How many people are interested in a GOOD safe psru for the rotary?

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Will Aldridge

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I'm committed to putting a rotary into the plane I'm designing, but it's realistically 10+ years down the road from flying. I'm not in a financial position to be able to commit to buying one of your gearboxes right now, though I have bet heavily on there being a reliable gearbox by the time I'm ready for it. I wish you success and will be watching carefully.
 

Vigilant1

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I wanted to ask if it is possible to post videos on this forum?
Bill
Bill, I'm not a moderator, but I don't know of any prohibition against posting a video. The icon at the top of the "composing" window-- the icon that looks like a filmstrip, if you are old enough to remember those-- will insert the video for you. It can be a link to a web page or to a file on your computer.
 

bmcj

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I don't think you can upload a video file directly, but you can link to or embed a video as long as it already resides on a hosting site like YouTube or one of the many others.
 

Billrsv4

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print-screen-dyno.jpg
OK guys, and hopefully girls, here is a jpeg pulled from one of my videos. The ring on the left of the picture is the surround around dyno prop. This engine is running as I snap shot the frame. It is hard to see most of the features of the engine in this shot. We ran the engine for an hour later in the day, at various RPMs from 2K to over 6. Ran well no problems. PSRU is obvious between the ring to the left and the engine.
Bill
 

Topaz

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I don't think you can upload a video file directly, but you can link to or embed a video as long as it already resides on a hosting site like YouTube or one of the many others.
This is correct. You can't upload a video directly, or link to one on your own computer. If you have video up on YouTube or one of the other hosting services, you can post a link to that using the "insert video link" button, the one that looks like a couple of frames of movie film.
 

Billrsv4

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HBA folks,

OK, We do now finally have a good video up on YouTube. Steve had to post it so he could send it to a friend of ours. This was while we are still working with the Fuel Injection manufacturer to tune the low end of the speed range for ease of idle. Note that there is no worry on our part about the reduction drive just working to tune the engine up a bit. We are limiting the engine to 6000 RPM to start with. This is the smaller ported engine. We think the large port version may over power this prop, forcing it into flutter or stall. this is about 180 HP. At about 6200 it hits 185. We are looking at a different ratio to lower prop speed, but then we would need an even large club for the dyno. The P-port engine is a lot like a piston engine with a big cam at idle. Not the exhaust note. This is a muffler designed to a Heimholtz formula. The odd shape to fit into a space in the RV-3. Enjoy, and give me your comments. Hope the link works

Bill

https://www.youtube.com/watch?v=EfreUJt-Fsk.
 

Will Aldridge

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HBA folks,

OK, We do now finally have a good video up on YouTube. Steve had to post it so he could send it to a friend of ours. This was while we are still working with the Fuel Injection manufacturer to tune the low end of the speed range for ease of idle. Note that there is no worry on our part about the reduction drive just working to tune the engine up a bit. We are limiting the engine to 6000 RPM to start with. This is the smaller ported engine. We think the large port version may over power this prop, forcing it into flutter or stall. this is about 180 HP. At about 6200 it hits 185. We are looking at a different ratio to lower prop speed, but then we would need an even large club for the dyno. The P-port engine is a lot like a piston engine with a big cam at idle. Not the exhaust note. This is a muffler designed to a Heimholtz formula. The odd shape to fit into a space in the RV-3. Enjoy, and give me your comments. Hope the link works

Bill

https://www.youtube.com/watch?v=EfreUJt-Fsk.
Looks pretty good from what I can see. A few questions though;
1. Is the prop shaft in line with the e-shaft like the Ross and Tracy redrives?
2. What is the distance from the prop flange to the face of the engine?
3. Where do you have the starter located?

Thanks,

Will
 

Billrsv4

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Looks pretty good from what I can see. A few questions though;
1. Is the prop shaft in line with the e-shaft like the Ross and Tracy redrives?
2. What is the distance from the prop flange to the face of the engine?
3. Where do you have the starter located?

Thanks,

Will
Will,
No the prop shaft is NOT in line. It is offset about 2-1/2". This is a good thing IMO. The reason is that when in line the top of the cowl line is too low to fit a intake tube over the engine.if you want to be able to fit a plenum under the cowl you need to put it on the plug side. On an earlier version of this engine project with a planetary gearbox it be to be mounted plugs up to fit under the cowl. Don g so is difficult and requires either fabrication of a complex sump or running a dry sump. Expensive. The starter is along the plug side towards the rear.
Bill
 

Billrsv4

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Looks pretty good from what I can see. A few questions though;
1. Is the prop shaft in line with the e-shaft like the Ross and Tracy redrives?
2. What is the distance from the prop flange to the face of the engine?
3. Where do you have the starter located?

Thanks,

Will
Will, For got in the previous reply on the prototype the flange to engine distance is approx 12.5" I don't have the drawings in front of me right now.
Bill
 

Will Aldridge

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Will,
No the prop shaft is NOT in line. It is offset about 2-1/2". This is a good thing IMO. The reason is that when in line the top of the cowl line is too low to fit a intake tube over the engine.if you want to be able to fit a plenum under the cowl you need to put it on the plug side. On an earlier version of this engine project with a planetary gearbox it be to be mounted plugs up to fit under the cowl. Don g so is difficult and requires either fabrication of a complex sump or running a dry sump. Expensive. The starter is along the plug side towards the rear.
Bill
Bill,
I designed my plane to look like it has a radial in it so my thrust line is significantly lower than most planes with a flat engine so I've got gobs of space on top but not much underneath. Any chance you could make your box like some of the rotax gear boxes I've seen so it could be mounted up or down? I'd actually like a little more space under my engine.
 

Billrsv4

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Bill,
I designed my plane to look like it has a radial in it so my thrust line is significantly lower than most planes with a flat engine so I've got gobs of space on top but not much underneath. Any chance you could make your box like some of the rotax gear boxes I've seen so it could be mounted up or down? I'd actually like a little more space under my engine.
Will,
It would probably be ok in either direction but since it is Mazda specific in its current form a completely new back plate would need to be designed
 

Billrsv4

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HBA Group,
As I mentioned we have been running the engine PSRU package on the aircraft dyno. We are very pleased with the results. We have done some muffler testing and have excellent news. With a slightly less restrictive muffler than the one shown in the linked video, (remember we sized that muffler to fit into an RV-3), and an updated fuel mapping from the aircraft FI we are running The HP of the small port motor peaked at 190! It is a little bit poorer on the high frequency than our custom muffler but it is the highest number that we have recorded with ports this small. We are now removing the engine from the dyno and mounting it in the RV-3. We have the information we needed and hope to have it installed and flying very soon. I hope the moderator will tolerate my re-posting this in the Mazda rotary category, since some people are likely to have missed its posting in the PSRU discussion area.

Bill
 

wsimpso1

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Knowing the origin of this scheme, I am definitely interested. I am curious as to the bearings in the prop shaft.

Billski
 

Vigilant1

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Bill,
That peripheral porting is a great way to modify these engines for aircraft use. Better breathing (and HP) compared to the stock side port, and lighter, simpler, and more easily fabricated intake manifolds. Looks great.
How has the fuel consumption been while it has been on the stand?

Mark
 

Billrsv4

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Bill,
That peripheral porting is a great way to modify these engines for aircraft use. Better breathing (and HP) compared to the stock side port, and lighter, simpler, and more easily fabricated intake manifolds. Looks great.
How has the fuel consumption been while it has been on the stand?

Mark
Mark,
The initial testing looks pretty good. Fuel flows are comparable to a Lyc of similar HP. (With an engine gearbox package up to 100 pounds lighter.) BSFC in the .4 -.5 range. Rotaries work better the harder you drive them. At max power it looks great, at low power or idle the thermal efficiency of the rotary suffers as does the mileage. Running the aircraft FI and a standard electronic ignition though it does match typical aircraft engines. Peripheral porting with the right length intakes can be very efficient. In fact when my partner flew an earlier version in an RV-4 next to a Lycoming powered RV-4 flying the same speed and the same altitude cross country he used LESS fuel at every fuel stop. We are happy with the fuel consumption. The other thing is that the engine runs great on auto gas or aviation fuel. The best performance we get is with non-alcohol auto fuel of 92 octane UNLEADED. Much cheaper than avgas where available. IF you are a fun flier your fuel bill can be 50% less if you run auto fuel. You also won't have any problem when the FAA finally mandates unleaded fuel. The engine isn't a fuel hog, but in it's current form it is no better than an aircraft engine. I am making this long post because some people dismiss the rotary as "pouring fuel on the ground". This is baloney. if you want to make 200+ HP it is going to take some fuel! One of the most exciting possibilities will be when we equip the engine with a modern electronic engine management system. The rotary has good performance on VERY lean of peak mixtures. This can only be explored on a instrumented and EMS controlled engine but has great promise for cruise or other low power operation. Mixtures of 17:1 have run reliably using EFI and ignition control. This is why Mazda is bringing back the rotary in their new sports car.

The original engines were fitted with Airflow Performance aircraft fuel injection so people would be familiar with it and understand it wasn't a "black box" operation. This is an all holes all the time system that is going to be at it's best at or near wide open throttle. When fitted with a modern EFI/EMS fuel use will only get better. And it isn't bad now.


Bill
 

Lendo

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Bill,
Billski (a Transmission Engineer) asked about Bearings on the prop shaft.
Someone else asked about weight of the PSRU.
Someone else has concerns about power to weight ratio of a single rotor Rotary - what about some superlight Laser Sintered steel housings down the track, when those particular technology costs become more reasonable. I know Powersport developed both Al and oven brazed light steel housings way in the past. What's your opinion on future developments of the Rotary in terms of weight savings like this sort of thing.
I know the single rotor has those bad torque reversals, but I'm sure they could be overcome with some good Torsional Vibration engineering - Bullski might have some suggestions - sorry Billski if I've dropped you in it.
George
 

wsimpso1

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Bill,
Billski (a Transmission Engineer) asked about Bearings on the prop shaft.
Someone else asked about weight of the PSRU.
Someone else has concerns about power to weight ratio of a single rotor Rotary - what about some superlight Laser Sintered steel housings down the track, when those particular technology costs become more reasonable. I know Powersport developed both Al and oven brazed light steel housings way in the past. What's your opinion on future developments of the Rotary in terms of weight savings like this sort of thing.
I know the single rotor has those bad torque reversals, but I'm sure they could be overcome with some good Torsional Vibration engineering - Bullski might have some suggestions - sorry Billski if I've dropped you in it.
George
Sorry, I don't have any magic for you on single rotors Wankels. They would be pretty heavy for the power produced. Several reasons:

Really big counterweights are necessary;
Firing order vibration would be huge, requiring one or both of, torsional pendulums and very long stroke "soft" isolation system.

With only one rotor, the entire eccentric mass of the shaft and rotor has to be balanced with counter weights. With two or more rotors, the primary (up and down) imbalance is taken care of by having the eccentrics evenly distributed, and the counterweights only have to balance the pitching moments. The more rotors, the smaller this whole effect is and less counterweight size needed.

The firing frequency on a single rotor is one per rev and really strong. Torsional pendulums would be useful, but they would have to be really big to tame that low a firing order. A soft system would require pretty low spring rates, which means a lot of travel and volume occupied by the spring system. You might need both...

In the end, Wankel single rotor engines will be heavier and more complex than two rotor engines of the same power.

Billski
 
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