3126 slotThe Cat 3126 engine is an in six-cylinder, four-stroke diesel engine. It features a displacement of 7.2 liters (439 cubic inches) and operates on a compression ratio of 16.5:1.3126 engine applications Caterpillar 3126 engines are used in many work applications such as delivery trucks, dump trucks, garbage trucks, snow plows, flatbed trucks and school buses.