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Old 18th Sep 2013, 05:14
  #15 (permalink)  
Join Date: Jun 2001
Location: Albany, West Australia
Age: 79
Posts: 482
If you can do without the aeros buzz, then the RV-9/9A wing is the more efficient at higher altitudes than the 7 series.

If you are going to build your own wings - then you can build in a set of auxiliary tanks outboard of the mains - but not way out at the tips like the Johansen type. VH-JSP,(a 9A, currently hangared at JT), sports a set of 35L aux tanks which are plumbed into the main fuel selector via a 2nd fuel selector for R/L aux. Using these @ 30 mins each creates next to nil wing out of balance. In round figures - another 120-150 mins endurance.

Fuel injection and electronic injection make a very good combo with the 360 engine - but you are then into avgas only. Probably a set of GAMIjets will improve this again. Even without them - my IO-360 in a 9A will give me 140 KTAS @ 27LPH ROP, and 23LPH @ LOP. And that's with an 87 inch pitch fixed Sensenich prop.

For the money, I think you can actually get more efficiency out of fixed pitch props pitched well to suit your long distance cruise intention. Save $8k, and some weight too.

Now if it comes to not using avgas, perhaps you could still run the higher compression FI/EI engines using some form of anti-knock additive to replace the avgas lead?? Something which might make these engine useful into the future?

happy days,
poteroo is offline