Cummins 4BT in a full size 80's van? - Diesel Forum

Pengyou · 09-01-2008, 12:02 AM

I have noticed that people are selling the full size 80's and even 90's for cheap. I would like to get one and put a diesel in it so that I can afford to drive the thing. Several people have mentioned the Cummins 4BT as a good option to drop under the hood along with a 5 speed standard transmission that originally came with it.

The weight of the engine is not to far off the weight of the V8 that would be taken out. The size is also pretty close.

I am going to be doing 70% highway miles and 30% around town.

Will an engine like this have enough power to move my van and 5 or 6 people along at 65 mph? Will it give adequate acceleration to help me merge onto the freeway?

What are your opinions?

B-rad · 09-01-2008, 12:56 AM

It would be a sweet swap, but it will take some serious effort. But very cool.

SIC-E · 09-01-2008, 02:12 AM

thought about a 4bt in an ol' jeep, but a full size truck...for highway...? dunno
good luck with it.

B-rad · 09-01-2008, 04:13 AM

I would think that it would work fine, it would just be like a good ol' 6.9 it may take ya a bit but you will get there.

rpm1 · 09-01-2008, 08:38 AM

There is a couple videos on youtube of a cummins powered ford van.

Kaliburz · 09-01-2008, 12:25 PM

If I recall, I think the 4BT was actually an engine option w/ the GM chassis when 3rd party manufactures put a box body on it. But that may have been later models....

Pengyou · 09-01-2008, 11:28 PM

I would think...because that engine is used in UPS-type vans and are drive on highways....it should be able to move a vehicle smaller and lighter as well.

If I took an engine/tranny combo and dropped it into the van would it really take a lot of work? I am not interested in trying to make the engine up with the prior tranny - I want a 5 speed manual to take advantage of the engine's characteristics. I would not be looking at a newer engine with all of the electronic gadgets that go with it.

tlm47201 · 09-22-2008, 09:47 AM

The 4bt is great on fuel, but will vibrate your eye teeth out. If ya dont mind the vibration, it will move it fine. At Cummins, the tech center has had a really nice ton 15 passenger van running with one for a while.

Charlie · 09-22-2008, 01:08 PM

Consider a 3 point mount with relatively soft mounts for a big 4 cyl diesel. That will mitigate the vibration.
Regarding the adequacy of the motor, the Europeans and Japanese regularly use 4cyl ~4L turbo-intercooled diesels in class 4 and 5 trucks. It should be fine unless you envision yourself towing 10 ton trailers uphill at 70mph. The Mercedes Sprinter 3500 uses what, a 3.2L?

Charlie

FionaThe02PSD · 09-22-2008, 02:09 PM

It all depends on your skill level and budget. I have a buddy with a 66 Bronco and a killer 4BT in it that is right around 400HP..

Pengyou · 09-24-2008, 06:31 PM

Thanks! Is there any way to get the vibration of the 4BT softened enough to be only slightly noticeable? I have already decided to almost soundproof the interior so noise would not be much of a big deal. I read somewhere of a harmonic balancer "thingee" that could be put on the engine to dampen vibration considerably. Any ideas?

FionaThe02PSD · 09-25-2008, 06:11 PM

We put a Fluidampr on the one in the Bronco. It's still loud though...

Pengyou · 09-26-2008, 08:41 PM

What kind of noise? Is it the valve rattle? or the sounds of aspiration, i.e. sounds of air being sucked in?

Seafarer12 · 10-09-2008, 07:27 AM

It would work but It will be loud, shake like a 300lbs stripper and depending on the version you get low on power. You also have to look at what transmission you are going to run. If you are going to be running that much highway you will need over drive. Then look at cost vs reward. Cost per mile will probably equal a newer minivan. You probably wouldn't save any money on operating costs.

Forcus · 10-09-2008, 04:59 PM

If you are doing it only because of cost of fuel, be careful. Likely you could motor on for nearly forever on a fuel injected 351 vs. the cost of putting a 3.9BTA in. I'd suggest doing a spreadsheet and using current prices to anticipate project cost.... I assume you'd be using a Ford van, so would you use a GM trans? Not that you couldn't but factor in mounts, driveshaft, maybe wiring or control, etc. I could see a 3.9BTA, done right, costing $3-6k. That might buy a lot of (cheaper) fuel. How long would your payback be estimating your MPG for the stock gas van and a BTA? Right now around here gasoline is 75% of the cost of diesel. So if your mileage is only incrementally better, it would be a wash. I think I got around 16-17 mixed driving with an 89 F250 4x4 5 sp. I'd expect a half ton van to get marginally less.

Also given that you are much closer to the engine in a van than a truck I'd think sound attenuation would have to be top priority.

But if you want a diesel because you want a diesel, have at it! I "upgraded" to my 01 Dodge from an 03 Focus SVT. Totally different but fun in its own way.