So, in this, the fifth installment of Horsepower Road Blocks, we find ourselves back to the good ole reliable powerhouse of the light duty truck market commonly referred to as the 12 valve. The 12 valve is the first generation of the 5.9L Cummins inline six cylinder.
The 5.9L is part of the "B" series of engines designed and built by Cummins. The B series has a displacement of almost one liter per cylinder. The engine came in two configurations, a 5.9L inline six cylinder and a 3.9L inline 4 cylinder. The B series engines have found their way into a wide range of applications including buses, construction equipment, boats, generators, military vehicles, commercial trucks and light-duty trucks. Its first commercial use was in 1984 as an agricultural engine.
These engines were designed to be extremely reliable with very little maintenance. Some of the key features in these engines are: Gear driven cams, mechanical injection, mechanical lift pumps, overly stout rods and the block is a deep skirted block.