I think a secondhand Sonex is right for me, Seeking Opinions

[daleandee]

Will give you cheaper running costs, so saving, (balancing out the initial cost) over time.

The AeroVee burns 4GPH and for $2500 worth of parts you can do a major overhaul.

If you like tinkering & maintenance the Aerovee is cheap to fix in most cases as they are simple engines. I'll make the same claim for the Corvair also. Rebuilds of Corvair flight engines are said to be quite economical and parts are abundant (GM built nearly two million Corvairs). The flight version of these engines are very different from their humble auto beginnings and with viton seals they do not leak oil and they run very cool in these airframes.

My condition inspection is due and usually for the engine that entails changing oil & filter, cleaning the K&N airfilter, compression test, cleaning or replacing plugs and an overall inspection. I get a sample for oil analysis and thus far they have all come back excellent. I did replace the alternator belt last year.

I can't claim the great fuel burn that Bryan gets with the Aerovee because I burn ~5.6 GPH unless I want to pull it back and cruise slow. I'm not against Rotax but I flew 2 strokes (Rotax) and to me the high RPM of the two strokes & even the 912s don't sound airplaney to me. Personal choice but a slower four stroke is what my ears like to hear when a plane comes over ... unless it's a radial!

Dale
3.0 Corvair/Tailwheel

[Kai]

[/quote]
The Rotax is awesome. But cheaper running costs than what? And does that include reserve for overhaul? The AeroVee burns 4GPH and for $2500 worth of parts you can do a major overhaul.[/quote]

Bryan,

I might be totally off the mark, but I believe the point Skippy was trying to make is that with the Rotax chances are you don´t have to spend $2500 for an overhaul (every 500 hrs?). The present R912 tbo is 2000 hrs, and more often than not they keep on running happily on condition for years after that. Still, for many leisure fliers neither the fuel burn nor the overhaul costs are the the real show stopper: but we take exception to spending half a (flying) lifetime repairing and replacing parts on more or less bona fide aircraft engines- would´nt it be a nice alternative to spend that time in the air? So in comes the R900-series (truly, they have had their issues in the past as well). I understand that a properly built Corvair is now also on its way to reach the same status. Then you have (the still unproven?) Jab gen4 series. I´m sure there may be more. So in the end it might come down to making up ones mind: do you like working on the engine, or do you like flying?

[Skippydiesel]

Will give you cheaper running costs, so saving, (balancing out the initial cost) over time.

The Rotax is awesome. But cheaper running costs than what? And does that include reserve for overhaul? The AeroVee burns 4GPH and for $2500 worth of parts you can do a major overhaul.

Lets see -

Rotax 912ULS (100 hp) will burn 14L/hr ULP (95 RON $1.90 /L, 98 RON 2.04/L) at 5000 rpm, for an easy 130 knots indicated (137 knots true) at 3000ft.
Rotax require an oil change, 3L/ $19 AU/L, every 100 hrs.
There is a complete rubber change at 5 years (for me thats about $600- $700AU).
Spark plugs are good for 200 hrs - around $85 AU /set.
Nearly forgot - there is a 1200hr gearbox/clutch inspection, which will likly require some new parts - don't have an AU price, sorry!
Most Rotax will make 2000 hrs and some get well over 3000 hrs, without any major surgery (ie replacing costly parts, extended down time and if you can't fix yourself, expensive labour).

You do the maths