The Foden High Speed Diesel Two Stroke engine began development during the latter years of WWII and the reason for Foden to design and build their own powerplant was a simple one and something that would also reappear in later decades of vehicle manufacture. The war years had increased the productivity and manufacturing capability while turning out vehicles for the Ministry of Supply and Defence and to enable this to be kept up post war it was felt Gardner’s ability to meet future engine requirements for the company as well as other makers using the Patricroft engines would effect this. An engine had been tried previously in 1938 named the ‘Nemesis’ a four cylinder oil engine based on the Gardner 4LW, however this experiment did not hold up to the better fuel consumption, starting reliability and noise emission of the Gardner. The failure of this earlier attempt could be the reason Foden designers decided to go for the Two Stroke, a one cylinder test engine proved successful so production started on a four cylinder Two Stroke and it was ready in 1945.
It developed 84 bhp at 2,000 rpm and weighed less than 1,000 Ibs due to the use of cast aluminium crankcase and cylinder block. The FD4 Mk 1 was followed by the FD6 six cylinder two stroke developing 120 bhp at 2,000 rpm, 350 Ibs/ft Torque at 1500 rpm and weighed under 1,200 Ibs, while the equivalent Gardner 6LW developed 112 bhp at 1,700 rpm with 358 Ibs/ft of Torque at 1,300 rpm but weighed 350 Ibs heavier than the FD6 installed. The job now was to build up the same customer confidence as the Gardner engine range did and Foden sales teams set about this. Marine examples of 4, 6 and 12 cylinder engines were also developed and the commercial engine developed over the years into the Mk III FD6 of the Sixties which most of us on this site recall in Foden’s of the period. Foden obviously felt producing their own engine was worthwhile since the early model and sold well in the UK and especially on overseas contracts. Hope you found this useful GUY Big J. Franky.