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Innodyn Turbine ???

knuther

Member
http://www.innodyn.com/aviation/products.html


What are your thoughts on a turbine powered Rv-4 / Rv-8 ?? From what it looks like and from what they are saying on their site it is going to burn comparable fuel GPH for similar HP. They said they dont want to quote anything yet becuase they are hooking up better test equipment to the aircraft to find closer mesurments. But what would be the performance of somthing of different as this... i would assume it would probally be a slightly longer takeoff and overall a little trickier with the speed based on prop pitch alone.


but the mantience alone looks very nice plus i assume you could take this engine to pretty high altitudes. and they are going to have firewall forward kits for the RV's and it sounds very reasonable price wise for what you recieve anyhow.


What is everyone's thoughts on it.
 
if they had some extraordinary numbers, they'd be all over the place.. in bold text... (instead of not wanting to publish 'em.. wonder why..?) BSFC equal to that of a Lyc would qualify as "extraordinary."

do a search on yahoo groups (try vansairforce group), as there has been a lot of electronic ink spent discussing this particular set up.
 
i did right after i posted this . I found a few sounded that pretty much everyone was in the boat that they didnt want to be the first one to fly it . Others said it would drink to much fuel but they were flying older less effic turbines.

I guess i am in the camp that new = good. I did shoot off a few emails to Innodyn about top end/ low end/ performance at different alt and such .. i havent heard much back.

But then again i probally have a year before i buy a kit. that then a few years invested in the building process. should give me enoughf time to see if the company makes it or burns up showing it was a bad product. I guess if it was everything they said it is it will do very well.
 
knuther said:
But then again i probally have a year before i buy a kit. that then a few years invested in the building process. should give me enoughf time to see if the company makes it or burns up showing it was a bad product. I guess if it was everything they said it is it will do very well.

You're new to this engine stuff, aren'tcha? :D

You have to learn how to interpret what these new engine inventors say and where they're at in their "timeline" to production.

A. If they have a nice website and, and have a prototype built, that means that they are never going to build that engine for production. The prototype was just to gather up a bunch of investor's money before relocating to Aruba.

B. If "A" but the company principals didn't move to Aruba, plus they have an engine running, it might fly within 18 years.

C. If "B" plus they have one flying, and they offer a "production position" that will put you in line for one some time down the road, and you sign up for a "production position", then you are more optimistic than they are. Give it about 12 more years.

D. If "C" plus they are accepting downpayments even though they have no production schedule, and you send them money, then you may have just proven that your judgement is highly questionable and you might want to rethink your building something from which you intend to hang your *** at altitude.

E. If "D", plus they have a couple of engines flying, you are almost good-to-go except that it will take 6 more years before enough FWF engineering and parts availability makes the engine viable. That is, if the company can stay in business until then. Add 3 more years waiting if you don't want to pay big $$$ for the priviledge of being one of the first "test" pilots for their engine.

That's sort of the timeline for really cool "new" engines such as the TCM-GAP engine (dead... gone... shelved), Zoche (I think that's German for "dream on"), Dyna-Cam (lot's of reasons why it's taking so long.. ad infinitum).
Even the Deltahawk which the company touts as being "almost" ready for production will probably be several years away because there is absolutely no FWF support considered by the company itself, and they won't even say who "all" the other people are who are supposedly working on FWF issues.

So if you think you'll be flying within 8 to 10 years, here's the plan; get a Lycoming engine, fly the 2200 hours until it's time to chuck it (probably about 10+ years), and THEN see who has a "ready to go" super duper, highly tested with lot's of accumulated hours engine that's powered by Dilithium crystals, and go for it!

Vern
RV7-A
 
Innodyne

I emailed them a few months ago for performance figures...they never emailed me back. I suspect this is because the performance figures are not the kind of thing you want to give out at this point. There are alot of heated discussions about this thing on a yahoo news group...the more I read the more I feel the need to bolt on "old technology" and just fly...yup it might be boring (to have old technology) but not nearly as boring as sitting on the ground! :D

Oh yeah and about that GAP engine...it ticks me off that millions of $$$ in tax money was spent on something that no one got a benefit of. The least they could have done was published all the research so some other company could have given it a go :confused:
 
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Yup your right new to avaiation. Not new to the story of any aviation just new to GA. To bad that is the case i guess i never knew the whole story.. maybe thats why the 2 main brands are still around becuase they keep makeing them, people keep buying them, and they are pretty reliable
 
knuther said:
http://www.innodyn.com/aviation/products.html


What are your thoughts on a turbine powered Rv-4 / Rv-8 ??
What is everyone's thoughts on it.

When they were ATP, they were talking somewhere less then 15 gph for a 200 hp engine. This is a little worse than an 0-540 (225 hp at .75%), but not bad when you measure it in cash flow. It get's better when overhaul costs are considered. The 5000 hour TBO seems about right.

This fuel flow really isn't that out of line. The Walter 602 guys claim about 20 gal/hour at FL 25, this should be around 320 shp, assuming the same sfc, you'd end up around 12 gal/hour at 200. (sigma=.44, 710 shp at SL)

In other words, these guys really aren't all that "pie in the sky." From what I understand this it is based on the old Solar T-62 APU (originally developed as a small helo engine). Not necessarily a bad thing if done right.

At this point, I don't think it is fair to lump them in with Zoche, Dyna Cam or Bede (as others have). Bede always made extravagant claims backed by terrible business decisions. These guys are offering a reasonable numbers, and holding those close to the chest as this point could be considered prudent just as easily as evasive. They seem to have gotten the business house set up before taking orders (unlike Bede). Zoche pumped the aviation media for attention for decades without ever producing flight hardware, these guys were flying hardware before most people even knew about them. And unlike Dyna-Cam, they aren't doing anything different or new, just updating a proven design.

I like their chances. BTW, in 1973 who would have thought there would be more RV's build in a year then Cessna 172? Aviation is a grave yard of big dreams and bad ideas, however there are successes also.
 
You've probably seen this, but if not, it's a good read. Apparently it is simply a T-62 updated for modern machining and electronics. They say the cost of producing it is 1/10th of what it cost in the 1960s, and the cost of the fuel controler was 1/3 of the original cost. Basically, this is made possible only through the miricle of low cost integrated ciricuits.

http://www.eaa.org/benefits/sportaviation/RV-4T304.pdf

They've updated their site, seems like there wasn't much useful out of the DARPA tests. However, they did get a slight improvement over the standard FC, but the tests were limited to a 110shp genset.
 
I received this via e-mail today:

Thanks for your Email on the RV4. We are very far behind in response to our emails, sorry.

We are currently providing the firewall forwards for the RV 4. Our prototype needs a new design and that is forthcoming. We will be offering an installation manual in about 4 weeks at $100.00 which will save a lot of time.

Best wishes
Charlie Sullivan

Director of BuisinessDevelopment
 
"Our prototype needs a new design and that is forthcoming."

I love it! But I'm afraid that what they're really saying is: "We've discovered a problem in the design which will require that we have to start from scratch so check back in another 10 years of so. Thank you for your interest, and don't forget to register for a production position."

:D
 
If you read the PDF on page 1 of this post you read that they hit a limit when they tried to make the turbine exhaust dump out the bottom without the large ugly dump tube most turbines use for their exhaust tube.


what they said was when they hit 160 they were getting back pressure in later movies i seen with there example i see a larger tube down the front .. I am wondering if what they hit was a nice looking setup but perhaps not large enough intakes now. You would think with increase hp less weight and less front area in the cowl they could get pretty good speed out of it .


I bet they hit like 200 and ran into a road block.

5 more years they will have it worked out :)
 
Being new to GA and homebuilding, but having 3000hrs in military high performance turbo prop complex aircraft... and a very close friend who designs, builds and sells exerperiemental turbines for the DoD... I'd like to share a few thoughts...

1. small scale jet turbines have efficency issues due to their size related to the tollerances they can be manufactured too... a few thousands gap around a turbine that is 3' in diameter vs. a turbine with the same manufacturing tollerance at 1' in diameter is huge a huge loss of effeciency...

2. turbines are more reliable in general than recipricating engines.

3. at low altitudes, low airspeeds (think ram air benefits) and low power settings a turbines efficiency will be lower than high & fast. This is due inpart to the fact that at low altitudes turbines blead off a significant portion of the air they compress and as they climb this blead air is reduced and hence more of the work going to compress air goes to also burn that air...

the guys who started Innodyne were reported to be experienced machinists who understand all this... I read about them years ago in kit planes and the EAA magazine. They were having back pressure issues back then with exhaust stack design...

But it seemed to me since they made there money with their machine shop and weren't in a hurry they had a chance to develope a suitable turbine. They also seemed to have a good grasp on tightening those manufacturing tollerances that give the motor a chance at better efficeincy.

Now wether -any- turbine will work well on a Van's is another matter. Fixed gear doesn't bode will with 200-300 kt aircraft... and while a Vans has very impressive numbers I don't know that any of them are 300kt aircraft (not considering the 'rocket' derivatives).where a turbine really sets itself appart.


I'm in a personal conumdrum... I've got lots of time flying fast airplanes... tubro props, and I want one of my own... I'm a rarity in the GA market who doesn't have the cash for a Pilatus or a BDM... nor even a Lancair Evolution...

So I'm thinking about a Vans/rocket with a small turbine in the nose, because thats what I'm used to flying and understanding....
 
I'm in a personal conumdrum... I've got lots of time flying fast airplanes... tubro props, and I want one of my own... I'm a rarity in the GA market who doesn't have the cash for a Pilatus or a BDM... nor even a Lancair Evolution...

So I'm thinking about a Vans/rocket with a small turbine in the nose, because thats what I'm used to flying and understanding....
Two questions:

1. Do you want a plane to fly, or a plane to tinker with?

2. Do you fully understand the implications of being a powerplant test pilot? Consider all the possible failure modes that an experimental powerplant/prop has, and ask yourself whether you are prepared to potentially deal with each of them.
 
A few thoughts for you...

Being new to GA and homebuilding, but having 3000hrs in military high performance turbo prop complex aircraft... and a very close friend who designs, builds and sells exerperiemental turbines for the DoD... I'd like to share a few thoughts...

1. small scale jet turbines have efficency issues due to their size related to the tollerances they can be manufactured too... a few thousands gap around a turbine that is 3' in diameter vs. a turbine with the same manufacturing tollerance at 1' in diameter is huge a huge loss of effeciency...

That and a few other thermodynamic problems scaling the design down in size.

2. turbines are more reliable in general than recipricating engines.

Could be, but no one has ever built, run, or tested the engine you are looking for.

3. at low altitudes, low airspeeds (think ram air benefits) and low power settings a turbines efficiency will be lower than high & fast. This is due inpart to the fact that at low altitudes turbines blead off a significant portion of the air they compress and as they climb this blead air is reduced and hence more of the work going to compress air goes to also burn that air...

the guys who started Innodyne were reported to be experienced machinists who understand all this... I read about them years ago in kit planes and the EAA magazine. They were having back pressure issues back then with exhaust stack design...

I think most of the "backpressure" was coming from their bankers or investors. You will note that the last post before yours on this subject was almost exactly three years ago. Not a lot of movement.

But it seemed to me since they made there money with their machine shop and weren't in a hurry they had a chance to develope a suitable turbine. They also seemed to have a good grasp on tightening those manufacturing tollerances that give the motor a chance at better efficeincy.

The efficiency issues connected with the production process are simple compared to the fuel metering and prop control issues. Both of these could be cured but the cost would be huge and the potential market is too small to make it viable.

Now wether -any- turbine will work well on a Van's is another matter. Fixed gear doesn't bode will with 200-300 kt aircraft... and while a Vans has very impressive numbers I don't know that any of them are 300kt aircraft (not considering the 'rocket' derivatives).where a turbine really sets itself appart.

I tend to agree, but Innodyn was marketing their prototype in a Super Cub. Not exactly a "high and fast" airplane. I's not from Van's but you need to look at a Legend (http://www.legendaircraft.net) a little more realistic way to have a turbine homebuilt since it uses a production engine.


I'm in a personal conumdrum... I've got lots of time flying fast airplanes... tubro props, and I want one of my own... I'm a rarity in the GA market who doesn't have the cash for a Pilatus or a BDM... nor even a Lancair Evolution...

So I'm thinking about a Vans/rocket with a small turbine in the nose, because thats what I'm used to flying and understanding....

Me too, 10,000 hours behind turboprops, especially ones that other people are paying for was good fun but when it comes to paying the bills yourself and wanting to get it off the ground this century, you might want to look into something proven to power your project.

You might want to do a search on Innodyn, there are hundreds of posts.

John Clark ATP, CFI
RV8 N18U "Sunshine"
KSBA
 
I fly one too

So I'm thinking about a Vans/rocket with a small turbine in the nose, because thats what I'm used to flying and understanding....

...but I have a trusty old Lyc on my -6A. I have a super dependable PT-6-15 in my workweek airplane and I love it. Would I want one in my RVxxx? No way. For starters, a good used one is over $110,000..new, probably $300,000 now....secondly, it'd be very difficult to not be flying over redline most times...and third, where are you gonna store all the extra needed fuel? I'm very content doing 198 TAS like yesterday, burning 9+ something gallons an hour:D

Welcome,
 
and third, where are you gonna store all the extra needed fuel?

A good example of this is the turbine legend. Great performing airplane, sexy looking and well designed. It has the same exact wing as my radial rocket and the max fuel you can squeeze into the wing using every nook and cranny is about 110 gallons and then you have to be really careful loading the plane because of CG.

Given their fuel burn on the ground and in the air you need to be taxiing up to the pump for a refill 2 hrs after you START the engine.

Really limits the utility of the plane especially relative to travel and IFR in particular.

Even if Innodyn solve all the technical issues in an RV you are probably gonna have less than 2 hrs of run time before tanks are dry.

Thats too bad and RV8 with a turbine would be just way cool.
 
Thanks for your Email on the RV4. We are very far behind in response to our emails, sorry.

We are currently providing the firewall forwards for the RV 4. Our prototype needs a new design and that is forthcoming. We will be offering an installation manual in about 4 weeks at $100.00 which will save a lot of time.

Best wishes
Charlie Sullivan

Director of BuisinessDevelopment

Back several years when I first got involved with homebuilts and knew absolutely nothing about anything I got all excited about an RV 8 or F1 with an Innodyn Turbine. I am embarrased to say I called and talked to "Charlie" at length and bought one of his manuals. I came close to purchasing an RV 8 and a prototype engine, thank god I didn't. With the manual came a place in the delivery schedule and a discount for having bought the manual. The manual by the way was going to be available in 4 weeks.

Rather than describe the "quality" of the manual and absolute dearth of info in it I will offer it here for sale for $10 plus postage. The buyer can also have my place in line and discount. When you then get the manual and read it you can be just as PO ed as I was for spending a hundred bucks and feeling like someone who had just been taken in a phone scam.

I try not to bash businesses but for those of you familiar with the Blue Mountain G4 launch fiasco it pales in comparison to these guys.

They start a publicity campaign, get a bunch of enthusiasts interested, sell a bunch of manuals and a couple of engines that get put on planes and the the website starts to describe a few minor problems followed by years of well we are getting new engineers...new test equipment...developing a new fuel controller.....etc. etc.

If you buy my manual and place in line I suggest you be under 15 years of age. Then maybe you can get a working engine when you retire. That is if they kept records of the manual purchases and promises.
 
Hey Tom, welcome to the forum.

Turbine Rocket------I like it:D

Thanks for the kind word of welcome.



I'm surprised, sort of by all the negative stuff in here.

I'm not posting here to defend innodyne and their business practices.

I'm posting here because I like turbines better than recips. They are more reliable. They give better power to weight performance, and perform better at higher altitudes than non super/tubro charged recips.

But for the reasons I've posted In my first post I'm not convienced a Van's is an ideal application for one, nor will innodyne beable to develope one, but I'd like to be convinced.
 
This month's Sport Aviation

....has a Legend in the "what our members are building" section. He had a 600 HP turbine it it but it wasn't enough so he put in a Garrett TPE33 with 1000HP! He now routinely cruises at 375 Knots at 25,000'. He says it'll do 400 KTAS, no problem. Sounds like what you'd like..:D

Regards,
 
Thanks for the kind word of welcome.



I'm surprised, sort of by all the negative stuff in here.

I'm not posting here to defend innodyne and their business practices.

I'm posting here because I like turbines better than recips. They are more reliable. They give better power to weight performance, and perform better at higher altitudes than non super/tubro charged recips.

But for the reasons I've posted In my first post I'm not convienced a Van's is an ideal application for one, nor will innodyne beable to develope one, but I'd like to be convinced.

Most commercially developed turbines are more reliable than reciprocating engines but the Innodyne is completely unproven at this point. It is a massive technical and financial undertaking to develop a cheap and reliable gas turbine engine. Don't be first in line to buy anything like this.
 
You have to learn how to interpret what these new engine inventors say and where they're at in their "timeline" to production.

A. If they have a nice website and, and have a prototype built, that means that they are never going to build that engine for production. The prototype was just to gather up a bunch of investor's money before relocating to Aruba.

Vern,
I like your thinking. I think this also applies to avionics "inventors" as well :p
 
"Inventors"

Vern,
I like your thinking. I think this also applies to avionics "inventors" as well :p

I agree and like the thinking. After almost 70 years the turbine engine doesn't need "inventors" it needs engineers. But before it needs engineers there has to be a market for the product. If there was a viable market for a small turboprop the large manufacturers like GE, Honeywell, and Rolls Royce would jump in.

Here is an interesting read on a few of the engineering realities of building small turboprops. It is 13 years old, but I don't think the physics have changed. :)

http://www.provide.net/~pratt1/ambuilt/turbine.htm

John Clark
RV8 N18U "Sunshine"
KSBA
 
I agree and like the thinking. After almost 70 years the turbine engine doesn't need "inventors" it needs engineers. But before it needs engineers there has to be a market for the product. If there was a viable market for a small turboprop the large manufacturers like GE, Honeywell, and Rolls Royce would jump in.

Here is an interesting read on a few of the engineering realities of building small turboprops. It is 13 years old, but I don't think the physics have changed. :)

http://www.provide.net/~pratt1/ambuilt/turbine.htm

John Clark
RV8 N18U "Sunshine"
KSBA

Thanks for a great read.
 
The University of Kansas is testing the Innodyn turbine for use in its Meridian UAV. So far, the results are not encouraging, a lot of technical problems and the fuel consumption is so high that the weight of the additional fuel more than cancels out the weight advantage of the turbine in comparison with a Thielert Diesel:

https://www.cresis.ku.edu/research/tech_reports/TechRpt124.pdf

"The most significant change was that of moving to the Thielert diesel engine over the Innodyn turboprop engine. This decision was made based on unreliability in the testing of the Innodyn engine. This engine is a new and therefore susceptible to bugs. A series of hot starts and hot spots in the engine have delayed the engine testing, which is critical as the specific fuel consumption of the Innodyn has not been fully characterized. The Thielert engine, which was the back-up engine at the time of the CDR, has become the primary engine for the Meridian. The testing of the Innodyn will continue as planned. The Innodyn will be considered for future growth of the Meridian.
The decision to change the engine had several impacts on the design in terms of geometry, weight and balance, and performance. The net effect, however, was minimal due to the key differences in the engines. The Thielert engine weighs 330 lbs where the Innodyn weighs only 188 lbs. This, however is offset by the fact that the Innodyn has nearly double the s.f.c. of the Thielert (0.90 lbs/hp-hr and 0.36 lbs/hp-hr) respectively. The fuel required for the Meridian with the Innodyn is 295 lbs. The fuel required for the Meridian with the Thielert engine is 120 lbs, resulting in a weight savings of 175 lbs. This almost directly offsets the difference in engine weight."
.
.
.
"The current design configuration of the Meridian is a single engine aircraft with a propeller in a puller configuration. The basis of the choice was to keep the propulsion system simple while minimizing fuel consumption. At the time of the CDR, there were two possible engine candidates for the proposed UAV; the Innodyn 165TE turbo-propeller and the Thielert Centurion 2.0 Diesel engines. Pictures of these engines are shown in Figure 8.1 and Figure 8.2 respectively. A third engine, the Rotax 914 piston engine has also been considered, but there are no plans for its acquisition and testing at this time. The Innodyn engine was acquired in the fall of 2006 and has been undergoing testing with disappointing results. For this reason the primary engine has been changed to the Thielert Centurion.
The engine testing of the Innodyn will continue as this is still a viable option for future versions of the Meridian aircraft. The engines will be tested at the Mal Harned Propulsion Laboratory located at Lawrence airport. The performance of the propulsion system depends not only on the engine performance but also the characteristics of the propeller, air inlet and the exhaust nozzle used."
 
Surprise?

:eek:
Thanks for the kind word of welcome.

I'm surprised, sort of by all the negative stuff in here.

I'm not posting here to defend innodyne and their business practices.

I'm posting here because I like turbines better than recips. They are more reliable. They give better power to weight performance, and perform better at higher altitudes than non super/tubro charged recips.

But for the reasons I've posted In my first post I'm not convienced a Van's is an ideal application for one, nor will innodyne beable to develope one, but I'd like to be convinced.
Tom we are just trying to protect you, and frankly its just honest unvarnished opinions, based on facts. There are a lot of very technical folks here as well as jet jockeys. One cold truth is the economics of owning a small turbine GA plane for personal pleasure flying 100 or 150 hours a year, it's just not practical.

You are flying T-6 Texan II with a real turbine, right, with Pratt & Whitney PT6A-68 turboprop, 1,100 shp (820 kW). Yea I would want a PT6 as well, but comparing the Innodyn to a PT6 is like comparing a kids toy matchbox car to a real Formula race car. One is pushed by a little boys dream and the other is real. :D (its a joke and a pretty good one may I say..)

A real Turbine PT6, with prop and all the controllers would cost what...... 1/4 to 1/3 million dollars, just the engine/prop, used? Not many little GA planes can handle 1000 hp. If you want turbine than the best bet right now is Lancair's IVP with a PT6 clone from eastern europe. Apparently you can buy the engines out of old commuter planes, used for $100,000-$150,000. You are looking for about $500,000 to $750,000 to finish a Turbine Lancair IV-Pressurized. Instead of 9 gal/hr for a Lycoming you are looking at 30-40 gal/hr (245 lbs/hr) burn, double for take off? So $200/hr for gas. I'm just not that rich. A RV-10 just can't handle more than approx 260hp, Vne/Mmo wise. What altitude does a T-6 Texan II fly at for X-C, FL250? All RV's are unpressurized and not approved to fly in ice. Are you going to suck O2 from a mask?

Piston engines ROCK in the under 300-350HP range! If you start to need 600-750HP, turbines start to look more attractive, especially if you fly them 2,500 hours a year and are making money with them. Turbines are more reliable. Turbine maintence can be scheduled more accurately, no doubt. Most GA guys fly X-C in the 080 to 120 altitude range, with good efficiency, O2 mask not needed. A turbine would be a gas hog at these altitudes.

It is the economics of scale. There are no (real) turbines that are cheap. It cost almost as much to make a real 250HP aircraft turbo prop engine as a 1000hp one. I don't know your economics, but if you want a real jet than go out and get a used Citation I Jet (can be flown single pilot). Good bargains in Turbo props are the MU-2 Mitsubishi and the Cessna Conquest I, all can be had for less than a million, and you get two turbines.

You like the Texan II? It was originally developed by Pilatus, who also make a great single engine turbo prop for the civilan market, the PC-12. They are fairly new, been around for +15 years and have a very good reputation with the corporate aviation industry. They are like a single engine kingair.
http://en.wikipedia.org/wiki/Pilatus_PC-12
http://www.pilatus-aircraft.com/html/en/products/index_195.asp
(they cost about $4.3 million new and hold value, about min $2.6 mil + for used.)

I'm guessing you are not paying to fly, insurance, hanger, maintenance and fuel right now? Insurance and gas will be way more for a turbine. Tom bottom line these little turbo prop engines are frankly toys, like you would put on a model RC plane, not one carrying humans. There is no fuel control, real RPM control and even torque gauge. It's a jury rig.

RV's are FAST fun planes. Take a fairly inexpensive proven new 160HP or 180HP Lyc, fixed or hyd prop and you will have a fun, high utility plane, with great performance that exceeds most of the GA fleet. Van's philosophy is fun on a budget. You don't need a turbine to have fun. If you want to just fly high and suck oxygen and travel great, but RV's really shine in the sport aviation arena, short fields, sportsman / gentleman's aerobatics and cross country, with great speed, range and payload. RV-10 has shown to be a nice 4 place plane.

The Fact is Innodyn has been around for a long time and has changed names and made endless promises, that they don't keep or are unrealistic. There is a another thread on the topic. At the top of the list is a search drop down menu, search for Innodyn. Look its not negative. In aviation blowing smoke and not realizing limitations of either yourself or equipment can end badly. If you want to be convinced, call Innodyn and talk to a sales person. They will take your money. For fun I wrote Innodyn two weeks ago and nothing. Their web site has not been updated since April 2007. The RV-8T has not flown as far as I know. Beware!

I don't know if you have flown any RV's but if not go out and fly one, any. You will be happy and think the piston engine is pretty cool. You can build an RV two seater for well $80,000 or less. The RV-10 is about $150k? It all depends on what you put into it. You can find used engines, props, rebuild them yourself, etc.. to save some cash, or go all new and gold plate and double the price.

If you are into turbines the Allison (now Rolls Royce) 250 (400hp) and the Garrett TPE31 (600-1100hp) could be good turbines if you could find one. Of course the best is the PT6, but they will cost more than I think you want to spend. Really I am quite serious it will be cheaper to go out and buy the used turbine airplane, even a Cessna Caravan ($2 mil new, $1 mil used), than make one.

Well that settles it:

SFC (lb/hp.hr)
Innodyn 0.65 @ cruise
Diesel 0.36 @ BEP
Rotax 0.48 @ MCP

A Lyc IO-235 or Continental IO-200 with FADEC for a UAV would be in the Rotax range or better 0.45 @ cruise.

The other article was written in 1995, but still has valid points I think we have rehashed here.
 
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And just a short sidenote on top of Georges post - I (and several others) have been proponents of diesel engines such as the Thielert for a while. They burn less fuel (SFC rating), turbocharged, liquid cooled, etc etc, all the great stuff about them - but the price of the Thielert is outta sight (and the fact that they won't currently sell to the experimental market). The DeltaHawk (if you can get one eventually) looks good, but one of the major draws for me was being able to run cheaper fuel (and less of it). Now that road diesel is at $4/gallon and premium auto gas is still running $3.40 (in my neck of the woods), the fuel cost advantage is gone. The diesels are more efficient, but that's currently completely consumed by the price of the fuel.

I still would love to have a turbodiesel upfront - but an IO360 with 8.5:1 pistons for 91 auto gas is looking pretty darn good right now.
 
Biggest advantage of the diesel is that the fuel is already at the airport.
 
Well according to their website they still expect to fly in 2007 which is also their last update.

http://innodyn.com/

Maybe my great great grandson will eventually get to put one on an airplane.
 
well i guess the honeymoon is over.

looks like Innodyn is out of business. i tried calling them and their numbers are disconnected.

looks like vaporware is just that..........VAPORware...

Jeff
 
So does anyone know the typical fuel burn of something like a 737?
And a BSFC not a TSFC?

I have read a difference of 30 to 40% between a Jet and turbo prop, is that about right?
I'd say with modern engineering a PRT diesel recip would beat the pants off any thing in the commercial sky right now especially since some years back the talk was moving away from Turbofans to strictly turbo props.

I think the biggest draw back to any turbine is the speed it runs at. And the massive centrifugal loads imposed by that. Then the vibrations and heat stresses, I'm suprized they do as good as they do. The gear sets that run accessories and prop reduction go through h..... with that speed.
 
I think the original B-737 with the small by-pass P&W JT-8's burned around 3000 lbs/hr per engine at typical cruise speed and altitude (FL350). I'm pretty sure it had a version of the same JT-8 I flew in the DC-9, 727, and DC-8. The later high by-pass GE or CFM engines got about 30% better fuel efficiency. On our DC-8's cruise fuel consumption went from 12,000 lbs/hr (3,000 X 4) to around 9,000 lbs/hr with the CFM 'Dolly Parton' engines. On average jet A weighs 6.7 lbs/gal. I never saw it filled, but when filled the DC-8 carried 159,000 pounds of Jet A. As a comparison, our 767-ER's also carried 160,000 lbs. and burned slightly more fuel per hour (10,000 or so) on two engines rather than four.
The Innodyne is miniature but the sound of it sucking fuel can be heard - from quite a distance!!!

Scott
 
So does anyone know the typical fuel burn of something like a 737?

At what point in the flight profile? Takeoff, or cruise?

I shoulda looked when my friend let me at the controls of the 737-200 simulator. Gross weight was about twice a fully loaded Phantom, so I'll guess that fuel burn at takeoff was also about twice for 24,000lbs / hr / engine, or about 7,300 gallons / hr / engine.

Someone here will know more precisely. At cruise at 36,000' the newer turbofans are about as efficient as a turboprop, and fuel burn would be around 15-20% of full-throttle takeoff (again a rough guess).
 
If you spent any money with them, then at least you got the part of the honeymoon that you probably look forward to the most..........:eek:

Ron - that was beautifully stated!

Here's a link to an interesting and technical thread on using this turbine in a Cub. About 1/2 way down someone very involved in turbine design posted a ton of great information on the problems. It's interesting reading.

http://www.supercub.org/phpbb2/viewtopic.php?p=79429
 
Dreaming is free / Engineering takes $$

well i guess the honeymoon is over.

looks like Innodyn is out of business. i tried calling them and their numbers are disconnected.

looks like vaporware is just that..........VAPORware...

Jeff

When I first read about it quite a few years ago it sounded cool, and also seemed like it might have some real possibilities. Then they actually posted some specs. and that immediately showed it wasn't going to be viable (at least in an RV). If I remember the specs. correctly (no guarantee there); it burned something like 7 gph at idle, and 15 gph up to 15K. If you could cruise at 20K+ you could get that down further to somewhere around 13 GPH. With those extremely high fuel burn rates, it immediately became apparent to all that the engine would be unsuitable for RV's since they simply don't carry enough internal fuel to provide much by way of cross country capability.

Doug Lomheim
RV-9A; 13B...expecting .49 -.55 BSFC from Mazda 13B
 
When I first read about it quite a few years ago it sounded cool, and also seemed like it might have some real possibilities. Then they actually posted some specs. and that immediately showed it wasn't going to be viable (at least in an RV). If I remember the specs. correctly (no guarantee there); it burned something like 7 gph at idle, and 15 gph up to 15K. If you could cruise at 20K+ you could get that down further to somewhere around 13 GPH. With those extremely high fuel burn rates, it immediately became apparent to all that the engine would be unsuitable for RV's since they simply don't carry enough internal fuel to provide much by way of cross country capability.

Doug Lomheim
RV-9A; 13B...expecting .49 -.55 BSFC from Mazda 13B

Yep - magic hasn't happened yet. The latest version of "something like Innodyne" is real:

Velka Bytes Microturbines

However, if I calculated correctly the fuel burn is on the order of 42gph for 250hp.
 
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