Hi Pat, Phil in Clarence Gardens Adelaide South Australia. Am building a WM20 to go salt lake racing. Am using twin spark & big bore/M21 crank to get capacity. Loved the story, thanks.
Just found a 1954 m20/m21 bsa engine price list for cylinders m20/m21 66-88 £7-0-0 and AA cylinder £8-15-0 what's the difference are these a better casting mal.
