flyrotary@lancaironline.net Mailing List Archive

Dwayne,

Ed Anderson could put this better than I, but the large flat surface of the rotor cools more quickly than a piston crown, this reduced heat doesn't help with atomization for the most effective burn of fuel. This coupled with the squish areas at the ends of the rotor extinguish the flame front resulting in unburned fuel remaining in the combustion area. The RX7 13B engine spat that out the PP exhaust - not good for EPA standards. The RX8 engine pushed the fuel into the next combustion event, which helped with EPA standards. The 16X engine has a narrower rotor, that means less surface area ( more heat -better combustion) which is coupled with a larger displacement - more power, better fuel economy better environmentally.

Hope that helps and I agree with all that you say - especially the last sentence.

George ( down under)

Excellent points on the 16X. I don't know enough about rotary engines to know what "bad" will happen by redesigning the rotor and all the little tweaks. All Dave said about the 16X is that Mazda is "dancing with the EPA." The implication was that they would do things to the engine that would make it less than ideal for an aviation application simply to meet EPA mandates. I guess we wait and see.

Regarding the reasons I'm putting an auto conversion in my plane:

1) I want to know my engine inside and out and have as much faith in it as I have in the rest of the plane that I build.

2) It's cold in the winter up here and I like heat in the cabin.

3) It's cold in the winter up here and I don't like shock cooling.

4) It's cold in the winter up here and I really don't like pre-heating.

5) I don't want to worry about what's going to happen to 100LL next year.

6) The acquisition cost can be spread out over time.

7) Maintenance costs are lower.

and most importantly.... just so I can hear "I'd feel a lot safer flying behind a good old reliable airplane engine" about 100,000 times :)

Dwayne

From: Ed Anderson <eanderson@carolina.rr.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Mon, August 2, 2010 6:39:07 PM
Subject: [FlyRotary] Re: Bad rotary week

I put 2 cycle oil into my gasoline (like most rotary fliers) to eliminate the need for the rotary oil dispenser and having it consume crankcase oil. I use approx 3/4 - 1 oz per gallon so for my 38 gallon tanks I would use 38 oz of oil for a 4 - 5 hour flight - so right around 1 quart. However, I have never needed to refill engine oil in my 500 hours of flying which same can not be said for aircraft engines.

I didn't hear Dave's talk but disagree with comments regarding the 16X - I personally believe it is better suited for aircraft use than the current rotary engines for these reasons.

1. The torque has been double at all rpms - that means you can swing a much larger prop (or multiblade prop) giving greater performance for take off and climb

2. The displacement has been increased by 300 cc which is going to improve power

3. The size of the rotor has been increased in diameter and narrowed which should improve fuel efficiency.

4. The side housing will be all aluminum rather than cast iron saving in weight.

5. There are others enhancements, but I think those are the ones of most interest to aviators.

my calculations indicates it should have no problem producing 220 HP (possible more) at our typical aviation rpms. - so I am drooling for the 16X, was hoping they would bring it out this year, but appears they will not.

But, deciding to put a rotary (or any alternative engine) in your aircraft is a big decision. So make certain you undertake the effort for the reasons right for you.

good luck

Ed

From: Dwayne Parkinson

Sent: Monday, August 02, 2010 5:43 PM

To: Rotary motors in aircraft

Subject: [FlyRotary] Bad rotary week

For anyone hoping that a 16X would show up any time soon: not ... gonna ... happen. No RX7 and the RX8 is still powered by the Renesis for 2011.

http://www.mazdausamedia.com/content/2011-mazda-vehicles-glance

As if that's not bad enough, when I was at Oshkosh I took in David Atkins rotary seminar. I came away pretty depressed thinking that I probably won't put a rotary engine in my airplane. Is everyone else really using 1 quart of oil every 5 hours? He also didn't have much good to say about the Renesis in an aviation application which leads me to conclude that the 16X will fare even worse in aviation applications as it is tweaked to meet higher EPA requirements and produce more low end torque.

Is anyone but Tracy using a Renesis? I'd really like to know what HP you're getting, what the fuel burn is and how it's holding up.

Thanks,

Dwayne

P.S. I couldn't find any rotary planes on the field at Oshkosh. Perhaps they sank into the mud.

Ed Anderson
Rv-6A N494BW Rotary Powered
http://www.andersonee.com
http://www.eicommander.com
http://www.dmack.net/mazda/index.html
http://www.flyrotary.com