Mistral Rotary

[gmcjetpilot]

Originally Posted by Rotary10-RV

I really wonder what your problem is? You obviously won't want one, but many people will. The Mistral package is well thought out and mounts to a standard Dynafocal mount, so you could do an install on any thing using one without tremendous changes. (OK thats great and never said anything about that, but what about the cooling, exhaust.....)

There is test data shown on the site. It isn't hidden, though you may have to use the site map to locate it. They will sell you a engine NOW with a REAL delivery date. I made mention of this because the comments were made in a thread about Inodyne which may never deliver anything. Mistral isn't doing the please send us a deposit for a product that may never be delivered. Any comment to that end is simply malicious and without foundation. (Now you have to read what I said. I made no comparison between the companies, read it. I did say I did not think they where going to make it in the market. I did say the price is too high and they seemed confused about what market they want to be in. You made that connection and it must be in the back of your mind not mine. As far as dynafocal is the engine the same length as a Lycoming ans will bolt to stock mount for lycoming? If so that is nice.)


On several of the Rotary based discussion groups they have been posting results of their normally aspirated 190 HP engine tests regularly. They are running dyno tests almost every day and have hundreds of hours on the Arrow. The Jet-A engine may be of more interest to their customers in europe, but it is running. Paul Lamar who runs the Aircraft Rotary Engine Newsletter has visited the factory which is anything but vaporware. The Mistral PSRU is designed for Hyd/CS from the start which is why I'm interested in it. I consider it to be EXCELLENT value for a new product, which is why I may use it in my aircraft. (Obviously you are doing your home work and going in eyes wide open. As far as excellent value, I will tha'ts subjective. Their quoted price are with no installation, just engine, right.)



Tracy Crook offers a different type of product and MANY people are interested in both. Tracy offers an even BETTER value it just depends on what you want to do. I know you prefer Lyc George. Most people who read any of your posts probably think you're on their payroll. Great that is your preference, don't expect everyone else to follow suit. (I don't think I once said you must do as I say. In fact I don't really care as long as we are all safe out there and don't hurt someone. Again I said Mazda Rocks!, but I do think Lycomings Rocks more, that's all.)


BTW Powersports PSRU costs 6-7000 dollars if you can buy one, just for reference. I think the layout was fine and in fact have communicated repeatedly with the designer of the reduction drive. The Powersport package costs almost the same price as the Mistral package installed. (yes I did not get into a component to component debate. The power sport has been mounted, installed and flown in several RV-8's with good results, that is all. If Mistral as a better, cheaper reduction drive, great, bring it on. Needless to say a driect drive Lycoming eliminates the need for reduction drives.)


A new Mistral 230 HP engine still costs less than a O-540 from Vans if I was to buy both new. The O-540 on Vans site with his discount is $37,500.00, The IO-540 is $42,000. That is a bare engine without an "install kit." You can and may very well do better, but many pony up for a new engine from Vans. They could do the same for less from Mistral and have to do some development fitting the Radiators and oil cooler, that is the big difference.
Bill Jepson (I saw the one wire frame drawing with radiators and "page under constuction, contact the CEO?". You know again I think you are over sensitive. I never compared the Mistral to a Lycoming, you are getting into it, not me. However to be fair you have to compare your rotary to 260HP. I guess they claim 300 HP for the 3 rotor engine. (300hp at the prop sounds inflated, since the RX8 sports car 20B engine is rated at 250hp at 9000rpm!) The 20B would be a better comparison to a 260hp 540 Lyc. The cost will be way more than the 2 rotor 13B, which is not suitable hp for a RV10. I think if I want to get into a apples and apples comparison any engine "KIT" (rotary, subaru) will not be cheaper than a Lycoming. From the kits I have seen cost is not an advantage, but there you go again bringing up Lycomings? Unless you could go the do-it-yourself route, no one is saying the engine "Kits" are cheaper to buy and install. What is the project cost of a 20B from Mistral? You can price out a Lycoming installation out exactly today. You can't do that with Mistral, but again I did not bring this up. The market will speak.)

(Till they make it, install it, fly it, check it, price it and sell it, its a concept, not a reality. Dynos are great but it is not an airplane. I am not impressed with a few 100 hours in almost 2 years and dyno runs, but that is just me, a problem child.)

Bill sorry I did not put my nomex flame suit on, OK, boots and gloves on, now typing.

I stand corrected the rotary is a great engine and should be put on all cars, planes, boats, motorcycles and anything that requires an engine, OK. Mazda engines ROCK! OK I was driving RX2's and RX3's in the 70's (really I was). I never said anything negative about the engine, the late Dr. Felix Wankel or anyone. Mazda's are great fun cars to drive. Well you may detect a little a little sarcasm. I am making a point. Every engine has its pros and cons. OK, but that is not the topic.

As far as Power Sport they have or had planes flying, flight tested by somewhat independent sources (Van's aircraft). Those engines came after 15 years or more of development (started by the late Hatch). The part where they have flown is priceless. RWS also has many units out there. Until a engine is flying in a RV with a total Minstral package and tested I will be super cautious and skeptical of claims of better anything. Again every engine has pros and cons. Its hard to overcome basic principles and limitations.

Someone has to not drink the cool aid. Now calm down, what I mean. Well I said I think the Power Sport and RWS (real world solutions) are already on the market (the former a little shaky by others accounts). My realistic comments are I don't think Minstral will sell many at $31,500 dollars (my opinion, hope I am wrong). I also am pretty sure it will not do anything better than all the other 13B's out there. The 20B sounds interesting but that is even further out than the 13B. I will be happy to be proved wrong. I also have noted correctly that they don't seem to know what market they want to pursue, certified or experimental(?). None of this gives me warm fuzzies.

As far as flight test data I did not find it. Their weight chart is an estimate an I think a little optimistic.


I have been flying and building planes for almost 3 decades and love all things that bun gas and make noise. So accuse me working for Lycoming if you will; yes they do Rock; lets just say I am opinionated and have as much right as you to say what I want, as long as it is not personal and thoughtful. I am not wishy washy about it. New engines or new companies have to prove themselves; its too important, lives depend on it. I have stayed on point by the way have not broke into any advertisement for the ROCKING Lycoming!! Woo-Woo, Yea, all right, yahoooo. You brought up Lycoming. I don't think we need to attack Lyc's to make something look good. However it is the gold standard for light aircraft.

With that said no hard feelings but lets face facts, and let them speak for themselves. I am eager to see how the new 3-rotor works in the RV-10. It could be a sweet spot? Who knows? Not many have experience with it. I am not negative just realistic. I want Mistral Reduction Hyd/Prop and EFI to be the most rocking thing to hit the airwaves. I am just not going to get excited myself, and I criticize no one for going where no man has gone before. It is important to vent all the pros and cons, and you have done a great job bringing out little know facts for the Pros of this new engine supplier. There are for folks looking into alternative engines who are new the home building. They need to hear both sides.


When I say, "It is my opinion they will not make it to the market", I think that is a bet I would make. You say they are not more than Power Sport. Hey PS is a good product and they are struggling. That is my whole point. It is hard to compete with brand NEW Lyc (clones) for $20K, not withstanding the 540's.

I write as if I was giving a good friend advice. I Sincerely believe what I write and would not invest in a Mistral at this time as I said, until they where flying many many engines. In my opinion that is way off in the future at the speed they are going. We have to temper enthusiasm with facts. If I was buying a Rotary kit it would be Power Sport, or make my own using RWS stuff hands down. The interesting thing about Mistral is that hydraulic constant speed prop reduction drive. May be that will be a cool thing, but I would wait to see what the cost, weight and some service history. Hey it is not a new piece of avionics. This is serious business. If the prop stops, for what ever the reason, is could kill you. Proceed with caution on new technology.

I guess that is my problem, I am super conservative and error in caution. New engines, drives, EFI or what ever have to prove themselves before I will put my butt or a passenger behind it. George

[mlw450802]

quote from GMCJETPILOT? "since the RX8 sports car 20B engine is rated at 250hp at 9000rpm!"

Actually the Renesis engine is very much like a 2 rotor 13B.

A 20B with similar treatment might be ~375 HP @ 9000 rpm.
(125HP per rotor)

-mike

[cjensen]

Originally Posted by mlw450802

quote from GMCJETPILOT? "since the RX8 sports car 20B engine is rated at 250hp at 9000rpm!"

Actually the Renesis engine is very much like a 2 rotor 13B.

the renesis engine IS a 13B. it's a 13B-REW with 250 hp.

mickey, i think we would all love to see some pics and a tour report if you get a chance to go down there!

[Rotary10-RV]

All,
The Renesis engine used in the RX-8 sports car is a 2 rotor. It differs from the earlier RX-7 engine by having all the intake and exhaust functions passing through the side plates. Mazda did this to enable them to run larger ports without overlap problems. Almost all of these changes were done to enable the engine to work better in automotive use. That is to run better at lower RPM. The higher HP is as a result of larger ports and higher RPM operation. The Renesis (stupid name) is redlined at 9k. The rotary will operate at those RPM's easily, but for aircraft use I would prefer to derate the engine somewhat for total reliability. Additionally the Renesis comes in 2 flavors, Manual and Automatic. The manual trans engine has the 6 intake ports and makes 235 approx. HP at 8700 RPM. The automatic engine has 4 intake ports and makes about 200 HP. This is normally aspirated, not turbocharged.
The basis for Mistral's 2 rotor engines is the earlier 13B engine. They will be doing a complete engine, (not Mazda), as this is required for certification tracking. The geometry of the engines, the shape of the housings and offset of the excentric shaft is the same.
The 230 HP Mistral engine is turbocharged, and would make a excellent RV-10 engine. It provides enough power down low and will provide superior power at higher altitudes than a IO-540 Lycoming. (Watch that TAS an altitude) I plan to use a NA 20B 3 rotor, Derated to 250 or so HP. Max RPM will be about 6k in my operation.
Bill Jepson
Rotary10-RV

[gmcjetpilot]

I am confused, but this is where I got my info:

http://cp_www.tripod.com/rotary/pg20.htm


What I gather, 3 rotor engines have been made for a while (Cosmo) and came in at 280 hp to 450 hp for flat out racing engines. The cost of a core is $20,000, bare. I assume the designation was 20B. I don't think I mentioned "Renesis", but did mention the RX8, which has the 2-rotor Renesis 13B? I guess the 13B Renesis is rated at 250hp in the car. If installed in a plane, not at 9000RPM and going thru a reduction drive, the HP at the prop will be? I don't think its 250HP.

The normally aspirated 3 rotor rotary that mistral post has 300Hp is a lot, but like the 13B, I would be surprised if at "normal" rpms and by the time you get to the prop you would have more than 260Hp. I could be wrong, and I am guessing since I don't think there is too much info here.

The 20B turbo seems to be the hot thing, but it will not be cheap or easy to do. Mistral 360-TS is claimed to put out 360hp (at what rpm). HP cost gas there is not free lunch. In the end will it be better than a IO540 or 540 turbo-ed? We will see. On Mistral's site no price is quoted, and installation is so important with a turbo.

Based on the modular feature and from what I know about a 13B, the most HP you can can expect to get at the prop is about 80-90 hp per rotor. (at least non-turbo. Remember you are not running 9000 rpm and you have a reduction dive, which looses some efficiency. So I guess to get the power you are committed to turbos, with more efficiency and yes power. It seems the best way to get the power and efficiency from any auto alternative. With that said there is added cost, complexity and maintenance.

Also Tracy of RWS runs his 13B RV-4 in the 160hp class and does pretty well. Why does he not race in the 180hp ore open class? If he raced in the 180hp RV class, his times would not fair so high in the pack. My point HP quoted is meaningless unless it translate to HP at the prop and airspeed.

With that said the last Power Sport engine kits (the most complete rotary package around: mounts, radiators, cowl....) did fairly well and matched the performance of a 180 Lyc RV (in fly off with Van's RV-8 prototype published in the RVator). However (don't hate me) the rotary did this at the expense of significant greater fuel burn and yes, noise. The good news is the weight was not grossly higher, and not to be over looked the performance did come up to the Lycoming. This is really good and significant. Most of the auto conversions have fallen short of the standard speeds set by Lycoming. My theory is cooling drag is too high. The Power sport with the custom cowl seemed to recover a little cooling drag reduction.

That is why I get all excited about installation. HP means nothing if you have big gap-ping holes in your airframe. Look air-cooled engine cooling drag has been optimized for over 80years and studied and tested on military fighters, NASA and universuty for decases. For any company to be a success in this market they have to offer a complete package, not just the engine.

Egg does well in the complete part, but in my opinion (as an engineer, pilot) it is far from optimal. Nice yes, optimal no. Retrofitting to an airframe that is designed abound an aircooled engine is going to be a compromise unless someone does a blank page design. I could see where you by a kit and build it into the airframe, well before mounting the engine. Cooling tunnels, embedded radiators in the firewall, fuselage? My point is the use of water cooled engines in RV's is in it's infancy. A breakthrough installation has yet to be designed and flown on a RV, but it is getting better all the time. Keep going. When you all figure it out and get the cost down, I will come in and shamelessly copy it.

What ever Power Sport did, it should be copied. I hope they continue to stay in the game or at least their efforts continues by someone. George.

[rv6ejguy]

I too liked the professional approach of the Powersport Wankels, especially their redrive development and testing however their fuel flow numbers and ECU development and programming appeared to be inferior to some of the developments by Mistral and RWS if you can believe published numbers. I award high points to Powersport for flying two RV8s down to Van's and doing head to head testing. They have been the only auto engined converters to have had the confidence in their product to do so to date.

I also believe after much flight testing and experimentation that Powersport's radiator setup, despite being cool looking was a relatively high drag solution. I've done much research into this area on our RV6A testbed and detailed examination of WWII radiator installations and believe that a dedicated rad duct offers much lower cooling drag penalties than most currently used setups. Recent flow bench testing shows a massive difference in pressure drop between different heat exchanger types. This is equally important in the cooling drag equation.

The lowest drag solutions are undoubtedly those using scientifically selected heat exchangers in a dedicated and properly shaped duct with the cooling system installation having primary importance in the design. The best historical designs being the DB powered D series FW 190 and TA 152 with ring radiators and the P51 with its cooling system designed into the airframe rather than onto it. Honorable mention goes to the leading edge rad installations in the twin engined DeHavilland Hornet. The Hornet in particular is very impressive with 2070 hp RR Merlin 130-131 engines rated to perform up to 35,000 feet, with the layered coolant, oil and charge air heat exchangers and 485 mph top speed (430 mph cruise!) has exceptionally compact setups. These were built before aluminum furnace brazed heat exchangers that we have today were available. These chaps have forgotten more than we're ever likely to know about liquid cooled aero engines.

Analysis of radiator face area, volume, inlet and exit areas and installed hp of these in particular indicate much higher efficiencies and lower drag than every single liquid cooled experimental aircraft flying today that I have examined except for one Chevy powered Velocity which used a dedicated boundary layer type scoop, modern heat exchanger and exceptionally small face, volume and inlet area.

Unfortunately, it can be difficult to integrate a good radiator installation on an aircraft designed for an air cooled engine from the start. I agree with GMC here, there is much work to be done in this area to arrive at a low drag solution rather than just getting the job done irregardless of the drag penalty.

Certainly low cost has been a factor in experimental aircraft but a couple GM evaporator cores or similar jammmed behind the cheek inlets is far from optimal. That being said, there are other design parameters and considerations that are important. Ease of installation, weight and routing of lines makes this approach attractive for firewall forward bolt ups in one assembly like the Eggenfellner packages.

[rv8ch]

As I promised, I went to see Mistral last week, and did a little 3 article writeup one what I learned. Seems like good stuff to me!

http://www.rv8.ch/article.php?story=20060202202829108

[gmcjetpilot]

Originally Posted by rv8ch

As I promised, I went to see Mistral last week, and did a little 3 article writeup one what I learned. Seems like good stuff to me!

Thanks Mick, do you have any data on fuel burn/hp besides the 0.45 lb / hp number. That's good and is in fact right up with the Lyc. They did that how? Dual plugs is standard on a 13B. Better intake, dual injector and elctronics sounds interesting. I would like to know how that works. Interesting.

I also like the dynafocal mount, so I assume the crank flange face is right where it would be on a Lyc. Brilliant, awesome idea using existing mounts.

Full up installed weight in an aircraft would be another good number to know.

I think three things are in the way. Cost, must come down. Second is weight control, must be no more than an equivalent Lyc. Third and last, a low drag radiator installation. If they can get it certified and meet the three challenges and make the fuel flow they claim it will be a success. It is a little company right now with a big empty plate to fill, but micro soft and apple where small companies at one time to.

Looks interesting and wish them the best of luck. I really like to see there future 3 rotor engine.
George

[rv8ch]

Originally Posted by gmcjetpilot

Thanks Mick, do you have any data on fuel burn/hp besides the 0.45 lb / hp number.

Francois gave me this foil, which I just scanned, so I hope he's ok with me posting it. They said that installed engine weight is about the same as with a lycoming 360.



They have some good information on costs, but I'll let them sell the engine. I just wanted provide some impressions from a disinterested third party, since I live close to their facilities.

[cjensen]

great write up mickey! thanks for taking the time to visit their facility. it's so nice to have this community set up where we can take advantage of the locale of so many people around the world to give us first hand accounts of companies and interests that some of just can't do at this time. i, for one, really appreciate your visit and info!

thanks.