I was greatly interested by your article in this month’s Motor Sport and have been pushing calculator buttons since reading it, with the following results:
114 x 114 gives 6,982 c.c. and not the quoted 7,036 c.c.
114 x 121 gives 7,411 c.c. which is again not the official figure but is surely why the BARC programme notes showed 7,410 c.c. (allowing perhaps for slide rule error).
As you indicate, Mr. Sanderson was well able to do his sums and I suggest that he was baffled by the results noted above and decided to measure his own engine, which for some reason came out at 114 x 119, 7,288 c.c.
I am not familiar with the 40/50 engine but would like to know if the pistons are slightly domed, or of any other features that could have caused incorrect measurement.
Reverting to the true dimensions, I suspect that these were originally specified in inches thus:
4 1/2 in. x 4 1/2 in. (114.3 a 114.3) gives 7,036 c.c. as quoted.
4 1/2 in. x 4 3/4 in. (114.3 a 120,7) gives 7,430 c.c. (7,428 quoted).
With regard to the other conundrums, a prudent man might leave an expensive R-R radiator cowl at home, out of the way of flying stones, perhaps thinking of future reconversion as a touring car, which might also account for the unmodified handbrake.
Thank you for the mental and digital exercise.
Merton, Peter Wood