The Pond Racer.....Rutan's Watergate

[Peashooter]

Re: The Pond Racer.....Rutan's Watergate

Michele: A Vari EZ holds the record for CAFE efficiency. (Gary Hertzler) Also, a Long EZ holds the absolute altitude record for its weight class -- over 33,000 ft. on 118 hp. My Long EZ? I hold a point-to-point speed record between CVG & LAL at 206.54 mph on 130 hp, nonstop. And when I arrived at KLAL, I had 18 gallons left. I was running at best power, not economy cruise on the stock fuel capacity of 52 gallons. I will yield to the RVs on stall speed and grass ops, but otherwise, EZs are great airplanes! Peas

[440_Magnum]

Re: The Pond Racer.....Rutan's Watergate

Many aircraft engines do have harmonic balancing schemes in the form of hanging/floating counterweights on the crank.

Understood, and also others (Merlin, for example) achieve the required damping through the accessory drive mechanism. My point was that an automotive type balancer is, in a way, dead weight. Aircraft engines typically have achieved the required torsional damping through other means that provide other useful functions, rather than just hanging an elastically-coupled weight on the end of the crank. Its not a big deal, mostly it was just a reaction to seeing a generic auto part that I can buy online at Summit Racing associated with an aero engine...

[Stevo]

Re: The Pond Racer.....Rutan's Watergate

Peas, you're an R/Cer right? Well I think this little baby might be right up your alley. And since we are talking about Rutan racers... here's another for the R/Cer's.

[First time Juke]

Re: The Pond Racer.....Rutan's Watergate

A very well know drag reduction specialist did a very comprehensive analysis of the Pond racer and his conclusion was there was no way you could ever get it go much faster because of the poor airframe configuration choices.

Michele

Good, jolly good...then there was no problem. Who is he ?

Perhaps a new kind of twin with car engines could have more ram-air effect don't you think ?

[First time Juke]

Re: The Pond Racer.....Rutan's Watergate

..... you're an R/Cer right?

Holy Crap Stevo,

I checked your pics and I saw this:

http://mishuna.image.pbase.com/v3/18/453118/2/46384690.WebIMG_7589.jpg

Where was this taken at ?

I tought they were all gone.

[Peashooter]

Re: The Pond Racer.....Rutan's Watergate

Peas, you're an R/Cer right? Well I think this little baby might be right up your alley. And since we are talking about Rutan racers... here's another for the R/Cer's.

I have a Multiplex Vari with electric power waiting to be assembled. Having too much fun with R/C gliders at present; thermal duration, dynamic soaring and aero-towing.

[spacegrrrl]

Re: The Pond Racer.....Rutan's Watergate

Good, jolly good...then there was no problem. Who is he ?

Perhaps a new kind of twin with car engines could have more ram-air effect don't you think ?

Dave Lednicer was the person that told me of the CFD analysis of the Pond. I believe he knows his stuff in that regard.

Michele

[AirDOGGe]

Re: The Pond Racer.....Rutan's Watergate

I'm not surprised that the Nissan engines in the Pond Racer "couldn't take the pain"...

I've seen a lot of discussion about using car engines in airplanes, but automotive engines and aircraft engines are far more different then one may believe. It takes much more work than changing a few parts to make a car mill durable enought to withstand the forces that purpose-built aircraft engines have to endure. They need beefier crankshafts and bearings, etc...

I still have my issue of 'Air & Space Smithsonian - July 1997' that has a VERY good article on this topic, titled "Power Struggle: Why car engines won't fly" by Don Sherman. A portion of the article involved the story of Thunder Engines, a company that tried to convert a Can-Am racing V-8 into a 700-800 hp replacement engine for aircraft use.


These engines used a 500 C.I. aluminum V-8 block from General Motors, and in turbocharged form could produce up to 1200 hp. But cars and aircraft produce different enviroments, and with a propeller attached the engines could not maintain any form of durability when they were tuned and rated for anything above 500 horsepower. At one point they spent 2.5 million dollars in research and development over the period of one year, and only increased the engine's lifespan from 7 to 17 hours. This project was shelved in 1987 when funds finally ran out ($10,000,000 was invested by this time).

Orenda eventually took over the project in '94 and developed the Thunder Engine further before putting them on the market as the 'Orenda 600', but in the end these engines didn't have any car-manufacturer parts in them (even the race car parts used in the original couldn't handle the job), and one 'Orenda 600' would cost you $100,000-150,000 dollars in 1990's dollars. This is for a 500-600 horsepower-rated V8 (turbocharged), far less power than would be required for an ulimited racer. I think the engine is no longer available.

Pics of an Orenda V8 mounted in an AeroCommander:

http://www.epi-eng.com/CNV-ac685.htm

If you tuned one of these orendas up for the power necessary for competitive unlimited class speeds (1000+ hp) then it's lifespan can be measured in a handful of hours, if it can survive an entire unlimited race at all. That's a lot of money for an engine that with luck might barely survive race week.

Now this converted race car engine has been in aircraft-conversion development for many, many years and never reached it's original power expectations. How could anyone hope to get 1000 HP from far smaller aircraft-converted Nissan V6s without them detonating like live gernades?

Part of the problem for plane-converted car engines besides having to endure ultra-high power loads for lengthy periods of time is that a car's driveline (driveshaft, axles, transmission and even the tires) tend to absord most of the torsional vibration loads a car encounters, but a propeller can actually amplify the vibratory pulses by "ringing" at the same frequencies of the engine vibrations themselves, which inturn are imparted to the crankshaft. Crankshaft breakage and premature bearing wear is unavoidable without creating new stronger parts from scratch (expensive!).

Converting car engines for air racing duty is simply not a practical job in any sense unless you have tens of millions of dollars to throw away and several years available to do the conversion properly and reliably.

.

[Unregistered]

Re: The Pond Racer.....Rutan's Watergate

As John H has said it has also been hard on me to follow this thread. I worked for Steve and Rick was a friend.
Yes an engine was changed at Mojave on the way to Reno. There was a continuing problem with the heads pressurizing the coolant system. I was never informed of the exact cause, either head gasket or cracks.
Going back to the program ran by Burt Rutan, it seemed to lack leadership. They built a throttle setup that cost like $30k but didn't work. Dick would have arguments with Burt and then cancel a test flight or worse then go on the test flight. He would scream about knobs being the wrong color and cancel another test flight. The tailwheel steering couldn't allow the plane to turn 180 degrees on a 100' wide runway so you would have to skid it to turn. The oil scavenge lines in the engines were not changed when it was turned around to make it an airplane engine. With the breather at the rear of the valve covers it would put out a black cloud when the nose was raised up during climb. On the ground an engine was siezed running on the ground due to lack of oil as it was pumped out the breather. It had many lines running air pressure to run the wastegates. Every time it would send a signal to the turbos the computer would sense a change and send another signal. It would end up chasing itself until the computer would give up and roll the power back to atmospheric. The data output would never show a solid line, it always had a wiggle or worse to it.
When I worked on it we made many changes. I made a navy style locking tailwheel setup. There were some car racing people getting involved. Randy Scoville was one. The oil scavenge lines were redone to pick up at the rear of the sump rather than front. That combined with the breathers being moved up front made the oil pumping out the breathers a thing of the past. Some engine lines were reconfigured so the computer had a dedicated MP sense line and that got the engines running smooth. At Reno Rick made the comment that the PR was running smoother than his T-33. That was a 1st in nearly 3 yrs of flying it. The computer was moved aft of the radiator from the engine area previously. It sat in the boom.
The A-10P fuel was made by VP Racing Fuels. It was a doctored AV gas blend and was the most nausating smelling stuff. When the fuel line let go in flight or whatever put the fuel in the cockpit Rick had to undo his O2 mask as the regulator was on the floor and he had to suck up the stuff if he was on normal. That made him undo the mask on the l/h side, unusual as that broke the mic connection but he would have been flying with the right hand.
Steve had the task of proving that something could be made of the PR. Ealier in the year a bunch of testing was done, they stopped and were going to retire it. Then it was brought back out, there were car racing people getting involved and some new dyno work was done. The program came back to life. It was my understanding that a decision was made to gut the plane and start over. All the lines inside were s/s flex lines, not really needed for MP and such. It was a mess of speghetti of lines and wires. All being very heavy. The brakes were poor. Landing gear was wearing out. The thing needed to be gone thru. A decision was made to skip reno and go thru it and prep it for the future. Another change came along and they wanted to go and make an appearance to support the air races. So we went to reno.
The end result is what has been talked about here. The PR did have some more potential. It had been a mis-managed project with deep pockets early on. Many issues that had bothered the plane for years had been resolved. New people were involved and it had a brighter future than what many have said here. Would it have conquered the gold? Probably not. But I think it would have ushered in some changes in this sport.
Rich P

[First time Juke]

Re: The Pond Racer.....Rutan's Watergate

Airdogge,

Thanks for a very thorough research on autoengines on aeroplanes.

I still go to Westland Whirlwind with two 885 hp engines..it carried 4 x 20 mm cannons, ammo etc.

A really small V-8 based racer with 500 hp each and 700 hp when NOS used could still beat the unlimiteds if the power to weight ratio and induced drag where in a right composition...I assume. At least it could look cool...and making it a tandem seater !!?

Whirlwind had 45 feet span ( small ) but I suggest a racer at ca. 23 feet span. 3-5 feet shorter than a Pond.

Wessie info:

http://www.military.cz/british/air/war/fighter/whirlwind/whirlwind_en.htm

Any comments welcome.

PS: I use new drug for my backpain...so the emoticons are now better.

[AirDOGGe]

Re: The Pond Racer.....Rutan's Watergate

Here's is a link to the issue of Air & Space that features the 'Power Struggle' article I mentioned, but the web page does not say whether one can purchase back issues or not. My copy has a torn cover but is still intact (I can be rough on my reading materials

http://www.airandspacemagazine.com/ASM/Mag/Index/1997/DJ/Contents.html

[daveflyshi]

Re: The Pond Racer.....Rutan's Watergate

I have to pipe in just a bit here. Michele, you are just a bit off on your comparison of the longs and varis to any other airplanes. Just look at Claus Savier (I know I probably spelled it wrong). I mean, how many years has he raced in the sport class? Yeah he may run further back than a legacy, but what is the displacement on his engine? What 1/5 of a legacy?

The Long and Vari were designed to cruise. They were supposed to go relative fast on small displacement and get you to your destination. Peas said that he went non stop from CVG to LAL. I don't have the numbers in front of me, but I am guessing about 750-800 nm. And, he arrived with 18 gallons in reserve. I would guess at go for high speed as he admitted he was, he was burning about 10 gallons per hour. That means that he could have just about made it to Cuba. I don't ever recall hearing an RV-4 having an 800 nm range with an 1.5 hour reserve. And, I think he said that he was doing a little over 200 mph. That is what the RV-4 was doing on a bigger engine, and about the same payload.

Now, has Rutan ever had a bad design. I am sure the answer is yes. However, he has a history of creating purpose built aircraft that do exactly what they were designed to do. He probably has others which did not meet expectation. But how many airplanes has he designed? I am guessing well over 50. So a few that did not live up to his expectations are probably ok in the grand scheme of things.

I will not speak to the the design of the Pond. I have a friend who was on the crew, and I have heard a lot more stories than have been told here. I have my own opinions on it. However, Comparing the Long and Vari to the Glassair's, RV's, and Lancair's, is like comparing the Honda Insight to a Hummer at the gas pump when the fuel prices are $2.85 a gallon. What specifically do you want to compare between each specific design?

dave

[First time Juke]

Re: The Pond Racer.....Rutan's Watergate

What I don't understand about Rutan is that he seems to go out of his way to pick non-standard configurations when there is no immediate advantage to the selection. Again, compare a Longeze and and RV-4 head to head and the RV wins hands down.

I understand how you can become focused on non-conventional aircraft configurations....In a very real way Darwinian forces are why almost every aiplane you see today has the same basic configuration.

Michele

Michele,

As an architect I see same trends and styles as in aviation.
Traditional vernacular architecture holds it own. New modern functionalistic houses sell too, but to make houses without overhanging roofs and using enermous glasswindows is almost insane in my country in the north. Energy efficiency is far from perfect and windows are exposed to rain and snow.

Like in a pusher configuration..it looks mighty cool and sometimes it is easier to build than a traditional ( tractor layout ), but there are some drawbacks like the prop can be damaged by gravel etc.

Still you cannot say for sure which is better.
One has to go for what he / she thinks is the best.
Charles Lindberg was intrigued by the " Flying Pancake ". Who doesn't like pancakes ?


best regards,

Juke T


PS: In Pond Racer the exhaust stacks on top are pointing only like 30 degree rearwards..how come...turning them to point 100% behind would have increased the speed at least 4 mph. Making them shorter another 2 mph. Were they too hot for glassfibre ?
Loosing about 400 kilos of thrust because non-ram-air scoop..adds to about 40 mph loss in speed. Along with your claims of intersecting surfaces maybe 20 mph more. Let's see if we have 440 mph to start with ( I recall this was the top speed with methanol ) then adding 4+2+40+20 mph we have 506 mph. We are still 22 mph short of the Bear record.
No worry if the Falconers do let's say 850 hp:s per engine we have 700 hp:s more than a Pond Racer...I think in a small racer 700 horses will do a lot..even 300 more horses could do it ( 22 mph gap ).

For everyone.....this is pure speculation by a layman.

[51fixer]

Re: The Pond Racer.....Rutan's Watergate

Juke wrote:
PS: In Pond Racer the exhaust stacks on top are pointing only like 30 degree rearwards..how come...turning them to point 100% behind would have increased the speed at least 4 mph. Making them shorter another 2 mph. Were they too hot for glassfibre ?

The exhaust on the PR had twin turbos, each head fed a turbo and so the twin exhaust pipes. By the time the hot gases come out they have lost a lot of punch, there is some thrust but I was told by Bruce Boland that it wasn't significant.
The top of the boom aft of the engine had a stainless steel sheet to act as a heat shield. Remember that metal will expand with heat but composites don't as I was told while working on it. The carbon fiber lay up in that area used an epoxy and materials that would hold up to heat better than most composite materials but still would not hold up to that kind of heat.
When the engines were moved forward 6-8" that helped to reduce the heat up there.
Rich P

[First time Juke]

Re: The Pond Racer.....Rutan's Watergate

Thanks Rich,


I really do appreciate a comment from a crew mechanic.

I agree the turbo exhausts possibly only would have gained 1 mph more, but placing the stacks behind one another could have given ( along with being shorter ) 4-5 mph more. Insignificant when going after Bear record for sure. What was the role of Bruce Boland in the PR team anyway ?

Was the highest speed ever recorded by PR on a flyby around 440 mph ?

How did the 6-8 inches change forward of the engines affect the flying caracteristics. Did Rick ever comment on that ?

Were the engines performing better or worse...using methanol or A-10P fuel ?

Previously you also said all the wires ( ie the wires were very heavy ) made the AC heavy. How much do you estimate PR weighed empty ?


best regards,

Juke T