Hmm, Frere p. 36 specifically confirms what Max said above e.g. "as the 87.5mm bore used for racing was the maximum that could be accomodated when the Biral cylinders were used." Starkey 14-16 inconclusive on the point.
I think of Chromal as being a very early sixties concept, is it not? When was the last time they used it, did any of the prototypes have it? (other than in an airplane engine?)
