To: bingoboy
I did a search on Pobjoy engines on Google and based on what I found I doubt seriously if they were used at the Cleveland air races. However when I attended the races in 1937 I was 61/2 years old so I was not very aviation literate. In the 46 and 47 air races the unlimiteds were mainly US Military aircraft and the smaller categories had mainly flat opposed engines made in the USA.