[burgundyja]

what prop is everyone using on the IO-390? any fixed pitch props? any 2 blade hartzel cs? if so what airframe and what do you think of the prop would you buy it again? i really like the 390 but i dont want to spend 10k on a mt cs prop.

 

[osxuser]

7497 hartzell would be the CS of choice. I think some people have put on a WhirlWind, but I don't know which one.

 

[MCA]

I have a 7497 in mine.

 

[RV7Guy]

Whirlwind 200RV

The 200RV is rated for well over 200 hp. Use with confidence. It will be the smoothest prop you will ever experience.

 

[vmirv8bldr]

WW200RV for me

I'm not flying yet, but the WW200RV has been blessed for the IO-390 by the guys at WW.

 

[DanH]

<<the WW200RV has been blessed for the IO-390 by the guys at WW.>>

Does "blessed" mean "We think it should work" or "We did a certification-standard propeller vibration survey"?

 

[vmirv8bldr]

Call them to be sure

By blessed, I mean I called them and they said it would easily accomodate that powerplant.

I'm not a spokesman for WW, so call them for technical information. The prop was designed to be optimized for an RV-8 with a 200HP engine. I called and asked if it would handle the 210-215hp area of the IO-390. IIRC, they said it would have no problem in that application, and that it would comfortably handle above 240hp.

(This does not apply to all WW props, I only inquired about the 200RV.)

The friendly folks at American Propeller or Whirlwind may be able to chime in regarding tested limitations, etc. My advice is to take their word over mine. I can check when I get home, but I'm 90% confident the operators manual says that the prop MUST be dynamically balanced prior to flight use.

 

[DanH]

<<..the operators manual says that the prop MUST be dynamically balanced prior to flight use. >>

A propeller vibration survey has nothing to do with propeller balance. A typical survey involves placing many strain gauges on the hub and blades. A variety of ground and in-flight conditions are checked. In general, you're looking for resonant blade modes.

The other approach is to sell it as "experimental" and get nice folks to fly it around until you find out how many hours it takes to break it. Just set the TBO kinda short, and require that all props come back to the factory for inspection. There are certain drawbacks to the method.

Hartzell and MT do formal surveys. Others might, and if Whirlwind does, I'd love to hear about it.

A little reading:

http://rgl.faa.gov/REGULATORY_AND_GUIDANCE_LIBRARY/RGADVISORYCIRCULAR.NSF/0/4cfce91224a85b8586256acd00707ebb/$FILE/ac20-66a.pdf

 

[JetA4GA]

According to the vibration survey carried by a popular brand manufacturer, one day on a propeller installation program on a Lycoming IO-360 (180 HP) modified with a different exhaust system I ran on a situation where the highest blade root stresses were not at Max power but at throttle back.

So, recommendations from a reputable propeller manufacturer that knows about your powerplant installation specifics is a must in my book...little changes can make a big difference and maybe not where one would expect it at first sight.