This is Meggitt Defense Systems Ltd manufacturer of pilotless aerial vehicles (UAVs).

“Meggitt Whirlwind”

-It has a single rotor, and can be used as a puller or pusher.

-It gives 41.5 HP of power at 7,800 rpm. With a carburetor can reach an altitude of 6,000 meters and with gasoline injection it can reach 8,000 meters.

“Two new views of the same engine”

From Appendix 10: The engines were manufactured by “Cross Strip Aviation Ltd”. The V.30 model is a 4-stroke 2V (B&S base) with its own gearbox of which the parts are shown below.

“Gearbox parts”

-We see different drum diameters for as many reduction ratios.