Hi!
10-12 years ago we flew Sport 40 pylon over here in Sweden , using 80/20 fuel.
MVVS was slightly better than both Irvine Sp .40, Rossi Q-500 and Webra Q-500 (we ran those engines with their own mini-pipes).
Then came along the Super-Tigre Q-500 engine.... and bye bye MVVS!