Upper limit on R-3350 in horsepower.

[Unregistered]

AAFO members,

In doing research on waste gas (exhaust ) for internal combustion piston engines, I have found that the Cyclone 3350 has a long term success in recapturing exhaust energy.

Apparently the "Neptune?" navy plane stats. states that the latest version has a h.p. rating of over 4000 horse power (i assume this is at take off AND a motor that was released into service and not some project test bed experminent.

MY QUESTION IS,
If this is true, what is the accepted (swag) on the #77 Bearcat power capability (seems to be that most aggeressively modified 3350 out there today.)

Im sure it is running water injection, but is it the turbo-compound, alcohol or NOx?

Thanks.

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[matt]

Re: Upper limit on R-3350 in horsepower.

in the early '90's the bear produced as much as 4200 hp, but these days i don't think it produces quite so much.

there are no prt's on the bear, but it does use water methanol injection and as far as i know doesn't use no2.

[440_Magnum]

Re: Upper limit on R-3350 in horsepower.

AAFO members,


MY QUESTION IS,
If this is true, what is the accepted (swag) on the #77 Bearcat power capability (seems to be that most aggeressively modified 3350 out there today.)

Im sure it is running water injection, but is it the turbo-compound, alcohol or NOx?

Thanks.

**moderator note: Please register so your posts will show without review. It's free. It's easy!**

The Bear's R-3350 does not use power recovery turbines, nor does the R-3350 in September Fury, although both of those race engines are derived (at least in part) from turbo-compound R-3350s. So was the powerplant in Critical Mass, which if I recall correctly was often called a "clone" of the engine in the Bear. September Fury is a somewhat different approach and (unless it has been converted- a lot less info leaks out of the Fury camp than used to ) is fuel injected rather than carbureted. The only A/C I can think of that raced with PRTs in place was a 3350-powered Yak called Mr. Awesome, but it was never particularly successful. Apparently the prevailing wisdom is that PRTs don't fare well in the high-G, low-altitude environment of air racing. The most successful application of PRTs was in airliners like the DC-7C and Constellation/Starliner, where they were most effective at increasing efficiency in high-altitude cruise. I don't know if its something specific to the Wright 3350 implementation of PRTs that makes them unsuited to racing, or if its more general. I do know that the Wright PRTs were coupled to the crankshaft via fluid clutches fed with engine oil, and I can certainly see where momentary interruptions in oil flow due to maneuvering and G-loading would be a Really Bad Thing (tm), but that's more speculation on my part than anything else.

[MRussell]

Re: Upper limit on R-3350 in horsepower.

What is the difference between a prt and a turbocharger???

[Propellerhead]

Re: Upper limit on R-3350 in horsepower.

What is the difference between a prt and a turbocharger???

The PRT takes exhaust energy via a turbine (or in the case of the 3350, three turbines - IIRC) and puts it back into the crankshaft. A turbocharger takes exhaust energy and uses it to drive a supercharger on the induction side.

I'm not sure Mr. Awesome flew long enough for the PRT R-3350 to be a problem. There was that bullet induced oil cooler issue, if I recall. Maybe the two Randy's can weigh in on this one.

[440_Magnum]

Re: Upper limit on R-3350 in horsepower.

What is the difference between a prt and a turbocharger???

A power recovery turbine or "turbo-compounding" captures waste energy in the exhaust stream and uses it to directly turn the crankshaft. Typically, there is also a supercharger driven by the crankshaft in these engines, and one could claim that the PRTs drive the supercharger with as much validity as one could claim that they drive the propeller. A turbocharger captures waste exhaust energy and uses it *solely* to compress the intake charge by spinning a compressor on the same shaft as the exhaust gas turbine- there's direct no coupling to the cranshaft at all. But ultimately, the recovered power still gets to the crankshaft and to the driven load.

[TOR_DP]

Re: Upper limit on R-3350 in horsepower.

Just think about the potential goodness in Race 57's 4350!

Mmmmmm I get all swooney thinking about it.

[440_Magnum]

Re: Upper limit on R-3350 in horsepower.

JMHO.. but I don't think we'll get to see all of the potential goodness from this motor this year (or in the future). Just too valuable/rare (as if the others aren't ??) a bird to push it too hard. I predict he'll win Silver and then decline bump up Still gonna be awesome to see a Corsair rounding the pylons again...

Yep. The most finely-tuned R4360 rounding the pylons will continue to be Dreadnought, at least for the forseeable future.

[Propellerhead]

Re: Upper limit on R-3350 in horsepower.

Yep. The most finely-tuned R4360 rounding the pylons will continue to be Dreadnought, at least for the forseeable future.

Yup, the Buick will run - as usual - at a VERY dependable 455 mph.

Tim Adams and I almost got flattened by Race#8 last year out in the valley during qualifying (50-60 ft overhead). She ran wide after calling for the clock. It was... concussive.

About all I could do is shout things along the lines of that TV announcer in the UK who got buzzed by the Spitfire. After getting stomped by 4,000hp at 450mph it's impossible to be articulate.

[Blue Foam]

Re: Upper limit on R-3350 in horsepower.

Interesting side note was that the chief test engineer on the R-2800 pushed his engines to over 5200 HP for hours while his co-workers were trying to develop the 4360. While this was on brand-new, wartime-budget-be-damned parts, it makes me wonder if a little modern technology could create a 4000 HP R-2800 with enough life for a dozen races.

Red, what would a Yak-3 do with 4000 ponies?

[Peashooter]

Re: Upper limit on R-3350 in horsepower.

5,200? Was it from boost, rpms or both? Sounds good if you can keep it cool and the prop tips sub-sonic. Time to resurrect the R-2800 'Stang!

[Apteryx]

Re: Upper limit on R-3350 in horsepower.

Hey Eric-
How about adding the (R-2800)-29 case used in the XP-56, for counter rotating blades.
That would make for an interesting beast.

Paul

[AAFO_WSagar]

Re: Upper limit on R-3350 in horsepower.

Maybe Wayne could get him a personal invite to the ToR opening.....

Well I did chat with son David a couple weeks ago and he's aware of the TOR project but was pretty busy promoting his own movie right now "Flyboys"..

I hope to speak with him again prior to the deadline for promotion of their movie (release day if I'm not mistaken)

I seriously doubt you'd ever see them (Ellisons) involved with air racing but now Movies.. that's another story!

Looking forward to both theirs and ours! If Flyboys does well, it should help sell TOR to the distro houses....

<crosses fingers>

[G. van Dyk]

Re: Upper limit on R-3350 in horsepower.

Interesting side note was that the chief test engineer on the R-2800 pushed his engines to over 5200 HP for hours while his co-workers were trying to develop the 4360. While this was on brand-new, wartime-budget-be-damned parts, it makes me wonder if a little modern technology could create a 4000 HP R-2800 with enough life for a dozen races.

5,200? Was it from boost, rpms or both? Sounds good if you can keep it cool and the prop tips sub-sonic. Time to resurrect the R-2800 'Stang!

Here is a good little Biography on Frank Walker, the P&W engineer who did a lot of development testing on the R-2800, including the little contest with the R-4360 team.

http://www.enginehistory.org/Frank%20WalkerWeb1.pdf#search=%22r-2800%20engineer%22

Hope you all enjoy it as much as I did.

Gerry

[AirDOGGe]

Re: Upper limit on R-3350 in horsepower.

Thanks for the link, Gerry. I'm really looking forward to reading it.