The 6354 was a heavy-duty diesel engine produced by Perkins. It used a straight-six design, meaning the cylinders were arranged in a straight line, rather than in a "V" form. The engine had a displacement of 5.7 litres. Although the engine was first manufactured in the 1960s, its production lasted for decades.
The Perkins 6354 had a total displacement of 354 cubic inches. It had a bore and stroke of 3.875 inches by 5 inches, while the compression ratio was a large 16 to 1. The engine redlined at 2,800rpm and had a maximum power output of 120 horsepower at 2,800rpm. The max torque was 260ft.-lbs. at 1,750rpm. The turbocharger used an air-to-air charge cooling design.
Seeing that the company had a gap in their medium-duty engine line-up, Perkins designed the 6354. The engine had a few notable design characteristics. For instance, Perkins equipped the engine with a small jackshaft driven by the timing gears, as well as a new oil pump that was driven by a quill shaft. According to AllPar, "The advantage of this was being able to run auxiliary equipment like compressors and pumps at engine speed, with simple couplings."
Another notable design feature was the use of a low camshaft with longer pushrods with a compact timing case. This reduced the overall length of the engine without compromising engine displacement. This size reduction of the engine meant that the 6354 took up the same amount of engine space required of a gasoline V-8. The use of a CAV pump helped reduce pollution.
The 6354 was the first Perkins inline-six to be direct fuel injected. The engine was first produced in 1960 and later modified to increase power in 1962. In the mid-1960s the turbocharged version became available for agricultural, industrial and marine equipment. Despite its quality design, American sales of the engine waned. The engine was further modified to increase displacement to 372 cubic-inches. In the 1970s the engine was chosen over Mitsubishi, Detroit Diesel and Caterpillar engines to be used in the Dodge/Commer 100 commercial-truck line. Amazingly, the 6354 engine series was manufactured until 1996. During its 30-plus years of mass production, more than one million 6354 engines were produced. In 1998 Perkins was bought out by Caterpillar for £0.8 billion.