4bta (aftercooled), but to use the Dodge grid heater for our very cold winter mornings, I had to eliminate the aftercooler, and I don't have an intercooler installed yet. Before I do any more real towing I'll get an intercooler in place, then it will pull like a freight train. 400+ lbs. of torque is very easy to get with these engines. In comparison, my 1996 Ram Cummins was only rated at 380 lbs. of torque from the factory.

With the various adapters available, you can bolt a 4bt (or 6b) up to a Ford, GM, or Dodge transmission.

Jim

 

[1984CUCV]

Where did you get your 4bt. have seen a few for sale but they are either low hp (like100) or they are way expensive (4k+). I have plent of room for an aftercooler especially if I use the 4bt instead of the 6bt.

 

[mitchellracing]

i have done three ford 6b cummins swaps they do fit in a ford if you move the firewall back 4 inches hyro clutch is the easiest way. you dont want to put an auto behind it as even a stock 4spd manual tranny and clutch cant take the torque two of the trucks had 4spds one a 5 spd cummins make a kit to put in chevys and ford its around 1500 youll want it it has all the parts and peices youll never imagine youll need a 6b cummins of any count will prolly run ya atleast 4grand if ya go the manual route youll want the big clutch been there done that its 600 the 6b weighs 2500lbs so youll have to have something big enough to handle it the 6b is 6inches longer than any v motor that would be in a ford or chevy if you have a 4spd tranny youd want at least a 3.52 rear gear or a 5spd a 3.73 the one truck had a toold bed and weighed 12000lbs and got 14 mpg the one witha regualr p/u bed gets 18 or 19 but it has a 5spd in a ford i know you cant use the electric od auto tranny because there r none of the electic hookups for it i dont think a chevy od tranny would work either the best bet is to get an entire dodge engine tranny and transfercase in all honesty if ya want a cummins powered truck buy a dodge this comin from someone has done 3 conversions and put 300000 plus miles on convert trucks unless ya have deep pockets a spart motor and tranny layin around a got weldewr and fabricatin ability and alot of spare time ITS NOT WORTH IT but heres some pics of one and if ya have any questions ill try to help ya

 

[area52]

Just a side note: the Frito Lay trucks with the autos came with the TH475 which is a heavier duty version of the TH400.

there is also a webcast auction on Dovebid in Pomona CA coming up on Feb 7th that has a lot of 4bt trucks.

 

[nhdiesel]

I disagree about many of the above statements. The 6b doesn't weigh 2500 lbs...it weighs around 1100. The 4bt weighs around 750, or about the same as a big block gas engine. As for cost, I compared my Cummins swap to replacing the bad 360 gas engine with another 360. I already tried the junk yard route, and the motor only lasted about a month after the warranty was up...I had around $1500 into a junkyard replacement, which lasted 4 months (thats a $650 engine, all new gaskets, seals, timing set, new exhaust manifolds to replace the rusted ones, and more). A new engine would have cost me at least $3000, and thats with my labor installing it.

I have around $4000 cash into my 4bt swap, which includes a $2000 Frito van, $650 low mileage NV4500, $500 clutch and flywheel from Napa, Dodge bellhousing, Dodge flywheel housing, clutch hydraulic parts, exhaust, and lots of misc. items. I still have an aluminum Frito van in very good condition, which I could get $1500 out of just for the aluminum; or toss in a couple hundred dollar 350 and sell it. So in the end I will have around $2500 into it.

The labor of installing a small Cummins into a straight axle truck is very little...fab up the motor mounts and bolt it all together. I had TONS more work, because I have IFS in my Durango, so I had to fab a custom oil pan to clear it; and my front differential actually bolts to the engine (dumb Dodge design), which I had to fabricate complex brackets for. I also put a manual trans into a vehicle that never came with one, and fit a 3/4 ton transmission into a vehicle that never came with a trans that size. Even with all that, the actual work took about 5 three day weekends. There were a couple weekends we took off while waiting for parts, but the actual work was about 15 days. At least 3 of those weekends were spent just making the oil pan and diff brackets.

As for the firewall statements, thats just not true. Check out www.fordcummins.com for kits to install a Cummins 6b into just about any body style Ford, with NO sheet metal modification. I even know of a guy who put one in a Dakota without moving the firewall! I have tons of room with the 4bt, I can see how a 6b would fit. For clutches, there are many out there to handle a 6b. You can get a stock replacement for a couple hundred bucks that will handle a stock 6b. No, I wouldn't trust a 4 speed behind a 6b, at least not if you plan to work it hard.

For more info about the 4bt swap, go to www.4btswaps.com Adapters won't cost all that much...I sold my Chevy adapters that came with my Frito truck on ebay for $300. That included the flywheel housing, flex plate, torque converter, and flexplate crankshaft adapter. Everything you would need to hook it up to a GM auto trans, and all you would need extra would be a flywheel for a GM manual trans. I would say you could bolt a 4bt to a GM trans for under $500, auto or manual.

Pics of my Durango swap: http://s226.photobucket.com/albums/dd315/nhdiesel/Cummins Durango/

Jim

 

[mitchellracing]

i dont doubt a 4b would fit in with no firewall work but in a ford and a 6b from the top of the back valve cove to the tope of the tranny has to be moved 4 inches and ive seen on ford cummins were they said that and had a picture of one cut out and refabed as for a chevy ive seen a guy did one and i dont know how he shoe horned it in there i guess they fit but as for weight our forklift with 2 600 lb tractor weights and 300 lbs of lead back there plus whatever it weighs will barely stay on the ground when pickin up a 6b we have 4 12v and 3 24v 6bs in service everyday they are great engine but it isnt just a wam bam your done job a 4b tops at around 110 hp with turbo and aftercooler probably not enough hp i ya ever do any heavy pulling just a diference of opinion but be sure ya check out ever possible problem and situation and all your expenses before ya start

 

[nhdiesel]

More wrong info. I hate picking apart posts, but someone wants real facts, and I want them to be informed. A stock 4bt without aftercooler is about 110hp. A 4bta is 120hp (which mine is, just check the CPL pates to see what they are rated for), and 130hp versions are available. Yes, low HP...but these are diesels, and HP numbers are low...but torque is high. My 6b was only 160 hp when stock! With minor pump adjustments the stock 300 lbs. of torque can be increased to 400, 450, or even more torque. Power? My little 120 hp motor, before adjusting the pump, would spin the tires on bare pavement in 4x4. In 4x2 its downright fun. Slight pump adjustment let us tow 5500 lbs. of trailers 350 miles behind a 4000+ lb. Durango without breaking a sweat.

Your weight calculations sounds very precise. I guess the stated Cummins specifications must be off by 1400 lbs. then. If you want to see where a 6b will fit, go to youtube and search for Cummins Monte Carlo. There is an early 70's Monte with a 6bt in it. I don't know how they did it, but its quite cool. Go to 4btswaps and check out all of the guys who have swapped 6bt's into Chevys, Fords, and anything else...there is a whole section on that site just for 6bt swaps, since they are so similar to the 4bt.

1984cucv, I bought my van from www.dovebid.com Keep watch there, vans come up about once a month. One sold in my state recently for $900 in running condition. Too bad, because I had already bought mine in N.J. and towed it home. Keep in mind to subtract at least $1000 from the price of the bread truck for the scrap value of the aluminum. Grab a sawzall and hack it up and you will get a bunch for the aluminum body. If its in good shape, I'm sure you could sell it locally to someone who would want to put an engine in it. Some of the vans come with Ford adapters and transmissions, and there are even some manual trans trucks around. I happened to get one with the TH475. That wouldn't be bad for you, just swap tailhousings and tailshafts with your trans (if you have a TH400) and use the bread truck trans.

Jim

 

[AJMBLAZER]

What he said.


There's several guys running around on www.ColoradoK5.com with 6BT powered 73-87 GM's and the gist is it isn't terrible to do.


In regards to the earlier question to me personally if I was taking the time, cash, and effort (or just cash and someone else's time and effort) to swap a completely different diesel into Big Ugly I'd have a NV4500 put in. I love rowing gears and I miss OD.
That said a well built TH400 could hold up to a mild to moderate Cummins pretty easily. However a stock TH400 was never put behind anything with near the low down torque of a Cummins.