In every time zone and every work site, every farm and every forest, chances are good that you’ll find Cummins B Series engines hard at work. Millions of B Series engines are currently in use, from paving compactors to telescoping material handlers, tractors to mobile generators. Our mechanical B Series engines are small enough to fit the equipment but big enough to handle the job. Highly reliable, durable rotary fuel pumps deliver a steady stream of pressurized fuel for strong performance across a wide range of environmental conditions. Whether you need a low-horsepower engine with a flat torque curve or a little more horsepower with a sharp torque rise, you’ll find it in a Cummins B Series. Three different models are available: the four-cylinder B3.9 and B4.5, plus the 6-cylinder B5.9.