Here’s a great close up of Louis McNair in the Hirth F23 powered Mynah.
Wallace says ‘It is running very well, as expected. The 72 x 36 inch prop driven with a 2.7 : 1 reduction is proving ideal. At the time I ordered the F23 I tried to buy the Hirth belt reduction with that ratio but was told it was not produced. A pity because the big prop gets a very good grip!’
Thanks for the photo and feedback Wallace!