Was there a Whirlwind II? I note on p.38 of BSP :
"Some alternative powerplants were suggested. Roy Fedden at Bristol pressed strongly for the installation of two radial engines but Westland knew that fitting larger powerplants was impossible. The original concept had been to build the smallest possible fighter compatible with two engines and so its stucture was neither roomy enough nor strong enough to take anything larger."
However on p.42 re: Spec. F.6/39
"This covered two projects developed from the Whirlind and powered by Rolls-Royce Griffon engines ..... (there was also a version with Merlins).
F.6/39 was soon overtaken by new requirements and these projects were abandoned."
In comparison with the Whirlwind's 45 ft. span, 250 sq, ft. wing area, and weight of 8,000 lbs. this project aircraft came in at 60.5 ft., 450 sq. ft. and 16,200 lbs.
It is curious that the Gloster entry in the twin-engined contest was powered by twin Bristol Taurus engines and achieved a similar maximum speed as the Whirlwind, of 360 mph. When, after a landing accident, it was re-engined with lower-powered Taurus engines and then 885 hp Peregrines (comparable to Whirlwind), max speed dropped to 330 mph. The Gloster used thick wings. The Bristol Beaufighter was a re-fuselaged Bristol Beaufort with engines changed from Taurus to Hercules. And yet, the Beaufighter struggled to get ove 300mph due to the thick wings. Somehow, the Beau (Beaufighter, G.W.) was extremely popular.
Getting to personalities again, the life and career of Sir Roy Fedden along with his co-hort draughtsman, Leonard Butler, is very curious in that he was unhappy with company management and government decisions which affected his work and led to his departure in 1942 from the company that he built. The Hercules engine never reached it's true potential until post-war commercial engines were built with rear-facing exhaust and direct injection. Centaurus ditto. Furthermore, Bristol engineers were lent to Napier to develop the sleeve valves on the Sabre engine, at government suggestion, which couldn't do Bristols any good. And it turns out that the Centaurus was superior to the Sabre, and didn't burst into flames if you sneezed. Just sayin'.