Maury Wrote:

The FAA is partially to blame for this. If any change at all is made in

the

aircraft engine, and that includes material change, the engine must be
re certified. Naturally this discourages development.

  There are times where I'm getting philosophical over a pint, and the whole
state of the GA industry really starts getting me down...

If the automotive companies developed an aircraft
piston engine from scratch there would be no doubt in my mind that
it would look very much like an air cooled aircraft engine and be largely
made from the same materials.

  That's interesting, and a question I was always curious about. Then again,
I suppose the Orenda is proof positive of that. BTW, does anyone know when
Orenda stopped being a part of Hawker and was taken over by Magellen?

materials for the ferrous parts.  I don't think liquid cooling is
worth the trouble and extra installation cost and weight.

  Wouldn't that depend on the setting? For most uses I would agree, but in
the (former) edge-cases that seem to becoming more popular I'm not sure if
that's true. In the skydiving world it seems like a water-cooled/charged
like the Orenda is a dream come true - those planes climb at 100% to 10-15k,
then do a power-off high speed dive to the ground for the next load. And
no-one in Canada flies enough jumpers to afford a turbine...

Maury

That last bit is real simple and cheap to fix Maury. Just close off the air intakes with
shutters and cowl flaps on the way down like the Russians do with their radials. 
No need for a $120,000 US dollar 1500 hour TBO  Orenda V8 less installation cost. 
If they are not turbo aircraft engines then they are not 100% all the way to 10-15K.

BTW a Mazda based four rotor would beat the Orenda in power to weight ratio 
hands down. Cast iron end housings and all. Bare block weight would be around 
400 pounds. Add 150 pounds for turbo and planetary redrive and you are looking at 
an easy 600 HP. The Orenda V8 firewall forward is reputed to be over 1000 pounds.
Here is only a three rotor on the RB dyno generating 900 HP with at least 200
durability hours so far. Not all at full power.

Paul Lamar
 
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