ORIGINAL: acdii
No challenge if someone already built it. [&:] Besides if I can pick up 9 engines from swap meets of the same displacement for cheap, then make the mount and gear set, it would be a lot less expensive that way.
That a full scale radial engine will operate in the low 3000 RPM range.
A small R/C radial will opreate @ @ least 2X that, 3 x in really small engine.
A 5 cylinder radial opproximates the sound of a full scale 18 cylinder radial quite well.
[youtube]http://www.youtube.com/watch?v=_vfdhFYmmlo[/youtube]
Even better than an actual 18 cylinder R/C engine IMO.
[youtube]http://www.youtube.com/watch?v=PWlB_s_hkQc&feature=player_embedded[/youtube]
The secret is getting a low idle speed/operating RPM range. An "oversquare" engine geometry W/spark ignition is one of the best ways to acheive that.