Donald K. Foote was a well-known modeller and AMA member who often served as a contest director at AMA-sanctioned events. His 177 page hardcover book "Model Airplane Engines" was first published in 1952, with a revised edition appearing in 1957. Both editions were published by the Ronald Press Company of New York. Foote also wrote a major work entitled "Aerodynamics for Model Airplanes", which was published by the same company. 

The stated purpose of "Model Airplane Engines" was to provide "a complete explanation of the theory, design and practical application of model engines in easily-understood terms". There's no doubt at all that it succeeds in this endeavour, although it's my impression that it goes into more detail than many modellers would really require. All aspects of model engine working principles, design factors and construction approaches are dealt with in considerable detail. There's an exhaustive and very rational section on trouble-shooting, as well as a good deal of information on fuels and an in-depth discussion of the relationships between torque, speed and power. 

The main drawback for an old Brit-head like me is the fact that the book is writted (quite understandably) with the American modeller very much in mind. There's almost no coverage of diesels, although they do get a few pages. To compensate, there's quite a good section on spark ignition operation. But there's no historical information at all, and all of the engines described are standard American types from the 1950's. 

Copies of this work seem to be fairly readily available through Amazon, eBay, etc. If you're interested in the technology of American model engines as it stood in the 1950's, this is a very interesting and informative read. However, if you just want a book on model engines in general, there may be better options.