My first "large" engine, c.1952, was a Fox .29. It was one of the newer ones with the 6-bolt head. Flew it all through the '50s: Ringmaster, Circus King, Yak-9, and so forth.
Many years later, 1989 or '90, the late Tom Lay gave me an old 4-bolt, sand-cast .29 which I used in a Box Car Chief (FM, Dec. '90) for dozens of flights until the crank broke in-flight at a contest in Whittier Narrows, CA. Prior to that, it placed well in OTS events in Tucson.
The Fox .29 was a nice engine. Highly modified by NJ's George Moir, it powered him to the win in Class B Team Racing at the '54 Nats. (Was a feature article in an old issue of M.A.N., back when they still featured real model planes.) As a kid, I launched test flights for George in Haddonfield, NJ. Ahhh....that fuel's "shoe polish" aroma!