A question about Furias

[440_Magnum]

Re: A question about Furias

Stock TC engines are rated up to 3,700HP with water injection, so... not really

But here's the deceptive thing about the 3350 turbo compound: 900 (give or take) of those horsepower don't come from the failure-prone parts: jugs, pistons, connecting rods, etc. Each of the three exhaust turbines puts about 300 horsepower straight onto the crank through a fluid clutch. In some regards, the TC engine's power section isn't working as hard at 3700 HP to the prop as a non-TC engine at 3600 HP. Of course there's higher exhaust back-pressure and all the associated stress, so its not an easy comparison... but that's kinda the point. Its apples and oranges.

[ChrisMX105]

Re: A question about Furias

But here's the deceptive thing about the 3350 turbo compound: 900 (give or take) of those horsepower don't come from the failure-prone parts: jugs, pistons, connecting rods, etc. Each of the three exhaust turbines puts about 300 horsepower straight onto the crank through a fluid clutch. In some regards, the TC engine's power section isn't working as hard at 3700 HP to the prop as a non-TC engine at 3600 HP. Of course there's higher exhaust back-pressure and all the associated stress, so its not an easy comparison... but that's kinda the point. Its apples and oranges.

Keep in mind too that the turbines were not designed for the G-Loads or turbulence of the course.

[ChrisMX105]

Re: A question about Furias

My point exactly..


In regards to 'drag difference',
What's the weight difference between a race-loaded 232, and 77 ?

The difference between 480 and 490 is nothing... The pilots line can make a 20mph lap difference... So can Weather.

- Joseph

Difference between 480 and 490 is actually significant. Drag rise is exponential and propeller efficiency drops at an exponential rate.

Weight difference is probably 1500-2000 lbs

[RichH]

Re: A question about Furias

No one runs a turbo compound 3350 right now. I'm comparing what is on the course and available.

Michael

Well yes and no... all I am saying is that the engine on 232 *is* indeed at its heart a TC engine, just that the TC bits have been removed. So, the parts involved have been designed around that kind of *output*. Probably better to say it's running beyond its stock RPM and MAP limits to get there...

[RichH]

Re: A question about Furias

Just guessing here:

a 3350 -26W published weight is around 2700 pounds,

Figure the engine on 232 will be a bit heavier than a -26W since it retains the full intermediate section of the Turbo Compound variant plus the bigger blower section which adds quite a bit of length to the @$$ end...

[Lon Moer]

Re: A question about Furias

Sanders Aeronautics - Argonaut

Its Bristol Centaurus engine was replaced with a Wright R-3350-26WD radial engine, driving a Douglas Skyraider propeller, and first flew after restoration on July 30, 1994. It was named "Argonaut" and assigned race number 114.

In the past, numerous people have asked about the possibility of installing the Pratt & Whitney R-2800, well known for its outstanding record of dependability. After doing a comparison between the two engines we decided to convert “Argonaut” to an R-2800 CB16/CB3.

Conversion was scheduled to start after Reno, but after the word got out, the interest was to the point that we started sooner. When comparing the two engines, it can be seen that the numbers are fairly close and the dependability becomes the overriding factor in converting to the R-2800.

<>

On April 19, 2011 Dennis Sanders took Argonaut on a successful 20 minute first flight with the new Pratt & Whitney R-2800 CB3. Argonaut was inspected after the flight and Brian Sanders then flew Argonaut on it's second flight later that afternoon. Both reported that the R-2800 CB3 engine pulled as hard as the old R-3350 and the aircraft handled very well..

R-2800 ?
R-3350 ?
R-4360 ?

[Idaho_cowpony]

Re: A question about Furias

I think my choices for big radial racing birds would be:

2800
4360
3350

Why?

Price.

Power to Weight.

Reliability.

Sound.

etc., etc...

Maybe I'm just a PW guy ?

haha

- Joseph

[L.E.D.]

Re: A question about Furias

Sanders Aeronautics - Argonaut


R-2800 ?
R-3350 ?
R-4360 ?

Argonaut has had the R-2800 since 2011, I believe.

[GRNDP51]

Re: A question about Furias

I think my choices for big radial racing birds would be:

2800
4360
3350

Why?

Price.

Power to Weight.

Reliability.

Sound.

etc., etc...

Maybe I'm just a PW guy ?

haha

- Joseph

BMW 803

[Lon Moer]

Re: A question about Furias

Originally Posted by lon moer View Post
Sanders Aeronautics - Argonaut


R-2800 ?
R-3350 ?
R-4360 ?

Argonaut has had the R-2800 since 2011, I believe.

My point was that we have one source saying the 3350 is 'better' than the 4360 and another source saying the 2800 is 'better' than the 3350, so is the 2800 'better' than the 4360??

[L.E.D.]

Re: A question about Furias

Ah, I misunderstood.

My impression is that for the Sanders' mission (restoring Sea Furies) the R2800 is the better choice. I don't think they're proposing R2800 Sea Furies as the all-out racer solution.

[440_Magnum]

Re: A question about Furias

Keep in mind too that the turbines were not designed for the G-Loads or turbulence of the course.

Definitely true, nor were they really designed to do their best at relatively low altitude. Aircraft that used 3350-TC engines were (and last time I saw anything published still ARE) the most fuel-efficient airliners ever. I don't think anything has yet quite equaled the specific fuel efficiency of a DC-7C. But they did it at high altitude after switching the supercharger drive to "high," bringing the MP up and the propeller RPM way down so that the turbines were seeing high exhaust flow and pressure, and exhausting into a low atmospheric pressure environment while flying straight and level for many hours. Its hard to think of anything more different from air racing.

As for 232's engine, I know that it retained the TC accessory section and fuel injection under Mike Brown, but isn't that all gone now? (jokes about the whole engine being gone: too mean!)

[440_Magnum]

Re: A question about Furias

Ah, I misunderstood.

My impression is that for the Sanders' mission (restoring Sea Furies) the R2800 is the better choice. I don't think they're proposing R2800 Sea Furies as the all-out racer solution.

I think Argonaut flies to a lot of events throughout the year promoting the Sanders smoke generator business. Its a working aircraft, not just a racer so reliability is certainly important for them. The results clearly show that its slower with the 2800 than it was with a 3350, but then I honestly don't think that engine is an all-out racing 2800, either, so whether or not a 2800 could really match the 3350 is something of an open question. The fact that Rare Bear took away Conquest 1's speed record holds a clue- 550 cubic inches isn't a trivial handicap to overcome. But on the other hand Rare Bear took the record after a lot more years of development after development on Conquest 1 stopped. The 2800 is famously reliable and there are articles from the 40s that indicate it was tested to 4360-like power levels by P&W at one point. But a test cell is different than actual flying.

So if its so good, why hasn't 86 won yet? Nobody's talked about that for a while- what more does the little Yak need to actually run with Strega and Voodoo? My guess: a better propeller. It can't physically mount a large-diameter prop, so I don't know what the solution would be. Better airfoils on the blades? A 5th blade comes to mind, but I bet there's nothing remotely close to "off the shelf" that would work.

[ChrisMX105]

Re: A question about Furias

Conquest 1: 1969 483 MPH
Red Baron: 1979 499 MPH
Rare Bear: 1989 528 MPH

So technically RBear beat RBaron not Conquest 1

Czech Mate needs a wing that didn't have the airfoil borrowed from a Piper Cherokee.

[RichH]

Re: A question about Furias

Czech Mate needs a wing that didn't have the airfoil borrowed from a Piper Cherokee.

And longer legs. Not enough room to swing a big enough prop...