This was a standard Hornet 60 whch was upgraded through the installation of a factory kit featuring revised upper cylinder casting, backplate and venturi components. It also required the cutting of two additional transfer openings in the standard Hornet cylinder sleeve. The kit was sold from late 1948 through to early 1950. It was a response to the appearance of the Dooling 61 and the McCoy 60 Series 20. One of these engines was the first to reach 150 mph in C/L speed, but it subsequently failed to keep pace. An article discussing attempts to keep the Hornet engines competitive may be found on the late Ron Chernich's "Model Engine News" (MEN) web-site.