Rotax Rick should be happy to hear his 670 engine with a 7” smaller prop…matched the significantly more expensive 914, and spanked the twice as heavy Sub 2.2.
Western Rotorcraft 5 July, 2013
Number Aircraft Engine Prop Dia. Blades Thrust ISA Notes:
N501AG Calidus Rotax 914 HTC 69” 3 380 490 (UL)
Vancraft Rotax 503 Ivo 59” 2 180 232 With air cleaners (UL)
Vancraft Rotax 503 Ivo 59” 2 215 277 Air cleaners removed
N920CC Monarch Rotax 670 Powerfin 68” 3 340 438 670 by Rotax Rick
N39GB Vortex Rotax 670 Sport Copter 68” 3 370 477 670 by Rotax Rick
N541KP (PPC) Rotax 670 Warp Drive 62” 4 380 490 670 by Custom Pipes
N4242S RAF 2000 Subaru 2.2 Warp Drive 68” 3 330 425
Comments
The left number was at 6,500' and the right number was calculated to what it would have been at sea level.
Sweet, I had been interested in these numbers. Hard to get an exact feel for which prop configuration gives best thrust as there are too many variables changed between them. How much do you think the fuselage in front changes airflow to the prop (static or in the air)?
Here are some good prop comparisons:
http://www.stolspeed.com/id/62
Static only tells part of the story...mainly important for short ground roll and low speed, like with an airboat, hovercraft, or PCC. Less so with airplanes and fast trikes.