Any Innodyn news?

[cjensen]

Originally Posted by cobra

...it seems to me that the Mazda wankel/rotary design has all the advantages of the turbine with none of the problems. The Lycs do almost as well, except for smooth running and a few reliability issues.

ooohhh boy, here we go!

[gmcjetpilot]

Originally Posted by cobra

As a comparison, it seems to me that the Mazda wankel/rotary design has all the advantages of the turbine with none of the problems.

Ohoooo Boy, here we go.

EAA Sport Aviation, November 2005, "Speed Jacket"... what happens when you really change engines in a Cozy?, by Amy Laboda.

(Greg Richter, founder of Blue Mountain Avionics, discusses the engines changes he made before installing his latest power plant, a GE turbine.)

"I'd flown the Cozy with a O-235....I tried the O320.... (than) I thought I could get a Mazda...."

In the end, Richter says, his Mazda engine just wasn't practical.

"For every hour I flew, I'd have to spend an hour on the ground wrenching on it. One day I realized it's sat on the ground for nearly a year. I wasn't flying it because the engine was just too much work."

Turbines are maintenance free, a Wankel is not. Look Calling a Wankel a turbine is like calling an apple a banana. They both are in the produce section but an Apple will never be a Banana.

Any honest alternative engine advocate will readily admit that they spend lots of time on there engine, both in installation, operation and endless modification, but they will also tell you that this is the attraction of these engines, a tinker's play land. If you want to fly get a Lycoming. You want to experiment and tinker get an alternative.

With all do respect Cobra the physics and everything about a rotary engine has NOTHING to do with a turbine. If you want to think that this is a valid analogy, OK, but respectfully disagree as it is inaccurate from any standpoint you can think of. Imagine a Mazda engine scaled up to produce 50,000 lbs of thrust of a large jet engine. What would that look like? Apples and Apples.

Turbines are continuous cycle machines. A Wankel in the end is still a Suck-Squeeze-Bang-Blow engine. If you think the "rotor" in the Mazda is like an axial or centrifugal turbine I could not even start to tell you how inaccurate that analogy is. Yes the Mazda rotor "goes around", but it does not go around concentrically, it is eccentric and thus actually "translates" as well as rotates, very un-turbine like.
http://www.keveney.com/Wankel.html

Rotary with its long thin combustion chamber will always suffer efficiency issues, however I have the highest respect for late Dr. Wankel.

Merry Christmas "Big Cobra"

George

(Any one see the 2003 movie "The In-Laws", with Michael Douglas and Albert Brooks, where Douglas is a spy and involves his future in-law (played by Albert Brooks) in a spy scheme. As a cover Douglas tells a covert underworld contact that Albert is the "Big Cobra", a famous but never seen figure in the underworld as a cover. The underworld boss is "attracted" to The "Big Cobra" (the unwitting in-law), hilarious. You will have to see the move to find out where the Big Cobra gets his name from. There is few brief but good flying scenes. Sorry but sometimes I hear Cobra and think of this movie, but it is worth seeing on DVD.)

[N62XS]

The "gentleman" from BMA replaced his Mazda with a turbine, if memory serves me well. Maybe he should work on fixing his products? The only alternative I have seen in an RV that works is a Subaru from Egg and the setup was a lot of work.

[Jconard]

Quote: "As a comparison, it seems to me that the Mazda wankel/rotary design has all the advantages of the turbine with none of the problems. The Lycs do almost as well, except for smooth running and a few reliability issues."



.....bubbling noise ( sounds like a gas being drawn through water)....sudden inhaling noise.....cough, cough, wheeze, goofy laughter.


Please, Please, Please put down the pipe. Remember kids, even marijuana is a drug, and even occaisional use can seriously impair judgement and abstract reasoning. Long term use can lead to meglomania and cognitive decay.

[rvatornate]

Gmcjetpilot writes:
"Any honest alternative engine advocate will readily admit that they spend lots of time on there engine, both in installation, operation and endless modification, but they will also tell you that this is the attraction of these engines, a tinker's play land."

It always amazes me when someone who doesn't currently own one of these engines makes broad statements concerning the maintainence and workload of said engines. In the 400 plus hours I have flown behind my Egg/Sube, my work has consisted of oil changes every 25-40 hours, One set of new spark plugs, replacing the timing belt at the most recent annual, and reattaching a loose starter cable that I had improperly installed. All this from a package that took me 2.5 hours to take from crate to firewall, and a couple more hours the next day to have it run for the first time.
Yes, Jan has made a number of improvements during the 2+ years I have had my engine, and if I'd like to, I could upgrade. But I have never found myself in tinker's play land and easily fly many more hours than I do work on the engine.

Nathan Larson
N217JT RV9E
408 hours of flying....many less tinkering

[gmcjetpilot]

Originally Posted by rvatornate

It always amazes me when someone who doesn't currently own one of these engines makes broad statements concerning the maintenance and workload of said engines. Nathan Larson
N217JT RV9E 408 hours of flying....many less tinkering

First of all you don't know me or my background. I am sorry if I offended you. That was not my intent.

Second this is NOT just a wild guess on my part or the first time you have heard this no doubt. I am glad your experience is positive, but most folks attracted to the alternative engines enjoy working and tinkering, may be needlessly but for fun. I am not putting down any engine, just expressing my opinion. In the context of the discussion of Turbine reliability or smoothness, only a Turbine can achieve that level of reliability.

I grant you I have never owned an "alternative engine", but from my first hand experience, thru several friends and several airport acquittance's, who have or are doing conversions, both Subaru, Mazda and V6's, I have formed my opinion. I have read every article and builder web site I could get a hold of on "alternative engines" over the last 20 years in coming to my conclusion. The latest article in Sport Aviation and Greg Richter's quote confirms everything I have known to be correct. If you disagree, OK. May be the Egg Subaru is the least tinker intensive of the alternatives. That is cool, but my opinion is most alternative engine installations do take more work to keep airborne.

My Lycoming gets unbuttoned for oil change every 25-35 hours, so you got me beat. However I have 1000's of hours with the Lycoming. I guess I could go synthetic oil and extend the oil change interval. However I am a bit of a tinker my self, so I do know the joy of tinkering.


No matter how mad you get at me it still does not change the facts. The Subaru which you propose is more complex: Belt drive cam's, gear reduction drive, electric props, radiators and extra dependency on electricity (electronic fuel injection and ignition). More systems, more parts equals more (potential) maintenance. At least the Mazda reduces parts count.

Look stop being amazed and have a Merry Christmas and Happy Holidays.

George

[fodrv7]

I have re-read this statement by Cobra five times:
As a comparison, it seems to me that the Mazda wankel/rotary design has all the advantages of the turbine with none of the problems.

I can't see where he says anything about it's design type or that it is a turbine or that it is a contiuous combustion engine; His ONLY comment is about it's advantages v. problems.

Really George, no wonder he jumped back. All he asked for was info on Innodyn progress and he got a theory lecture, including VNE is TAS.
Now my Beechcraft Bonanza manual here quotes VNE in both CAS & IAS. Can't see TAS anywhere.

TRIM-UP-WATER-OFF-METO-SET.

[gmcjetpilot]

Originally Posted by fodrv7

I have re-read this statement by Cobra five times:
As a comparison, it seems to me that the Mazda wankel/rotary design has all the advantages of the turbine with none of the problems.

I can't see where he says anything about it's design type or that it is a turbine or that it is a continuous combustion engine; His ONLY comment is about it's advantages v. problems.

Really George, no wonder he jumped back. All he asked for was info on Innodyn progress and he got a theory lecture, including VNE is TAS.
Now my Beechcraft Bonanza manual here quotes VNE in both CAS & IAS. Can't see TAS anywhere.

TRIM-UP-WATER-OFF-METO-SET.

Well first the original poster asked the question about Innodyn. I opened it up to:

Is the RV even the right airframe for a turbine?
Will economy of scale ever allow small turbines to be economically feasible?

If you don't like my insight or technical analysis and comments I guess its too bad. What can I do I am not going to apologize to you. Several people told me they liked my input. I guess you are not one of them. I will survive.

Also I find you comments hypocritical. Cobra made this Innodyn thread into an "auto engine issue", not intended by the original post. WHERE where you to point out Cobra's error in changing the topic of the thread? I don't really care who high jacks a thread. Who are you the Thread Police?

When rvatornate made his comments, about how maintenance free his Egg Subaru is, where were you to point out that I never said ALL alternative engines are maintenance intensive?


Let me say it again a rotary engines do NOT have any of the characteristics of a turbine, EVER. I read what Cobra wrote. Reliability-no, power to weight-no, smoothness-no, Axial rotor-no. Advantages? What ones are those? high fuel consumption, high noise. Yes a rotary is cheaper than a turbine but so is a Briggs & Stratton. Cobra is entitled to his opinion. That is cool, and it is cool I disagree with his analogy; a Wankel is not a Turbine. There I said it agian.

Last "rvatornate" made his point about his experience with the Egg Subaru, which does not require him to tinker, but I never mentioned anything about Egg Subaru. However again let me say it, alternative engine installations take more tinkering in general. If you don't like that or agree that's OK with me, but please back your comments with facts and stop picking on me. At least "rvatornate" had anecdotal comments that where relevant to his point. Greg Richter says his Mazda power plant was TOO MUCH work to maintain. Kill the messenger. That is what he said not me. Ignore his comment, Ignore me please.

I am sorry your Beachcraft only mentions Vne in IAS, that is fine. If you don't believe me read the RVator article that was posted here on Vansairforce.net.

Here is the article posted and written Richard Vangrunsven, may you will believe him:http://www.vansaircraft.com/pdf/hp_limts.pdf


It is OK to disagree but for heck sakes have something to back it up with. It is true TAS is a function of Vne or flutter. Many low performance aircraft only give one Vne in IAS/CAS (for sea level). For airplanes that fly low TAS and Vne is not an issue. That is fine and no doubt the Vne has a "margin of safety" or buffer. However if you fly higher performance aircraft or sailplanes they have a Vne (IAS) vs altitude card. The higher you go the lower Vne is (IAS). The Boeing Jets I fly have an indicated airspeed indicator where Vne/Vmo is a needle ( or vertical speed tape on the PFD) that moves DOWN with altitude. I don't know what else to tell you, I guess Boeing, Van and my university professors at the school of engineering I graduated from are all wrong, and we all need to go to your Bonanza manual.


In your effort to criticize me and my post or make some unrelated comments out of context, really has shown where you are coming from. If you have something intelligent to say, than say it. Vne and jet engines are VERY relevant. If I offend you, I can't see what I said to do that, except I have an opinion and facts. May be it clashes with your perception. I am entitled to my opinion and back it up with facts or at least experience. My comments are well thought out and not intended just for you. When people do disagree and bring something to the table I learn, but your comments are a waste of time. If they are too technical just ignore them. Many people read these, who may have no experience with turbine engines or alternative engines, find the detailed info useful. You already have your mind made up.

Look what is your point? You don't like my post? OK. I get it. I am not thrilled with your's either.

Merry Christmas and Happy New Years George

[TShort]

ooohhh boy, here we go!

Boy were you right, Chad!

[fodrv7]

George,
Quite the opposite, I like your posts.
I search for them because they make me think and I end up getting out Kermode AC. Mechanics of Flight, and D. P. Davies Handling the Big Jets and searching the Net to refresh my memory of the topics you are discussing.
You really had me thinking on the Prop forum last month.
But if we are going to have an opinion on the forum then we must expect it to be challenged.
I wrote an early reply to the Innodyn post regarding your assertion that VNE was TAS, but ended up not posting it as I suspected you would get all wound up.
Surely we are trying to learn something here and if we intend to pass on ?wisdom? we need to be careful not to miss inform our fellow aviators, who might not have been around as long as you and I. So we ought to be sure our data is right??? and expect to be challenged from time to time.
I really love your bit regarding your posts, ?If they are too technical, just ignore them?.
OK Lets Get technical. I will try and avoid giving MY opinion but rather offer that of people better informed than me. And there is plenty of them.
So I rang a real old timer mate, Pat Larcey, Aeronautical Engineer and the bloke who was the Flight Test Engineer on the Handley Page Victor (what an amazing aircraft) and asked him for a refresher on VNE.
Here is what he said.
VNE is a Fixed IAS.
It is determined by a number of possible limitations; usually;
Engine overspeed
Buffet
Vibration
VNE is acceptable in most Light Aircraft until above 10,000?, due, as you point out, by encroaching on the onset of flutter at altitudes above 10,000?. But not necessarily determined by flutter.
He directed me o the CAR airworthiness regs (Australian) which state.
SUBPART G OPERATING LIMITATIONS AND INFORMATION
A26.1505 AIR-SPEED LIMITATIONS
(a) All flight speeds must be stated in terms of indicated air speed readings (IAS) in knots.
(b) The never exceed speed VNE must not exceed 0.9 VD .
NOTE: See also A26.629 (b).
(c) If VNE or VNO vary with altitude, there must be means to indicate to the pilot the appropriate limitations throughout the operating altitude range.

After a bit of Surfing I found that FAA Part 23.1545 Airspeed indicator. also makes it clear that VNE is a fixed IAS.

Regarding Ken Kreugers article, I re-read it as soon as I saw your post last week. Nowhere in the article does he say VNE is variable. Quite the opposite. The whole point of his article is that the RV VNEs work if you use the recommended power, as even if you cruise at high altitudes there isn?t enough power to cruise at speeds where flutter is an issue. He even states the flutter margin! But, and this is why he wrote the article, if you start over powering an RV the higher cruise speeds possible in your Super RV flutter might cause you some embarrassment. The table for the PIPISTREL SINUS isn?t his and is someone?s personal way to ensure he doesn?t risk flutter by ?Artificially? reducing the VNE. Which we all now know, if we accept the FAA and CASA definition is a fixed IAS.

I do fly high performance sailplanes, by the way, and specifically joined a particular club because they have wave over the field enabling flights to FL270. My last aircraft was the B777 (they took it away as they said I was too old to fly it anymore.) but despite what they said I do still remember that the VMO was a fixed 330KT IAS until limited by MMO. I seem to recall that the B747-400 did have two different VMOs I think depending on AUW. However, everything else I flew DC-9, A320/A330/A340 and B737 200 and 300 all had fixed IAS VMOs. And yes I do remember the Barber pole coming down and obscuring the ASI on the DC-9, but it?s all a bit vague as I spent the last 25 years flying ?Glass?.
George, I do apologise for offending you in taking you to task on VNE. My intent is not to offend but rather ensure that information on this forum is accurate and provides information that will assist in the safe operation of our fellow Rvs flyers.
If I didn?t live 8000nm away I would come over with a couple of beers for a Christmas drink.
Have a great Christmas and a great New Years Eve too .
Pete.