# Making an "obsolete" fighter into an unlimited racer !

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#### Riggerrob

##### Well-Known Member
Recently, an incomplete Sport Class twin - designed by our Orion - was offered for sale. It was powered by a pair of production, horizontally-opposed Continentals or Lycomings.
If you want to win Sport Class, start with the biggest Lycoming available: IO-720 with 8 cylinders.
Much of the expertise seems to be in learning how much you can over-boost (turbo-charger or super-charger) a production engine before it breaks.

Oh! And the latest fashion is Schumann wings with straight trailing edges and elliptically-curved leading edges. To maintain enough laminar flow, they need to be laid up in precision female molds and sanded for hundreds or thousands of hours.

#### Riggerrob

##### Well-Known Member
Dear rhbelter,
I am skeptical about long drive shafts.
Yes, they help balance airplanes.
Yes, they help finesse ratios and streamlining, but I worry about shafts flexing during high-G pylon turns.
The perfect racer is light with as few parts as possible.
I just know how to build it?????

#### Andy_RR

##### Well-Known Member
Why worry about things when you can get your calculator out and figure out a solution? Otherwise known as engineering...

#### TarDevil

##### Well-Known Member
Making a purpose built racing airframe, using modern materials and engineering, and modern aerodynamic analysis methods, could easily yield a 500 MPH racer.
Such as ...

(I have a fondness for a particular airframe... a sharp eye might note!)

#### Victor Bravo

##### Well-Known Member
No, smaller than a Sea Fury.

#### Tiger Tim

##### Well-Known Member
Such as ...

(I have a fondness for a particular airframe... a sharp eye might note!)
Reminds me of the three unfinished unlimiteds; Shockwave, American Spirit, and Wildfire.

#### lr27

##### Well-Known Member
If it's smaller than a Sea Fury, won't it need a pilot with a small head?

#### TerryM76

##### Well-Known Member
HBA Supporter
And a huge wallet.

#### Victor Bravo

##### Well-Known Member
My comments were originally based on something shaped like AJ Smith's AJ-2 racer, but with retractable gear and scaled up to the point where a 3000HP hopped up R-2800 would not tear it completely apart.

#### Voidhawk9

##### Well-Known Member
HBA Supporter
Slicked up Radial Rocket? Nice. Big fan of the P85 myself.

#### Speedboat100

##### Well-Known Member
Later versions of the Buffalo were heavier too.

Yes...but not sufficiently powered..as the engine was the same..as in our modest model 239. Just more tweaked. Lighter plane was propably better against the I-15 and I-16 fighters.

Our "best" fighter was Fiat G.50..with 44/1 kill ratio...Brewster second with 33/1 kill ratio and third Me-109 with 24/1 kill ratio. This tells about the enemys advancing skills and also the lend-lease act started to show in the soviet material resources.

#### Speedboat100

##### Well-Known Member
Slicked up Radial Rocket? Nice. Big fan of the P85 myself.

This is cool:

#### Speedboat100

##### Well-Known Member
Japanese "wunderwaffe" was the long awaited Raiden J2M3 : https://en.wikipedia.org/wiki/Mitsubishi_J2M?fbclid=IwAR1QhmMkAz8upi-zaCruBIr0V2w5NzXpoT-81CVQalyM-l1nLY2mRA61QTM

It lacked turbocharger and still managed to fly 671 km/h.

Two captured J2Ms were U.S. Technical Air Intelligence Command (TAIC) tested using 92 octane fuel plus methanol, with the J2M2 (Jack11) achieving a speed of 655 km/h (407 mph) at 5,520 m (17,400 ft),[3] and J2M3 (Jack21) achieving a speed of 671 km/h (417 mph) at 4,980 m (16,600 ft).[3]

#### TarDevil

##### Well-Known Member
Slicked up Radial Rocket? Nice. Big fan of the P85 myself.
Bingo.
My vision of the P85 on steroids with that 2800 up front.

I hope Jeff doesn't mind me daydreaming with that gorgeous bird of his.

#### Speedboat100

##### Well-Known Member
2020-Feb 4th

Ahoy, HomeBuiltAirplanes,

Dark-of-the-night thoughts ::::

Reno Racers: Very high level development, but innovation ????

Sheeessh !!! And youse-guys want to build just another almost-the-same ‘critter’ as everyone else is flying ???? !!!!

It comes to my mind that the only significant innovative ‘things’ which I have seen there are vapor phase cooling, and (years ago), the clean-sheet Pond Racer.

At Reno, I was talking with an Aerothermodynamicist, (my thesis field) whose name, I no longer recall, but his was on more than half of the landing gear doors present.

My question was about vapor phase cooling endurance, and he noted that at low power, it was pretty good, with the P51 – so rigged -- having flown from Portland to Van Nuys.

The Pond Racer sounded like an immense window fan. He remarked that they were going to need to automate a lot more things, because the pilot workload with cooling doors and spray nozzles and all else was overwhelming. Unfortunately, no longer needed.

Sports Racers:

The Reno Go-Fast Sports Racer Rules: … ‘Aircraft are to be powered by an internal combustion engine or engines totaling no more than 1000 cu in.’

I’ve neither seen, nor heard any talk about a pair of 495 cu/in seriously hot engines installed in an appropriate --- say a tandem engine / tilt-wing / extension shaft airplane.

Of course, the extension shaft is no casual thing. A comprehensive dynamic analysis is in order, along with appropriately measured results. The development of such may well be made easier by using a clutch to de-couple the shaft during start, and up to some certain rpm.

BTW, a seriously dangerous soul is one with a shop full of high tech tools who can craft a PSRU, but is ‘unlettered’ in his ability to technically analyze the dynamics of his ‘creation’, nor is he capable of measuring the result.

Tandem engines were figured out by Bugatti 80 years ago. Too bad that the beautiful replica airplane did not have a proper dynamic shaft analysis / measurement. What I read about the loss was ‘clutch failure’. I’ll bet that a lot of unplanned for torsional dynamics were very involved with that clutch failure.

The wetted surface of such an airplane could be about the same as a single engine critter, and with twice the HP, I suggest that a well-done airplane like that would absolutely rule the Sport Racers, and scare the crap out of the unlimited guys.

WHY is such an airplane not seen??? I cannot be the only guy to have had such ideas.

I believe that there is plenty of \$ in the hands of the Reno Racers to do such. ??????

Enjoy /s/ Bob

Hi Bob !

I have studied fluid dynamics and fluid mechanics in local university since 2019, but I am an architect by profession. I tinker with a new mechanism on a H-Darrieus wind turbine.

I see the potential in this HUMU as there is a public demand to show an "indigenous" historical fighter in our air shows.....a Brewster as a home product is the best bet..as the Myrsky ( Storm ) and Pyörremyrsky ( Taifun ) were truly just prototypes with parts falling off while flying.

rgds,

Juke

#### Speedboat100

##### Well-Known Member
Bingo.
My vision of the P85 on steroids with that 2800 up front.

I hope Jeff doesn't mind me daydreaming with that gorgeous bird of his.

No wonder..this is the "small cousin" of the Bearcat!

#### Speedboat100

##### Well-Known Member
Such as ...

(I have a fondness for a particular airframe... a sharp eye might note!)

Hughes H-1 racer ?

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