Whether the 100 hp Isotta Fraschini was designed, probably by Stefan’, for the 1909 GP formula I don’t know, but thanks to recent research in the Fiat archives by Tito Anselmi some interesting information has come to light about the S61 GP Fiat designed in late 1908, and the 1911 GP de France winner also mentioned in Kent Kerslake ‘s letter.
The original engine drawings for the 10-litre S61 show that it was designed by Ing Guiseppe Coda who worked under Stefanini at Isotta Fraschini in 1905. Alfieri Maserati was also there, Coda and Maserati maintaining friendly relations from that date until after their collaboration at Diatto, when Coda joined Citroen.
G.C. also designed in late 1909 a 4.4-litre version of his OHC 16 valve Type 61 engine. designated S53 It was probably one of these engines fitted to a production chassis. and perhaps running in the Touring class. that won the 1911 GP de France.
Photos of Hernery during the race show clearly that it wasn’t a 10-litre as the bonnet isn’t high enough to cover the massive engine of the larger car.
Chelmsford. FRANK LUGG Essex