The Perkins 4.236 diesel marine engine is considered to be workhouse in the boating industry. Though the Perkins 4.236 engine is no longer manufactured, the engine's popularity and reliability have caused many engine manufacturers to begin selling and re-manufacturing the 4.236. Also known as the Westerbeke 40, the Perkins 4.236 was introduced to the boating world around 1970.
The Perkins 4.236 diesel was an 84-horsepower engine while at 2,800 RPM. The engine's ability to produce 84 horsepower at such a low RPM allowed marine-going boaters more functionality and raw power at low speeds.
The Perkins was an in-line four-cylinder motor that was fresh water-cooled with a direct injection fuel system. The engine was a four-stroke engine, making the need to mix oil into the diesel gas unnecessary.
Th Perkins 4.236 was a heavy motor, weighing in at around 499kg. When the reduction gear option was added, the weight climbed to 519kg.
The compression ratio for the Perkins was 16:1 and was governed mechanically. It employed a rear rotary distribution for its fuel pump, and its cubic capacity was measured at 235.8 cubic inches.
The Perkins 4.236 valves are set at a bore of 3.875 inches and a stroke of 5.0 inches. The engine uses a set of intake and exhaust valves for each of its four cylinders, making a total of eight valves.