RE: Riley Sprite

Hmmm... You are probably thinking of the first MG Midget, introduced in
1928... The Austin 7 was introduced in 1922 with a 750 engine, but that was
a road car, albeit successfully used in racing. There was an awesome racer
developped from the Austin Seven in the mid thirties- twin cam with
supercharger... Power was rumored to be over 110 hp!

Jacques LC

Ed wrote:
  Austin had a 750cc racer in 1928, but I have no idea if it was a 'Sprite'.