RCU Forums - View Single Post - Is it a phenomenon of these little 2-strokes that until well broken in, they will not turn a larger
Old 09-28-2009, 01:45 AM
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DarZeelon
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Default RE: Is it a phenomenon of these little 2-strokes that until well broken in, they will not turn a larger


ORIGINAL: rsieminski

2.5/20(50/50) MA 10x4 17K
Rick,


Before I comment on the subject, this is a stark warning!

This prop at this RPM can present a mortal danger.
Master Airscrew dictate an RPM limit for their GFN props, as stated [link=http://masterairscrew.com/images/selecting_a_prop.pdf]right here[/link].

For a 10" diameter prop, the limit is 16,500 RPM, which is around 15K static, if you allow for unloading in flight.

A blade flying off can take out an eye, destroy your model and can do nothing positive...



As to the subject; I can tell you that MVVS ABC engines would typically gain substantially in top-end RPM, from the time break-in is 'declared' completed...

Over the first 4-10 hours of use (less for smaller engines and more for larger ones), the engine will typically gain 400-1,000 RPM on top.


I guess what allows this top-end gain, would also have an effect on the engine's ability to spin larger props, without straining itself excessively...