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Round the world journey planning

HighSchoolBuilders

Well Known Member
Hi All,

I am in the process of planning a round the world trip with my RV-8. Unfortunately, I didn't have any luck getting it fly again in Hong Kong and was forced to ship her to Brisbane, Australia for my phase 1 flight test.

May I ask the guys with an IO-360 fixed pitch prop (I have a Catto three blade), what is the most fuel economic speed and fuel burn rate? I understand all planes are built different, just for preliminary planning purpose, and I can fine tune that when I begin my flight testing.

We are building a set of wing tip tanks plus a fuselage tank to get enough range to go across the pacific, from Hilo to mainland U.S. Depend on the fuel burn and cruise speed, I can then decide how big the ferry tank needs to be.

Thanks all!
Hank
 
Some numbers

I am sure you will get specific input on the RV-8 and the IO-360 and LOP etc. but for some comparison on my -7 with 0-360 and the new 3 blade Catto, at economy cruise (around 55% power) I get about 165 MPH and burn around 7.8 GPH running slightly ROP. Data is from Dynon D100/120.
Figs
 
It will be around 90-100 KIAS depending on weight, altitude and head wind, approximately the same as your best glide speed and the type of prop won't make much difference to that speed. You may find that frustratingly slow and choose something nearer Carson's speed for not much fuel penalty.

Electronic ignition, balanced injectors and careful LOP mixture will make much more of a difference than flying at max range speed.

Altitude doesn't have much effect on best range distance, although the speed for that range will be lower at low altitude.

I could achieve about 120 KIAS at 50% power and 5.7 gph and 1700 lb mass with everything fine tuned. That was with a Hartzell prop set WOT and the lowest RPM to achieve that power.
 
RV-8A economical LOP cruise; 168 knots, 7.5 - 7.8 gph, 23.5" (or WOT), 2350 - 2400 RPM, 8K to 12K altitude. If can go slower and can get a lower fuel burn but perhaps not that big of a gain in miles per gallon.

180hp IO-360, dual pMags, balanced injectors and Hartzell BA CS prop.

If you stay with the FP prop plan on a significantly higher RPM and fuel burn.

Carl
 
Catto

I have a Catto fixed pitch 3 blades prop, dual LSE ignition. The prop should be pitched for cruise on a IO-360.

Sounds like the number does varies quite a bit with different setup.
 
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