Jarret,
Yes, that would be me. Thanks for the kind words regarding the rotary. Yes, I'm close to first flight. But installing an alternate engine isn't for the faint of heart. But then neither is building a Lancair.
As for the rotary, I love this engine. It produces 300 hp with only four moving parts, all of which move in a circular motion, so it is very smooth. Short block weight is only 296#. Pistons (rotors) are cast iron, so no need to worry about damaging them and the crank is almost indestructible. There are no exhaust or intake valves, so no worries about running too lean. If there is a failure, they have a reputation for continuing to run until shut down, then they may not start again, but they will run until turned off.
The downside is that they are water cooled (which may be viewed as a plus). But it does require much thought and planning for a successful cooling system. Mazda no longer produces the 20B engine, although most of the 2-rotor parts will interchange with the 3-rotor. And I hear that there is a company that produces the 3-rotor crankshaft and one unique center-housing. There are a few off-the-shelf parts available (EFI/Ignition Controller, psru) but you'll have to fabricate your own intake manifold, exhaust manifold, and motor mount. But there are people working on these items.
Also, it requries a gear reduction unit. These are available from Real World Solutions. But they don't have an integral prop governor, so you'll either have to use a fixed pitch prop, or an electric such as the M/T. You can purchase a psru from Mistral which does incorporate a prop governor. Or, you could just purchase an entire certified rotary engine from them.
One other plus is the ability (actually a preference) to burn mogas. The lead in 100LL is a negative as it shortens the spark plug life considerably and also causes problems with the A/F sensor. So, I plan on burning mogas or 87UL whenever possible. Speaking of spark plugs, the rotary has two plugs per cylinder (rotor) and it can be run on either in sort of a limp-home mode, but normally you run it on both. Same for fuel injectors (two per cylinder and in an emergency you can run on either the primaries or secondaries).
Since this setup is electronically dependent, it runs dual alternators and dual batteries, per Aero-Electric Z-14 design.
As a side note, I run two efi fuel pumps with a fail-over relay. This design is similar to what was just mentioned today on this list. You can see a schematic, along with p/n's on the Eggenfellner Subaru site. I copied their system. It will kick on the backup fuel pump if the fuel pressure drops below sensor pressure. My sensor is set for 25psi. It also lights an LED telling me that the backup pump is running. I can re-arm it once the pressure comes back up.
This is probably more information that you cared to hear. Hopefully, I'll be joining you at the fly-ins in the near future. Yes, I'll have the cowl off.
Mark S.
LNCE
On 6/6/07, H & J Johnson <hjjohnson@sasktel.net> wrote:
I don't know if you've concidered this but, if it was me building an ES or a IV and I
was looking for a engine for it, I'd be leaning towards a 20B rotary. It's basically the
same engine as a 13B [which came in all of the 80's & 90's Rx-7's] with an extra
rotor, making it a three rotor. I would think 300hp should be no problem. There
are Rv's flying w/ 2 rotors making over 200hp, adding the third rotor and the
power is basically scaled linearly, making it around 300hp. They are light and super
compact, and there a fair amount of 'off the shelf' item's one can buy to use in
your FWF build, and more coming out all the time. There is also someone
currently on the list who has a ES with a 20B and is very close to flying.
I'll let him pipe up, if he so chooses.
Jarrett Johnson
235/320 55%
>
> I wrote:
> >>If I needed a big 6-cylinder engine for my aircraft, I would not
> choose a fuel-injected Continental.<<
>
> George Braly asks:
> > So which large bore six cylinder engine would you select - - and why
> > do you think it is "better" ?
>
>
> I have not been shopping for a 6-cylinder engine. I have been reading
> what Lancair builders have to say about theirs. For reasons that have
> been thoroughly discussed already, I am convinced that the Continental
> fuel-injection system is a bad design. If I were shopping for an
> enginefor my Legacy / LIV / LIVP, I would consider...
>
> a) Continental (T)IO-550 with a separate fuel-pressure regulation
> system so that flawed system only has to deal with one fuel
> pressure. Better because I can leave the fuel pump running and
> not have the
> engine quit.
>
> b) Continental xO-550 (where x is some fuel delivery system other
> than the stock Continental). Better because the fuel mixture
> is determined by the fuel need (e.g. MAP and RPM).
>
> c) Lycoming IO-540, which has a fuel injection system that is more
> closely based on right parameters.
> Better because it is readily available, fits the space, and has
> a fuel injection system that doesn't suck as badly.
>
> d) Some other ~300 HP engine... possibly a Subaru H-6 with a
> turbo or supercharger. That would be an adaptation of the
> Eggenfellner Subaru package for the RV-10. Better because
> it has much better fuel flow control, is smoother, and is
> less expensive, but is electricity dependent and heavy.
>
> e) Maybe by the time I build a bigger Lancair, there will be a
> good firewall-forward package based on the Chevy LS series
> aluminum V8 engines. Better? I don't know.
>
> If I were building an aircraft that needed an engine in this range,
> those are the choices I would consider initially. With further
> research something else might appear better.
>
> George - I applaud all that you have done to improve fuel economy,
> the fuel distribution in aircraft engines, and to improve the state
> of understanding among pilots and mechanics. PRISM is another step
> in the right direction. Perhaps GAMI could profitably fit a better
> injection system to a Continental engine and make it a better engine.
>
>
>
>
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