[VortecZ]

4BT Cummins Turbo Diesel in an 05 Silverado

I finally started driving my truck and thought I would show off a little and give the details of my build. I did this engine swap so I could have a full size truck that gets great fuel mileage instead of driving some little crappy compact car. I haven’t driven this truck enough yet to check the mileage but I will report back soon. I really did the swap because I thought it would be pretty cool but I use the mileage thing to justify it.

I started with a 2005 regular cab, short bed, two wheel drive, Silverado. It originally had a 4.3 V6 with a manual tranny.

Motor: 3.9L 4 cylinder Cummins Diesel removed from a Frito-Lay step van and originally had a turbo 400 tranny bolted to it. Rated at 105hp and I’m not sure of the torque numbers. It fits in the engine bay pretty nicely. I used hydraulic motor mounts out of the step van. I had to fabricate the motor mount brackets and the cross member under the motor for oil pan clearance. I used the oil pressure sensor and the temperature sensors from the V6. I also used the alternator from the V6 with a custom bracket. I used the starter from the Dodge but wired it from the fuse box instead of letting it go through the computer. The computer would only let the starter crank for a few seconds and shut-off so I bypassed it. The biggest problem I ran into was finding a good wire to use for the fuel pump shut-off solenoid. You need a keyed on power wire to it. I couldn’t get the thing to start and couldn’t figure out why. I made a real idiot mistake by using a wire that was on when the key was on but didn’t realize it shut back off when the key was turned to start mode (these late model trucks shut off a lot of electrical things to conserve the power for the starter). I also added an intake grid heater off of a dodge. These Cummins motors use these instead of glow plugs. I made my own plates for the top and bottom of this and used the dodge relays to power it. I modified a factory fog light switch by putting a momentary switch inside of it to turn the relays on. This way, when it’s cold, I hold the fog light switch down for a few seconds before I start it.







Tranny: NV4500 5 speed manual from a 1994 1-ton Dodge along with the flywheel and adapter plate. The truck originally had a NV3500 that I figured wouldn’t hold up to the torque of the diesel. I had to make a tranny cross member to fit the larger tranny. The speed sensors (VSS) between the Dodge and the Chevy were too different for a simple signal converter so I had to make a reluctor wheel for the VSS to read. The chevy VSS reads a 40 tooth gear in the original tranny. My dodge tranny had a harmonic balancer on the slip yoke so I was able to mill 40 ¼” slots in the balancer and made a bracket to hold the sensor close to it. This worked perfectly. The next problem was the slave cylinder. The NV3500 had a small internal slave and the NV4500 has a large external slave. I wanted to use the original clutch master cylinder because the mounting of it and the clutch pedal are kinda complex and wouldn’t be easy to swap out with anything other than a larger one from a Duramax truck and they are too expensive. I ended up finding a smaller slave cylinder to match the volume of my master. I used one from a 1990 half-ton chevy. It needed a lot of modifying to make it fit this tranny but after cutting the flange, drilling some holes, and re-tapping the fitting hole for pipe threads and it worked great. I cut the end off of the factory braided hydraulic line and added a compression style fitting that had pipe threads. I had to use the dodge shifter but cut the lever off and welded the chevy lever to it so my interior looks completely stock.







As I mentioned, I just started driving it but I love it! It runs great. Only 105hp (well the pump is turned up a little) but the torque is awesome. It will smoke the tires in 2nd gear and bark them in 3rd. It doesn’t vibrate bad at all like other 4BT owners have complained about. It is a little loud compared to the gas motor but I don’t mind it and I don’t think it is any worse than an old 12 valve Dodge. My next plans are getting the A/C compressor bolted to it (using the original one from the V6) and adding an intercooler.