King 140RV
 

King 140RV, 136cc rorary valve boxer.
Exhaust: KS 90-5 canisters.

Fiala 30x16 2-blade: 5100 rpm
3W 32x12 2-blade: 5000 rpm

The 3W provided poor performance. Lots of noise but low speed. Measured thrust during a windy day was 23,6 kg (52 lbs).

The Fiala on the other hand performs perfectly in the air. Plenty of thrust and speed for spirited performance.

The engine is mounted on a 97" towplane weighing in at about 33 lbs, and using the Fiala prop, towing a 10,6 m (34,8 ft) Nimbus glider to 500 m (1640 ft) took 55 seconds from applying throttle. Much MUCH faster and easier than the previous tow using a G-62 powered Giant Stinger... :-)