Brodhead Pietenpol Association

Original Posted By: michael list
>>> Doug Hunt 11/16/97 06:46pm >>>If you are going to use the corvair engine,i would consider using anadjustable prop such as the "WARP DRIVE" carbon fiber unit .That wayyouwill buy 1 prop,and it can be adjusted to allow max per.of your engine.Ifyou buy a fixed pitch prop and it loads the engine to heavy,you hang it onthe wall and buy another prop,no economy their!.....Doug....."Prop Making for the Amateur" by Eric Clutton, available from the EAA forabout 7 dollars, shows how to make props including how to re-adjust thepitch after the prop has been carved.A good book for anyone's library even if you don't intend to carve yourown.Greg Cardinal________________________________________________________________________________

Original Posted By: Michael D Cuy
Greg Cardinal wrote:> >>> Doug Hunt 11/16/97 06:46pm >>>>> If you are going to use the corvair engine,i would consider using an> adjustable prop such as the "WARP DRIVE" carbon fiber unit .That way> you> will buy 1 prop,and it can be adjusted to allow max per.of your> engine.If> you buy a fixed pitch prop and it loads the engine to heavy,you hang> it on> the wall and buy another prop,no economy their!.....Doug.....>> "Prop Making for the Amateur" by Eric Clutton, available from the EAA> for> about 7 dollars, shows how to make props including how to re-adjust> the> pitch after the prop has been carved.> A good book for anyone's library even if you don't intend to carve> your> own.>> Greg CardinalGlad to see this recommendation. I am this very day gluing up blanks ofalder for a second prop for a friends subaru powered piet. (Maybe oneday I will be pursuaded to explain why this is the second prop.)Carving a prop isn't difficult, the first one will take 30-40 hours butthe second will take about 10. The above recommended book is a goodone. It will teach you how to determine lengths and pitches forparticular power, rpm, airspeed, and thrust. With the cost ofexperimental props such as one by Warp Drive or Warnke (I'd guess theycharge $400-$700) a total materials cost to build your own of about $80*is* IMHO economical.Steve E.________________________________________________________________________________