I've flown a medallion 15 on a larger and heavier (one would hope) airplane than an Acromaster. As I recall, the Medallion 15 turned a Cox grey 8 x 4 around 13,800 on 10% nitro Sig champion fuel and the Medallion head. I would think you would have a pretty fast airplane on 52 ft lines. I've flown a TD 09 a lot on a Shark 15 and a Jr Flitestreak. 57 ft 012 lines. Still fairly fast on 10% fuel. The TD 09 likes the Cox grey 7 x 3.5 prop which is a rare find these days. I'd run an APC 7 x 3 if I did not have the Cox prop.

Jim