BTW, the engine test results covered nine props. There were two 10", three 8", and four 6".

The two 10" props showed the highest thrust and the two highest speeds.
The three 8" props showed the next highest thrusts.
The four 6" props showed the lowest four thrusts.

There was some overlapping of speeds with the 8" and 6" due to the fact there was way more range in diameters within those props. For example, the 14x8 prop would give 85mph as would the 13x6 prop. The 13x6 would have to spin over 30% faster to do it however. Overall, however, the speeds followed the pitch. For the most part, because the tester chose appropriate props for the engine.