It is the MG EX181 engine fitted with a Shorrock supercharger. Which on 23rd August 1957 with Stirling Moss at the wheel, running on 86% methanol laced with nitrobenzene, acetone and sulphuric ether reached 245.64mph .
What a great find Andrew, thanks for that. Another part of the story connecting my favorite MG characters, Captain George Edward Thomas Eyston, Goldie Gardner and Stirling Moss.
It's an MG?? D'oh 
That's as far as I got without googling(cheating).
Cru5ty googling is not cheating it's finding out about the wonderful world of MG's. The idea of the MG T-Bar Quiz has always been to learn more about the fascinating machines, history and community we are all members of and to have a bit of fun on the way.