Engine size, Proppeller, RPM
 

Does anybody have a "document" stating engine size, prop size and RPM with stated prop?

I believe it could be handy for those of us YS lovers trying to decide which engine to put in a particular air frame. I feel RPM on "X" prop is more useful than a horse power number. Maybe this could be integrated with the HP numbers in the other thread or it could be a stand alone thread.

With the above said I know there are various props to be used with each engine and not all props work with all air frames.

Thanks!

Ken.

Not YS specific, but helpful nontheless:

• Try this? Prop-Power calculator - MVVS - Docstoc.com
  
  www.docstoc.com/docs/149361600/Prop-Power-calculator---MVVS
  EDIT: Seems that site is down. Try this:

http://www.rcfaq.com/RPMSTATS/RPMINDEX.ASP

Ken, not sure how this would be done as far as actual prop sizes as there is such a size range that will work for each engine and different makes of the same size will load the engine differently as well. My rule of thumb is to prop to not exceed the following max RPM on the ground.

53, 63, 70. 12,000

91, 110, 115, 120. 10,000

140, 160, 175, 185. 8,500

I guess I was thinking a middle of the road prop (using the MFG recommendations) maybe standardizing on a brand such as an APC as they should be fairly consistent. With that data it would be fairly easy to substitute a YS for another brand of engine or understand which YS would be appropriate for an airframe.

OR.... Maybe I'm just trying to reinvent the wheel:confused::o

Ken

Ken, too many veriables, example a YS 115. For warbird racing we run 40% nitro and a 14x13 or even 14x14. You wouldn't want to run that same combo on a 72" Extra 300. The Extra would be looking for more like a 16x10 or 17x8. The best way to select the prop is take into consideration the airplane, flying style and drag. This will lead you to selecting an appropriate prop diameter then just select the pitch that keeps you in the rpm range for that specific engine. I would use this formula on just about any engine, the difference with YS is that you will have to adjust prop load for the additional power. What load works well for a Saito will be over revving a YS.