“Cosworth in the eighties and Ferrari in the nineties also tried but rejected desmodromic valve control.”
Source: Classic Grand Prix Cars : The Front-engined Formula 1 Era 1906-1960 by Karl Ludvigsen (cop. 2000) p. 31 (in section “Introducing Desmodromy”)
In our book “desmodromie” (cop. 1990) we mention Cosworth with regard to DVG on three places and we discuss two Ford patents also (see pictures).
P. 52/53 we discuss the patent of Peter William Bothwell (see first left picture). In those days there were rumours telling this patent was intended to sell to Cosworth.
P.79/80 we discuss the cooperation between Cosworth and Ducati (Bordi) in 1987. (design of the 4 valve 851) From Bruno de Prato (in Moto Technica no. 1 ’87) we learn that Cosworth extensively tested their desmo-motor but eventually closed the subject. The Cosworth engineers regarded the 4-valve desmo-cilinderheads thermodynamically ideal. It could make the DFV/DFY 3000 F1 engines competable again, but the mechanical complexity and the limited space would bring too much complications.
From John Blunsden in his book “The power to win : The design, development and achievements of the Ford Cosworth DFV, DFL and DFY V8 racing engines”, we learn that the desmo-programme was initiated by Duckworth in 1979, prompted by the difficulties in trying to solve the valve spring surge problems. The desmodromic programme was cut short because of underestimation of the subject and doubts about the significance with regard to cost and necessary man-years. It’s a pity that there is no drawing or picture of the desmodromic test rig in this chapter. From the patentfigures – although they are of later (’83; ’85;’86) date – we may conclude how the tested system(s ?) could have looked like. We are waiting patiently for the confirmation (in text, photographs and drawings) from Cosworth or from other good authority.
More research to be done.
Patentdrawings: First pic on the left: Bothwell, Peter William in GB2166799 (1986-05-14) = US4858573 [Classification = Group 4]
First pic on the right (single cam): Ford Motor company Ltd UK in GB2135386A [Classification = Group 2]
Last Pic on the left: Ford Motor company Ltd UK in GB2135386A [Classification = Group 5]
Last Pic on the right: Ford Motor Company, Michigan in US4763615 [Classification = 7B]

bothwell0     ford0

ford1 ford2