Cummins 4BT 3.9L Engine: Specs, Problems, and Reliability. The 4BT engine is inline four-cylinder water-cooled turbodiesel engine in the Cummins B series. The 3.9-liter strait-four along with 5.9-liter straight-six (12 [ Read More.]
Cummins 4BT 3.9L Engine: Specs, Problems, and Reliability. The 4BT engine is inline four-cylinder water-cooled turbodiesel engine in the Cummins B series. The 3.9-liter strait-four along with 5.9-liter straight-six (12 [ Read More.]