Single rotor turbo diesel rotary

Discussion in 'Firewall Forward / Props / Fuel system' started by cheapracer, Oct 19, 2019.

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  1. Oct 22, 2019 #21

    cheapracer

    cheapracer

    cheapracer

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    Been around a long time now, don't hear much about them.

    I guess they are either expensive or they aim them at military drones sales mostly?
     
  2. Oct 22, 2019 #22

    Urquiola

    Urquiola

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    For everyday operation, the critical element in Wankel engine (or perhaps better: Froede, he made the geometrical transformation that made it a practical machine) is Oil.
    If you add a wrong oil, gums and ashes will be produced, clogging seals, it stuck, destroying engine. Experienced users indicate not to rely only on oil meterig pump, but employ at least a 1% oil in fuel directly. Images are from same Yanmar Diesel rotor type, run with 2 different oils from Shell, the clean one had Rotella 30.

    For tuning, can see patents CA1045553; US3848574 -ESPACENET). China had a large Wankel research, see attached image, from SAE paper 880628, Teluan Chen.

    Materials?, basically: aluminum for housings, nickasil for working surface plating, iron for rotor, ferrotic (iron, titanium, ceramic) for apex seals, IKA, as in piston rings, for side seals, are described in the SAE papers by Keller (Sachs), Garside (Norton), Gutmann (Syvaro), Yamamoto (Mazda), Yamaoka (Yanmar Diesel).

    They report GM had a RCE with no need for overhaul in half million miles, but never described the way for this. They discontinued development, reportedly, as being unable to solve fuel economy issues and emissions in same design.
    Any facility producing reciprocating engines can produce Wankel RCEs with little changes. See some patent numbers in Wikipedia.
    Charge Cooled Rotor -Shell Rotella 30 vs Shell X-100 -SAE paper 720466 Yanmar Diesel comp.jpg
    About porting, street car use differs from aviation use, cars run many times at very low load; below 30% load, RCE is worse than reciprocating engine, while airplane engines rarely go below 40-50% continued of top nominal power; as discussed www.rotaryeng.net is a very good site for avionized Mazda and RE in general.
    Low sealing and combustion efficiency, from leaks at low rpm, low load; quenching, flame extinction at high rpm, cause poor RCE performance.
    The Abrams tank has a 294 cc per chamber heavy fuel RCE as APU.
    For road use, perhaps also for aviation, a rectangular peripheral intake port with side exhaust ports can be a good approach, it could be built from RX-8 spares.
    Aixro in Germany produces a 294 cc per chamber, liquid cooled housing, charge cooled rotor, Kart Rotary Engine, 30 to 50 HP depending on versions, lower output for engines supplying continued power. I don't know about the situation of other makers. Salut + RCE research in China -Teluan Chen SAE paper 880628.jpg
     
    Last edited: Oct 22, 2019
  3. Oct 22, 2019 #23

    Billrsv4

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    C.Racer, I certainly understand your comments about "made in where ever". The USA and China have no exclusive rights to the best, or worst engineering. I'm a motorcyclist (and raced.) In the 1980's and early 90's John Britten in New Zealand built a one-off carbon fiber racer. He built the entire bike himself including the engine in his tiny home shop. I still remember the video of him quenching the engine block after heat treating in a drum he filled with water out of his swimming pool! The bike was very successful. Knowledge knows no national boundries.
    The biggest challenge for any new or unusual engine or airframe project is having both the money, and the simple determination to press on and FINISH. You need to have a good enough original design to make sense to persue it. The drive to continue and correct your problems. (And there will be problems.) Until the finished product is reliable and worthy of purchasing. My friend that was one of the two original memebrs of PowerSport the Rotary conversion company. He told me that during their build up to the point that they were ready to take orders, the two of them worked for 2 straight YEARS without a single day off. The story is a sad one as his partner had a fatal crash not at all related to engine failure which ended their venture. Just when they were at the point of release. My point is no matter what the project things can happen that are outside your control. To market a good product takes more than just a good design. It takes the desire and ability to get it done.
     
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  4. Oct 23, 2019 #24

    cheapracer

    cheapracer

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    Know them well.

    My close friend who stays with me when he's over is Ian Drysdale, Google Drysdale V8 and Drysdale Godzilla.

    You will hear the name very soon in relation to light aircraft ...
     
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  5. Oct 23, 2019 #25

    AdrianS

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    I didn't need google :)
     
  6. Oct 23, 2019 #26

    Billrsv4

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    Drysdale originally used the heads for a FZR 400/600 Yamaha with his original V8 IIRC. A Master Fabricator. I found the approach to the Godzilla the rational approach to a big V-twin. Didn't have two weaker rods like the Harleys. The master rod system worked great for the big radial AC engines, with more bearing area for the crankpin. There are many different ways to make a successful engine. I am still wondering about the Chinese single rotor diesel. Everything I have seen rotary wise has not been able to make a high enough compression ratio while running diesel to start it and have a purely compression ignition. The problem is similar to one they were having with early high performance flathead engines. there was such a large combustion chamber area, they were cutting the head closer and closer to the piston. they found that at about 0.015 inches the flame front stopped. The rotary has a similar problem at high compression. The depression area is ok but near the rotor tips the clearance is very close to that flame quenching distance.
    TO Bill
     
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  7. Oct 24, 2019 #27

    Lendo

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    Bille,
    Rotary engines can be run very lean as there is no valves to burn. Any Rotary that breathes straight in and straight out (i.e. Peripheral ported Mazda) has the best Volumetric Efficiency and therefore best power to weight. However I don't know about the Roton motor.
    George
     
  8. Oct 24, 2019 #28

    rv7charlie

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    Meh. You probably don't want to hear it, but most people still operate their carb'd Lycs at about that efficiency.

    The Mazda based a/c conversions are about 5-10% less efficient than a properly leaned Lyc, at 50% lower fuel cost (cheapest 87 octane vs E-free premium mogas, at minimum; 100LL typically.

    Remember, those Rotron engines are aimed at UAVs that might otherwise run a tiny turbine, at a BSFC of closer to 1 than .55.

    Charlie
     
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  9. Oct 24, 2019 #29

    Billrsv4

    Billrsv4

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    Guys and Girls,
    There is something you should understand about the rotary. The closer to maximum power you run it the more efficient it is. Steve Beckham flew the Powersport RV-4 to oshkosh alongside the Vans RV-4. (He knows Van well) The Vans 4 running a O-360 and the Powersport 4 running a P-port 2 rotor with an Airflow Performance aircraft mechanical fuel injection. They returned from Osh togethrer and made every fuel stop together. The Powersport rotary powered RV-4 required LESS fuel to fill up at each fuel stop. They were flying at the same speed, and the same altitude. In aircraft operation where you normally operate at 55% power and above a well tuned rotary gets at least fair, and possibly good mileage. At lower speeds and output, (like in cars) the rotary is at a disadvantage due to its lower torque at low rpms and mileage suffers.
    In regards to Lendo's comment, he is correct that rotarys will run well at leaner fuel air ratios due to their basic construction. My comments about the old flathead engines were to educate some of our forum readers about a phenomonon that was discovered in the 1930's about combustion chambers with very small clearances. Like in a Wankel style rotary engine when trying to raise the compression ratio high enough to acheve compression ignition in a diesel rotary. That is why I first asked CheapRacer if the specifications on the Chinese single rotor indicated if the diesel was spark ignition, at least for starting.
    T.O. Bill
     
  10. Oct 24, 2019 #30

    Bille Floyd

    Bille Floyd

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    In the early 70's , I learned this in the Army :
    Knowing when your Wrong, is (WAY) more important
    than knowing when your correct ; being wrong can Kill Ya !

    So Yea --- i Do, "Want" to hear it ; Thank-you !!

    Bille
     
    Last edited: Oct 24, 2019
  11. Oct 29, 2019 #31

    Urquiola

    Urquiola

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    Yanmar Diesel RCE -Single vs Double Side Port .jpg The fuel economy in Wankel RCE may be more related to load % than to rpm, attached please find an image from a British Study by MR Hayes and DP Bottrill, Mira Alvis ltd, of NSU Spider Wankel engine, and the results by Yanmar Diesel, SAE paper 720466, by adding Reed Valves to Recip Eng & NSU Spider Wankel SFC vs Load charts.jpg intake circuitry, but Airplane engines work most times over 40% load, a good zone. Probably, nothing compares to Single Sleeve-Valve, Burt-McCollum, Bristol type, for fuel economy, .45 lb/ HP/ hr, sport version; .39 lb/ HP/ hr, economy version, see interview with Mike Hewland in Car&Driver, July 1974. -Bricklin car in cover- Salut +
     
    Last edited: Oct 29, 2019

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