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Unofficial time to climb record to 10K feet (with Mazda power)

Awesome. Was this FAI observed? Nice to see an auto engine powered RV derivative do this sort of time. Only 9 seconds behind the outright record held by Rare Bear.
 
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Yes, no, maybe...

Yes, an FAI observer was present for the attempt. It's not on the NAA or FAI site yet, but it takes many weeks to finally post. (discovered through my own experiences with the process).
As you know a video of his test flight/first unofficial attempt was posted several weeks ago on DR's VAF homepage and one of many thread responses included someone familiar with the builder/pilot. The cowling was left off for weight reduction and cooling of the turbocharged Mazda Rotary.
Impressive indeed, considering it's a one off personally built aircraft with a modified automobile power-plant. Craig Catto's genius Gen 3 out front is no surprise.

Despite living in a Space Age/Lockheed Martin Skunk Works techno-world, the spirit of the Wright Bros. lives, and thrives..:)

V/R
Smokey

http://www.vansairforce.com/community/showthread.php?t=158749&highlight=time+climb
Here is the original thread
 
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The claim is this engine makes 650hp. At that power level, what would be the expected lifespan of the engine?

(Not tossing bricks, just wondering if this would be a single-use engine for this climb attempt, or whether it might be able to make that kind of HP for longer periods of time. Curiosity, not criticism.)

The deck angle was pretty impressive, but I had to laugh at that poor old analog altimeter trying to keep up with the climb!
 
I'd say totally unknown. It's a unique build, with aluminum end housings (norm is iron) and a monster turbo. A lot of the build decisions seemed to mimic unlimited Reno racers. Having said that, the ones with iron end housings seem to survive well at similar power ratings in racing (totally different environment). Previous record in that subclass was hald by Elliott Seguin with an IO550, that you can bet had a *very* short life. The 13B displacement is 80 cu in. I think that total engine weight (with turbo) for the TTC engine is under 200 lbs.
 
Just wondering why no cowling... wouldn't that have helped with drag and specially cooling

The vertical component was about 63 knots, best ROC maybe around 85 knots, really not much drag at that speed. Power to weight is king for this contest and it has to cool at this low speed. Seems like a good decision to leave the cowling off for this attempt. Think of all the glass worked that they saved. :)

The methanol fuel would have helped cooling, power and charge temps a bunch, another good decision.

It was an innovative, relatively low cost way to take the record. It worked. My hat is off to the team.
 
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Pistons? We ain't got no steenking pistons!

Potential new record for (all) piston powered airplanes: 1 minute 40 seconds.

RV-4/Rocket with turbo'd all aluminum Mazda 13B rotary.
https://www.youtube.com/watch?v=k_gedJrWbT4

The record attempt says 'internal combustion engine' - not 'piston engine'.

No matter how you look at it, that aircraft really does the mission well.

Did Elliot fly a methanol fueled 550 in his attempt? If not, there might be someone to challenge this record using the different fuel...hopefully using a Bearcat running on methanol. I'd travel a long way to see that!
 
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C J,

Following up on the durability question, back on an actual keyboard. In general, rotaries are pretty hard to kill. The E-shaft (crank) and its bearings are very tough; truly massive boost and/or rpm north of 10K is usually required to even make them vulnerable. Weakest point(s) in highly boosted rotaries are usually the apex seals of the rotors, but even that's been pretty well handled these days.

Only tangentially related, but one of the issues they ran into is, that massive prop apparently still left them under-propped, so they weren't using the engine's max potential. They were also using that Rocket wing. A highly questionable choice for a mission that's run entirely at high angle of attack, where stubby wings have such a high drag coefficient. Imagine the results with a proper prop and a proper wing for the attempt...

Charlie
 
The Wankel is a very lightweight, powerful package, tied to a gearbox which allows much higher revs and power production than a direct drive engine of even 50% more weight. Even a super high boost Conti or Lyc won't match the ENGINE power to weight ratio of this package though they put out quite a bit more power.

Certainly this record can be beaten too but probably not for less than what these guys have invested. You gotta appreciate what they've done here. They smashed the old record in class at a fraction of the cost.
 
Wing

They were also using that Rocket wing. A highly questionable choice for a mission that's run entirely at high angle of attack, where stubby wings have such a high drag coefficient. Imagine the results with a proper prop and a proper wing for the attempt...
Charlie

The wing choice may not be as bad as you think. At very high pitch angles, the prop is producing a significant amount of the "lift" therefore the wing's angle of attack may be pretty low. An extreme example of this is a plane in a purely vertical climb (0 lift from the wings/0 angle of attack).

Bruce Bohannon had pretty good success with low aspect ratio wings on the Flying Tiger.

Skylor
 
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I'd say totally unknown. It's a unique build, with aluminum end housings (norm is iron) and a monster turbo. A lot of the build decisions seemed to mimic unlimited Reno racers. Having said that, the ones with iron end housings seem to survive well at similar power ratings in racing (totally different environment). Previous record in that subclass was hald by Elliott Seguin with an IO550, that you can bet had a *very* short life. The 13B displacement is 80 cu in. I think that total engine weight (with turbo) for the TTC engine is under 200 lbs.

Thanks for sharing this analysis.

I would bet the rebuild of the IO550 would cost a bunch more than the rebuild of the 13B! :)
 
Awesome. Was this FAI observed? Nice to see an auto engine powered RV derivative do this sort of time. Only 9 seconds behind the outright record held by Rare Bear.

Awesome is right. But we may not have heard the last of these guys. There is a lot more potential if that engine comes close to 650 hp.

The back-of-the-envelope numbers for this flight are:
Approximately 180 thrust horsepower for the climb rate (6000 fpm) and another 50 to fly the plane, maybe 100 with the cowl off.

Eyeballing the prop, the diameter is about, what?, 80 inches. It looks big. But, at 90 knot or so pushing that prop with 650 HP, the MAXIMUM propeller efficiency possible can only be about 50%. Surprisingly, for this application, the prop is tiny. This means 300 HP or so is being flushed down the slipsteam.

So, the game will be: more prop diameter(gearbox?) and/or go faster(cowling,etc.)


BTW, their site had the FAI record application for climb to 3000 meters posted.
 
Thanks for sharing this analysis.

I would bet the rebuild of the IO550 would cost a bunch more than the rebuild of the 13B! :)

I found an article about the previous record holder, titled 'High Desert Tales', in the Feb 2016 issue of Kitplanes. It's Lynn Farnsworth's Lancair Legacy Reno Racer. So.... yes, it would cost 'a bit' more, and have lifespan measured in minutes; not hours.

That particular rotary would be a bit pricey to OH, if the custom aluminum end housings had to be replaced. But a complete overhaul kit for the iron housing engines would cost somewhere between one & two cylinders of a stock IO550 engine, depending on whether it needed bearings (very unlikely, at normal rated power levels of around 90-100 hp per rotor).

On the prop issue: The gearbox is a 3:1 ratio from a Bell 47 helicopter. Larger dia prop would obviously be better, but there's the ground clearance issue. There's also tip speed to consider; the engine is running at north of 8k rpm, so the prop is turning at close to 2700 now. Four or five blades might be easier to do, though admittedly not as great for mass flow. Pitch control would probably help, too, as the air thins in the climb.

Charlie
 
There's probably more left in this design should they wish to tweak. This record has been broken several times in the past 5-6 years- Lee Behel in the GP5, Elliot Seguin most recently.

The Wankel is way cheaper than a typical 540 or 550 race engine but you'd be surprised how long these can last. The Lycon built Conti 550 in the 2010 Sport class Gold winner had 4 seasons of Reno racing, plus lots of test flying and some cross country work on without being taken apart. This was pushing nearly 800hp in race trim. There are more powerful Lyconentals running at Reno now and the Falconer V12s are pushing WELL over 1000hp.

The future for time to climb records is not in direct drive air cooled engines though as they cannot hope to match the power density or power to weight ratio of geared, liquid cooled engines. I don't doubt someone will come along some day with a 1000+HP V8 powered design with a CS prop which will break this record again. It only takes the will and some money.
 
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I'd say totally unknown. It's a unique build, with aluminum end housings (norm is iron) and a monster turbo. A lot of the build decisions seemed to mimic unlimited Reno racers. Having said that, the ones with iron end housings seem to survive well at similar power ratings in racing (totally different environment). Previous record in that subclass was hald by Elliott Seguin with an IO550, that you can bet had a *very* short life. The 13B displacement is 80 cu in. I think that total engine weight (with turbo) for the TTC engine is under 200 lbs.

I agree with Charlie. I would say that the engine is not a "single race", but would likely be "single season" if in a car. Well-funded guys would rebuild at the end of the season and the poor man would run it until it broke an apex seal. Like any engine in extreme race configuration you would not want to use it as your daily flyer, but the engine can tolerate 250hp all day long as long as it is kept cool.

For one-time drag race uses (or dyno testing to impress people), the car guys are getting just shy of 1000 hp out of this engine.
 
How many apex seals were sacrificed in this very impressive attempt?

Don't remember for certain, but I don't think they broke any. They broke a lot of other stuff; some 'interesting' choices & techniques bit them in the hindside along the way. Even had a water injection failure at one point, which would normally be instant death to old style apex seals under heavy boost, but no apex seal failures, that I remember. There are some incredibly tough seals on the market now.
 
Awesome. Was this FAI observed? Nice to see an auto engine powered RV derivative do this sort of time. Only 9 seconds behind the outright record held by Rare Bear.

Well, actually only a little over 8 seconds behind Lyle's retired record. Does anyone know what changes they made to the rules that caused them to retire that record? If it was measured from time of lift-off instead of dead start that would easily make up for the 8 seconds.

I would not be surprised if we are not done seeing records out of this plane. They should be able to get some great sponsors at this point. Too bad the lawyers are scaring away Mazda itself.
 
They retired Lyle's piston speed record too when Voodoo didn't quite beat it by the required amount. Something about retiring the C class if I recall.

I agree on the Wankel Rocket, there is more left in it. All they would have to do is repeat the same test on a winter day and they would take at least 10 seconds off what they already did.

The Bearcat was a bit of a sledgehammer to take the record. The lightweight Rocket just seems like a much less expensive way to approach such things.
 
Another Airframe?

Since maximum climb rate is all they're looking for here, wouldn't it make sense to put the engine into an RV-9 and have a go at it with that bigger wing?

Doug Lomheim
RV-9A Mazda 13B FWF
 
How many apex seals were sacrificed in this very impressive attempt?

Quentin, NONE. The ceramic apex seals available for many years for the rotary are ABSOLUTELY reliable. Mazda used these seals on the outright Le Mans 24 hour win in 1991! Apex seals really haven't been a problem since the late '70s, but misinformation is passed along as gospel by folks that really don't want the Wankel to succeed. Most races classes just end up banning them.
Bill J
 
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