As a manufacturer, in contrast to assemblers using largely bought-in parts like its Sandbach neighbour ERF, for example for most of its existence Foden had the distinction of being vertically integrated. This was a legacy of its steam wagon garage door opener chamberlain In the steam era, an engineering business was typically obliged to produce virtually everything itself. In its original Mkl form, output of the Roots-blower supercharged 72-litre FD4 two-stroke was 84bhp.
The 2-litre Mk6 development introduced in the early 1960s produced 98bhp. As a consequence, in deciding to build its own diesels, Foden was able to draw on core engineering garage door opener chamberlain and foundry and associated resources. Together, these enabled it to manufacture not only engines, but gearboxes and other automotive units almost entirely in-house. Fodens interest in developing a two-stroke range began during the first half of the 1930s.
The first Foden diesel truck was delivered in 1931, powered by a Gardner 5L Given its tradition of self-sufficiency, the idea of using proprietary engines obviously rankled. The decision to take the two-stroke route was influenced by the fact that others had a 10-year lead in four-stroke diesel development, whereas two-strokes were an under-exploited niche offering potential unladen weight savings and thus a competitive edge. To advance the project, a licence was taken out for a patent filed by the diversified aircraft-to-battleships Armstrong Whitworth group. The objective of two-stroke development was to offer an garage door opener chamberlain to the Gardner 6LW that delivered comparable power but gave a significant saving in vehicle unladen weight. After experimenting with an initial singlecylinder test engine, a five-cylinder layout was considered.