4BT Conversions

[JimmieD]

As I've mentioned before I'm in the middle of doing a Cummins 4BT conversion into my Town Wagon. It's a little more espensive of a proposition than I had thought at first.

I want to go all Dodge parts so that includes a Dodge bellhousing adapter, Dodge bellhousing, Dodge NV4500 trans, Cummins Hydraulic clutch slave with a hydraulic master and assorted linkage etc. plus tranny output yoke, custom built driveshaft, and a rear end that can handle some torque. Fuel tank and system requires either some mods or replacement, plus all new exhaust to handle diesel's output, 3" minimum. You're looking at somewhere in the neighborhood of $6000 to $8000 depending on how cheap you can find a donor truck for the engine.

I want to use mine for towing so there's an additional problem: braking! The diesel offers no compression braking at all, and our old trucks weren't blessed with the most efficient brakes on the planet. So an upgrade to front discs is a $erious consideration. In addition, for towing you need more, like a compression brake [Jake or Pac-brake] or an exhaust brake [US Gear D-Celerator]. Those aren't free, at a minimum of about $1,000 - $1500. Jake or Pac-brake require that you change to heavy duty valve springs to get the compression power needed, and that then cause parastic drag on the engine's output plus accelerated wear on the cam etc. These various types of brakes give you the level of braking necessary for long downgrades while hauling a load.

Stock 4Bt is 105 hp and mayybe 350 torque, so many will want more power for towing or even general use. The hp parts get right up there in the pricey range real fast! Pretty easy to dump $3,000+ in power adders.

What's my point? Just a caution to those planning such a swap to look at the unexpected costs before you undertake the conversion. You can save some by using the trans that comes with a breadvan, if you think you can trust a GM Turbo 400 for all your shifting needs. Some few have GM SM465 manual, but for full benefit of the diesel's capabilities and its low rpm power curve you really do want a 5 speed o'drive tranny.

This is NOT a low budget swap, believe me!

JimmieD

[Charles Talbert]

Indeed

It ain't low budget, however you'll love it in the end. Fuel economy is SWEET as compared to a gas hog. Expected long low maintenace life is also great with the new Cummins we install, (could vary using a take-out engine). Just depends on the anticipated use, the individuals available cash flow among other variables as to the investment being justifiable. Every persons situation is different.

[JimmieD]

Well said, Charles, and I agree completely. I wouldn't be doing it if I didn't think it was worth a LOT of work and the considerable expense. It's quite an undertaking, but for me, been there and done that before a few times. I can't wait to hear it fire up and roll it out on the road. As you know, my point relates to: "Does any man go to war without first judging the cost?" My intention is to warn folks that this ain't no weekender, and bring the Visa card! If I had a lot more brains and a bit more money I'd just haul it down to your shop for sure ha haha!

JimmieD

[p14175]

I just saw this post and had to pipe in.

We are in the midst of repowering a 1954 Willys 4x4 Station Wagon with a Cummins 4BT. My '66 W200 is next in the queue, though I am thinking with that one I'll just swap move the body and bed onto a newer pickup truck chassis. The Willys is our second 4BT conversion. Our first was a 1980 IH Scout II.

Consider replacing the braking system with a hydroboost. The Cummins power steering gear box produces enough pressure and volume to run one successfully. If your engine came from a Frito-Lay truck, it should allready have the hoses for using a hyroboost. This might require retrofitting a set of hanging pedals.

The Cummins 4BT is a smaller version of the 6BT used in the Dodge trucks. Many parts are interchangeable. Depending on what part of the country you live in and what you are planning on towing, you might look at retrofitting the mechanical cooling fan. There are two variations on the Dodge 6BT mechanical fan setup. Both will work on the 4BT. Which one you use will probably be dependent on the amount of room you have in the engine compartment. On the Willys, I can use the 1989-1993 set up because the wagon has a deep engine compartment. The 1994+ mechanical fan setup lowers the fan and moves it to the left a little bit.

The other item you need to take seriously is getting an aftercooler to fit. I got one for the Willys from an Isuzu NPR. Isuzu makes similar sized inline-4 turbo diesels and I was able to find an aftercooler-radiator mated pair cutout from one of those trucks that fits perfectly in the Willy's engine compartment. I purchased the set from FMI Truck Sales & Service in Portland, Oregon. www.fmitrucks.com. I am not sure if the numbers on the radiator and aftercooler are part numbers, but if you are interested, just post a note. I'll dig them out.

I don't know how Town Wagon fuel tanks are mounted. I am using a 27-gallon diesel Blazer tank. Coleman's Army Surplus sells brand new ones for $25. You can still get tank hanging straps and sending units for these tanks from a variety of aftermarket Chevy truck parts shops.

One more issue that most people don't take into consideration is the fact that the Cummins B-series engines have the exhaust on the right side of the engine. If your front differential is on the right side, you can have interference issues between the front drive shaft, transfer case, and exhaust routing. We learned our lesson on this from the Scout so the Willys got a left drop front differential to make routing the exhaust a lot easier. Yes, it is blasphemous, but it works better. The W200 will get the same treatment.

Yep! you're right. A repower costs around $6000-$8000. I think I have passed that mark with the Willys, but the old wagon needed a lot of extra work to do it right.

[JimmieD]

Wow, lots of good info. Let's see, where to start?

This particular P-30 stepvan doesn't have power steering but has hydroboost brakes installed. It uses a Cummins P/S pump but it's a strange affair, mounted over brake pedal and then angling to the passenger side. It's 24" from pedal mount to end of hydro unit, and that's a lot of real estate on my firewall! May even cause clearance problems installing engine. Trying to figure out how to use part of it and still have room for my hydraulic clutch. That was part of the reason for using an exhaust brake, especially when towing. Trailer also has electric brakes so it should be okay. I do have hanging pedals already so that helps.

Don't know regarding fan. I have the electric puller from the stepvan, plus I've got a dual pusher electric set from a Dodge Intrepid. I have a heavy core in my radiator and it was enough to cool a 360 pulling a heavy trailer and truck full of equipment in southwestern deserts in the peak of summer with nowhere near an overheating issue. I've been advised that's enough, so hoping....

The aftercooler is on the wishy list! I'll have to wait because of budget and may be using water/meth injection instead to help cool the mix. I'm thinking the water/meth injection might give more cooling and bang for the buck than an aftercooler, and still be a performance asset if I can install the cooler. Don't know if I have room for aftercooler as I've never measured one, but thinking that whole install would cost more than the injection kit.

I was fortunate that the stepvan 25 gallon fuel tank will fit right in between the rear frame rails where my stock tank is. This is a Town Wagon similar to a Willy's wagon. My only worry is getting the right fuel gauge to match the ohm's rating of the Chevy sender, but I'm planning on installing all new gauges.

I haven't test fit the engine yet and have some concerns about exhaust clearance at firewall. May be okay, or may be modifying the sheetmetal. Another project is to use the stock 318 Poly bellhousing hydraulic master and slave on the Cummins clutch. A bracket is necessary, and some kind of DIY clutch actuator rod. Probably the least of my worries. This is the strangest swap I've ever done as I have little knowledge of diesels or 4BT's and can't even recognize what some of the parts are for?!? :~0

Lots to learn and lots to do. Not for the faint of heart or Vice Grips and a big hammer crowd. Thanks for tips, all is very much appreciated!

JimmieD

[Bill in MI]

Keep it coming fellas, I'm writing as fast as I can................. Actually, I have bought my engine and I'm collecting parts. If I run across anything I can share - I will. Thanks.
Bill

[p14175]

Here are the websites where our Scout and Willys diesel repower pictures are kept. We are a little behind right now on the wagon project. We have 4 other 4x4s that need a little TLC every once in awhile.

http://community.webshots.com/user/p14175
http://community.webshots.com/user/glock45x

In both the Scout and the Willys we had to modify the passenger side firewall to give the downpipe room.

The 4BT in the Scout is sitting vertical and the transmission (Dodge NV4500) is tilted. This setup works fine. The transmission mount had to be tilted to match, but that was easier that trying to get the transmission vertical and tilt the engine.

The 4BT in the Willys is mated to a 518 auto transmission from a 1993 Dodge Cummins. The adapter plate allows the transmission to be mounted vertically with the engine. We aren't done with this part of the project yet and still need to work out the transmission linkage and other fun stuff.

One handy piece of advice: Buy a parts book for your engine. These can be had by CPL and Engine serial number or you can get a generic one directly from Cummins. Also get a parts book for the 6BT since some parts are interchangeable. The Cummins dealers don't work the same way as auto parts stores. They deal with part numbers, not the year and model of the vehicle. If you have a Cummins dealer nearby you be in even better shape. Don't buy parts from a Dodge stealership unless you absolutely have to. Their markup is incredible.

http://powerstore.cummins.com/service.html


Linda

[JimmieD]

A picture is worth...PRICELESS!!! Wow, those are just great! I doubt that I looked at all of the images but what I saw answers dozens of questions.

After your last post I went and looked at the hydroboost unit on the P-30 again and came to the same conclusion you did! It's do-able. I will be using a Borgeson steering shaft as you did, and many of the other items you show are a BIG HELP. Thanks! Now back to the pictures..... :~ )

JimmieD

[CGarbee]

[One handy piece of advice: Buy a parts book for your engine. These can be had by CPL and Engine serial number or you can get a generic one directly from Cummins. Also get a parts book for the 6BT since some parts are interchangeable. The Cummins dealers don't work the same way as auto parts stores. They deal with part numbers, not the year and model of the vehicle. If you have a Cummins dealer nearby you be in even better shape. Don't buy parts from a Dodge stealership unless you absolutely have to. Their markup is incredible.

Linda[/QUOTE]

I'll just jump in and remind everyone that another source of parts for Cummins engines is your local Komatsu dealer (or other equipment such as Ingersoll-Rand...) since Komatsu has a strategic partership with Cummins and uses a lot of thier engines... I have a Cummins distributor just down the road from me, and several heavy equipment dealers and the Komatsu one will sell me a Cummins branded part in a Komatsu box for less money than any of the others... They also don't mind playing with the parts computer to get the right part based on the number that I pull from my Cummins manual (they do get changed from time to time...). They also really like my 4BT powered M37...

Thanks for sharing the info on all the conversions.

[JimmieD]

Thanks, C/G! Let's face it, every little bit helps nowadays. It has been pointed out to me that some justification for the rather extreme prices is in the fact that you're at least getting quality in the Cummins parts. However, as Linda said, there's no excuse whatsoever for Dodge's typical and ridiculous markups!

You know, with all of these automotive manufacturers supposedly struggling to make it I wonder why they don't get a clue on how to increase parts sales 300-500 fold: LOWER YOUR PRICES, DUMMIES!

JimmieD

[Gordon Maney]

I'll just jump in and remind everyone that another source of parts for Cummins engines is your local Komatsu dealer (or other equipment such as Ingersoll-Rand...) since Komatsu has a strategic partership with Cummins and uses a lot of thier engines... I have a Cummins distributor just down the road from me, and several heavy equipment dealers and the Komatsu one will sell me a Cummins branded part in a Komatsu box for less money than any of the others... They also don't mind playing with the parts computer to get the right part based on the number that I pull from my Cummins manual (they do get changed from time to time...). They also really like my 4BT powered M37...

Thanks for sharing the info on all the conversions.

Very interesting about the Komatsu source....

[CGarbee]

Yep, more info than you need to know:

The joint venture is known as "Cummins Komatsu Engine Co." and has engine assembly plants in Seymour, Indiana and Oyama, Japan. The joint venture was set up in 1993 and has resulted in Cummins becomming the exclusive engine supplier for Komatsu mining equipment. Komatsu Cummins Engine Corporation (KCEC) joint venture also includes manufacture of B and C series engines.

It is my understanding (not confirmed) that the engine blocks used by Consolidated Diesel Company (another Cummins joint venture, this time with CaseNewHolland) at the plant in Whitikers, North Carolina (ok, they call it the Rocky Mount plant, but it is actually located in Whitikers...) are from Komatsu...

[JimmieD]

Why, it's almost as if Komatsu, as opposed to Daimler/Dodge, actually wants to do something to EARN your business and keep you coming back? What a concept.......

[donnercruz]

How's the progress?

I just found this thread while considering putting a diesel in my '66 Town Wagon.

Any pictures?

Where in CA are you?

[MoparNorm]

He is in Central CA, his conversion is complete, it works great and he will be up any minute to tell you about it,...over.....