1951 3100 4BTA Cummins

[kirsch11]

So this project has been in my head for about 5 years when I was in college. I've been around AD trucks my whole life. I believe at one point my dad and brother had a combined 11 if I remember. Once I graduated college 2 years ago my dad gave me one of his parts truck to toy around with.

I never wanted to keep the stock and everyone is doing 350's or LS swaps, I haven't seen many with the 4cyl Cummins before especially in my area. Before the project started I found a 1984 S10 standard cab long box for the frame conversion. It had a v-6 with a 4-speed that I planned to keep in it for awhile. I had never driven a stick shift before so I had to learn pretty quick to make the 4hr drive home. The very day I got home I started taking it apart and was down to the frame in about a week or too. I was able to sell all of the parts that I wasn't using and got the frame for a profit. I bought a Code504 kit instead of building my own. My reasoning was that if I got into an accident all I needed to do was to unbolt the pieces and put them onto an new frame instead of cutting and then re-welding.

I had all of the components on the frame when I found a 1995 Fedex Van that had a 4BTA P-pump with a T-19 transmission for sale in my area. My dad and I went to pick up the truck on New Years Day. That was all fine and dandy but the drive home was -35 degrees and my dad was driving it home with no heat. Let's just say that we was pretty upset. As soon as we got it home I started taking it apart and had the engine out in about a week. I sold the remaining parts and got the engine for less then what I would pay somewhere else.

I had the engine running in April of last year after trying to figure out how to adapt the wiring harness. I bought an EZ Wiring 21-circuit and had parts of the Cummins harness as well. It took me about a month to draw up a diagram to make everything work. I had it just about driving at the beginning of June but I had some brake and tranny issues as well as a friend that was helping me out after work pass away suddenly. All those things together didn't help since I wasn't able to look at the project for some time. I finally got it running in the beginning of August and and it has about 220 miles so far.

The engine specs are that it is a 4BTA P-pump, it makes about 125HP and around 250 FT LBS stock. Hopefully this spring I can bump that up to around 400 HP and 800 FT LBS reliably. I also need to find an 2wd NV4500 since the T-19 won't be able to sustain that amount of power. I'm putting new rims and tires on as well, the rear tires will be 335/25R20's and the front 245/30R20. I'm going with an Aero dirt track style wheel.

I have had to come up with a lot of different ideas to get the engine to work in the frame and cab as well. I took inspiration from skymangs S10 Swap how to page. My phone did a factory reset in July so I lost the majority of my build pictures ;( If anyone has questions please feel free to ask and I'll do my best to answer and take pictures for you.

[mongocanfly]

Nicely done kirsch....you are correct...not many diesel ADs....with the nv4500 you'll want to run a fairly low rear gear...not sure what you have in now...with a 26" rear tire and the nv with a .7od...and I'm not sure about what a 4bt does rpm wise... here's a rpm calculator.....http://www.csgnetwork.com/multirpmcalc.html

[Ace61]

Nice build, I also have an AD truck. 1954 chevy 4400 i have a 4bt from a p30 step van. Did you use the intercooler from the step van? or did you buy an aftermarket?

[kirsch11]

mongocanfly - i have the stock S10 3.08 gears in there for now. The RPM's right now are around 2500 i believe. I'll be putting in 4k springs this spring and that will bring it up.

Ace61 - I used the stock intercooler from the van, I'll try and find pictures or take new ones.

[kirsch11]

Ace61 - Here are some pictures.

[mongocanfly]

With 3.08/26in tire/1.1 4th gear at 65mph your turning 2587ish rpm...
I went back and fixed the bad link above to the rpm calc...

Sucks about you losing your pics....

[Ace61]

Wow your intercooler is short mine is tall. Nice fit on yours! What issues did you have making a wiring harness?

[kirsch11]

Thanks man, the nice thing about the NV4500 is that it was an "overdrive" .73 gear.

[kirsch11]

ACE61 - I actually cut 2 or 3 cores out of the bottom and tig welded bottom plates. I was just trying to figure out how to combine the 2 harnesses and what I needed. Instead of using the fuel shutoff solenoid I used the "T" throttle cable for my shutoff. When it is pulled out the engine has fuel and pushing it in kills it. I'm trying to think out something else for the "C" choke cable. Was going to use it as a battery kill switch but went another route.

[kirsch11]

Here's what I came up with the for the battery kill switch. Bought one from Runnings Farm and Fleet and shaved it down to fit the inside of the stock gas cap. I just cut the original filler neck and made a a bracket that bolted behind the door striker plate. It's just a quarter turn to the right to have power and then back to kill.

[kirsch11]

Here's the mounting. I used Trique Manufactoring latches, well worth the money.

[mongocanfly]

Very slick kill switch idea...I was looking at the pic with it stuck thru the fill hole and I thought itd be cool to use the cap for a switch handle....then the next pic there it was....

Yes the nvs are great transmissions...ive got 2 of em...with the .7 od and everything else the same your rpms would drop to around 1811 at 65...

[kirsch11]

mongocanfly - Thanks it turned out nice and everyone asks what I'm doing when I turn it. Ya, that's roughly where I would like to be for cruising.

[kirsch11]

All of the Hot Rod guys or my dad calls them the Good Ole Boys just shrug at me when they see it. They think its pretty good and call it a tractor. I also tell people that the engine has a really bad knock but I'll drive it until it blows. They usually believe me until they see a little black smoke come out of the fender side dump that I designed.

[mongocanfly]

The 4bts are hard to find around here....the jeep guys snatch up em quick...

[kirsch11]

Ya, they are hard to find here as well. If your looking for one I've heard of them on luggage karts at airports or other equipment there.

[Brads49]

Very cool project! The 4bt is a great little motor! Who's gauges are you using? They look cool!

[kirsch11]

Brads49 - They are from speedhut. I really like them and would recommend them to anyone.

https://www.speedhut.com/kit/GR4-DUA...er,-Quad-Gauge

[Ace61]

Did you go for the GPS speedo from speedhut? I liked their gauges but wondered if no speedo cable worked very good?

[kirsch11]

Yes, I have the GPS. it's amazing but takes about a minute to calibrate to the satellites. You can do a lot of things with it. The link that I posted shows what it could do. I went that route because I knew that I would be changing trannys. The picture with all the gauges has the receiver which is black and I have it placed in the front of the cab. You dont want it obstructed by any metal objects.

[joedoh]

nice work, I bet that thing hums.

[kirsch11]

Joeduh - yes it does.

[Purcell69]

That is a very nice fit! Keep up the good work.

-Joe

[kirsch11]

Joe - thanks, the 4bt is close to the same length as the chevy 350.

[joedoh]

Originally Posted by kirsch11

Joeduh

freudian!