| Ted,
If you are of the belief that Lycoming or Continental are "safe" choices, may I direct you to the FAA accident database? It is full of evidence to the contrary.
Thanks for mentioning the Fly Rotary group ( www.flyrotary.com) of which I have participated in since the mid 90's. A couple of other good rotary sites are www.rotaryeng.net and www.rotaryaviation.com. There are many flying examples of the rotary engine being a viable alternative engine. While it is definitely not a plug-n-play solution and nor is it for everyone, it has proven to be a reliable aircraft powerplant. But, as they say, the devil's in the details. As with the Lycoming or Continental options, I wouldn't call the rotary a totally "safe" choice either. A broken oil line can ruin your day as quickly as a broken crankshaft. If you address the peripheral systems, the engine itself is extremely robust. (My 350hp peripheral-ported 3-rotor engine has only 4 moving parts, all of which spin rather than stop and start, but that's a topic for another posting.) The rotary has shown to be more than capable of producing very high power in racing applications. In the Mazda series they typically run the engines for one or two seasons without overhaul. The rotary is a very tough little engine!
Is the Lycoming engine "safer"? Maybe, maybe not. But if "safe" is the target to which we aim, then we should all stay on the ground.
Mark Lancair ES, n/a 3-rotor
On Sun, May 29, 2011 at 7:32 AM, <tednoel@cfl.rr.com> wrote:
While I am confident the Eagle V8 will do well, based on the designer and many bits of the internals, it has proven very expensive and time-consuming. Check in on the FlyRotary email list (Marv runs it). There are rotaries of the appropriate power flying with good records. Many of the headaches have already had their aspirin taken. Unless you are a bit of a masochist (which I didn't think I was), unfortunately the 1930's boat anchors remain the "safe" choice.
Ted Noel
---- Rod Pharis <rpharis@verizon.net> wrote:
> Many years back an apparently qualified and well healed small company began
> development of a 572 cid Chevy big-block engine converted for aircraft
> applications, including a less expensive replacement for certain turboprop
> power-plants. They spent piles of money and many years of work, including a
> special speed reduction unit. In the end, not a single original part was
> retained, including the spark plugs. The company was in poor financial
> health at that point, and I believe another company bought that company and
> the rights, and they apparently did no better with the project even though
> they inherited many lessons learned from the first owners. As far as I can
> tell, the project was abandoned. A single guy would have little chance at
> success with a one-off attempt. Don't even think about it!!!!!!!!!!! Even
> a small modification to an existing successful airplane engine would likely
> take deep pockets to be successful.
>
> Rod Pharis
>
> From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Gary
> Casey
> Sent: Tuesday, May 24, 2011 10:23 AM
> To: lml@lancaironline.net
> Subject: [LML] Re: L-IV Choice of Engine
>
> I have read with interest many of the posts on this subject. I too, had
> considered an automotive engine to the point I acquired the engine and
> designed most of the systems. I was convinced (and still am) that an
> automotive V8 run inverted, turbocharged with direct drive to the prop could
> do an effective job. But....
> Brent makes many good points and I agree with them, but engines are
> inanimate objects and don't respond to the intent of the designers - they
> only respond to the details of the design itself. So what makes the
> liquid-cooled automotive engine inappropriate for an aircraft application?
> Liquid cooling helps, as a smaller bore with cooler surface temperatures
> allow a higher compression ratio, but the slower-running large displacement
> aircraft engine has lower friction, negating the benefit of the higher
> compression ratio. An efficient radiator can cool with less pressure drop,
> but it requires about twice the air flow of an air-cooled engine. The
> liquid-cooled engine can be more compact, reducing the frontal area, but the
> frontal area of a side-by-side seating aircraft is usually determined by the
> cabin, not the engine. The list goes on.
>
> Is the aircraft engine old-fashioned? The configuration has been around for
> a long, long time, but that doesn't have much to do with the effectiveness
> of the engine. The engineers at Lycoming and Continental have cherry-picked
> the technologies developed by others that apply to aircraft engines, and
> developed some of their own. Bottom line? I'm happy with the 50-year-old
> Lycoming in my ES. And while I usually wish for a turbocharger when getting
> out of my 3800 ft, 7000 ft elevation runway, once in the air the fuel
> efficiency of the high-compression, naturally-aspirated engine is nice.
>
> Gary Casey
> ES #157, naturally aspirated Lyc IO-540
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