MA-II Speed Potential

[BellCobraIV]

Re: MA-II Speed Potential

That would be cool! Can a race-prepped Griff prodcue more than a highly tweaked mouse-motor? Or, just assume 3,000 hp either way?

Peashooter,
Ah, therein lies the problem, with a race prepped Griffon of the type that is available in quantity to build a program around, you are limited in "mechanical" boost available, Two stage Griffons are rarer than slow nose R-3350's. The Griffon Supercharger drive was not as advanced as the Merlin Supercharger drive which is really in part a Packard drive licensed by design from Wright. So even though you have 589 extra cubic inches, you can not utilize them as well as the 1650 cubic inches you have with the Merlin, due to the limited amount of boost you can RELIABLY build with the Griffon. Dave Zeuschel had written a really nice letter to Wiley Sanders at the beginning of the Jeannie program outlining the advantages and disadvantages of both engines and in the end the advantages of the Merlin outweighed the disadvantages of the Griffon.

[speeddemon]

Re: MA-II Speed Potential

John, was Carl Friend suggesting the Mustang wing was faster than the Lear? I would think that there was good bit of thought put into the Lear wing retrofit before the trouble was take to do so. Man that would be something if a team were to go through that kind of trouble and not be faster.

As John Slack pointed out, the metal work and craftsmanship on Vendetta was literally second to none. It was an amazing piece of machinery. And John Dilley will tell you that during the testing of Race 19, he saw some amazing 'straight line' numbers, as well as being able to completely outmaneuver a stock Mustang. (His quote was that it flew like a Pitts Special, and that he could literally fly it with two fingers.)

But Dilley will also tell you that the project came about from a literal "Hey, THAT would look cool" kind of encounter with a Lear Jet. It wasn't like they sat down and designed a racer with the optimal wing for racing at Reno. A Lear taxiied up out in front of Fort Wayne Air Service, and Dilley looked out the window and thought that that would make a cool wing for a Reno racer. They ran the numbers and modifications to THAT wing, because that was what they were able to secure.

A lot of the engineer types will tell you that the stock Mustang wing gives a better bite for the shorter Reno course, where you are in a constant turn.

Sure looked cool, though.

[BellCobraIV]

Re: MA-II Speed Potential

Another thing to consider is that the RB used the two-stage Mk57 Griffon, while MAII used the less powerful single-stage MK 74. I know there was a lot of talk in '98-99 that they just weren't getting the power out of the Mk 74 that they had hoped, but there wasn't enough room as far as the airframe would allow 'as is' to utilize the bigger Mk 57.

Brad,
Minus three on the geek points, back to your room until you come up with the correct correlation between Griffon MK numbers and supercharger stages, hint the really cool Griffon was the MK 101, What was different about that? Multiple geek points for a quick answer with no research.

[speeddemon]

Re: MA-II Speed Potential

Brad,
Minus three on the geek points, back to your room until you come up with the correct correlation between Griffon MK numbers and supercharger stages, hint the really cool Griffon was the MK 101, What was different about that? Multiple geek points for a quick answer with no research.

Holy Crap. I DID reverse them, didn't I. How could I do that? Look...in my mind I KNEW the 74 was the two stage and the 57 was the single stage. Actually...I was just TESTING you....yeah, that's it......

Hey Jarrod...you taking notes? I messed up. AGAIN. :-)

[Peashooter]

Re: MA-II Speed Potential

So IF I had the jack and I decided to have Art Teeters and/or Gerry Beck build me a full-race airframe, John and Brad's excellent comments move me toward an H-model fuse, tail and wing -- modestly clipped and with a race canopy and boil-off cooling. But the engine? Hmmm, I'd desire to be reliable at say laps of 470 so I could beat the Buick and lie in wait for the others to break! And still fly home at the end of race week. (Asking too much?) I would plan for sprint laps of 480-490, with a spare engine in the trailer. The trade-offs with a Griff equal in power to a Mouse Motor are somewhat increased reliability and no torque (with a contra-prop), but at the expense of WEIGHT. But then there's the Allison G6... How did they do in the "boats", Brad?

BTW with this thread, I want to honor the memory and vision of Gary Levitz, the efforts and inspiration of Bill Rogers, as well as explore the potential of, to my eye, the prettiest racer to ever take to the pylons.

[speeddemon]

Re: MA-II Speed Potential

But then there's the Allison G6... How did they do in the "boats", Brad?

Up through the mid 1960's, the G6 "aux-stage" Allisons were actually pretty competitive with the Merlins. Bill Stead won the '59 Gold Cup and National Championship in "Maverick" with the G6. Mira Slovak won the '66 Gold Cup and National Championship in "Tahoe Miss" with a modified version of the G6 also.

I think one of the things is the availability of the aux-stage Allison. Just not that many around.

[BellCobraIV]

Re: MA-II Speed Potential

Brad,
Griffon 101,........Waiting.......

[jarrodeu]

Re: MA-II Speed Potential

Hey Jarrod...you taking notes? I messed up. AGAIN. :-)

Are you kidding, I love these posts? Every time there are good posts like yours and the other geeks posts, I print it out and add it to the pile of information I have in my room. The pile is now 3-4 inches high, no kidding. There is probably something wrong with me.

Jarrod

[speeddemon]

Re: MA-II Speed Potential

Brad,
Griffon 101,........Waiting.......

Oh, you were serious?

Well, I don't know a whole lot about it, other than it was the last production model. I think it was used in the late model Spiteful's. Two stage supercharger, and three speeds. Not sure if the piolet' had a gear shift in the cockpit, or what.

Damn clutch.....

[speeddemon]

Re: MA-II Speed Potential

Oh, you were serious?

Well, I don't know a whole lot about it, other than it was the last production model. I think it was used in the late model Spiteful's. Two stage supercharger, and three speeds. Not sure if the piolet' had a gear shift in the cockpit, or what.

Damn clutch.....

Okay, and now that I've ANSWERED, I went and looked it up. The 101 never went into production...but I was right that it was put into a few models of the Spiteful (which was the outgrowth of the Griffon Spit), and had a straight and level speed of 490 mph.

[BellCobraIV]

Re: MA-II Speed Potential

Okay, and now that I've ANSWERED, I went and looked it up. The 101 never went into production...but I was right that it was put into a few models of the Spiteful (which was the outgrowth of the Griffon Spit), and had a straight and level speed of 490 mph.

Back to your original score; But the 101 had a three stage supercharger "Holy MAP! Boostman"

[speeddemon]

Re: MA-II Speed Potential

Back to your original score; But the 101 had a three stage supercharger "Holy MAP! Boostman"

Of course, you probably had to be up in the ionosphere to use that third stage.

I wonder if it would do anything but breathe heavily at 5000 feet.

[Peashooter]

Re: MA-II Speed Potential

The Spiteful is one sexy machine! What might have been...

http://www.supermarine-spitfire.co.uk/the_spiteful.htm

Since the Griffon 101 isn't around, perhaps the IO-12 developer would knock off a RR Crecy for my above mentioned concept plane -- minus the sleeve valves. Hold your ears!

http://www.aafo.com/hangartalk/showthread.php?t=645

[fenceliner01]

Re: MA-II Speed Potential

Armstrong-Siddeley Double Mamba
Gas Turbine Turboprop
Rougly 4000shp
Used in Fairy Gannet ASW A/C

I know this because they have one on display at the Pima Air Museum and I was just thinking about putting a picture of the front end up to see if anyone could identify it.

Too easy. Come up with something hard, or I'll pull the handles too.

Better do it on another thread, tho.

[BellCobraIV]

Re: MA-II Speed Potential

So IF I had the jack and I decided to have Art Teeters and/or Gerry Beck build me a full-race airframe, John and Brad's excellent comments move me toward an H-model fuse, tail and wing -- modestly clipped and with a race canopy and boil-off cooling.

Peashooter,
The concept of starting from scratch with a Mustang racer has been explored, and there are some definate benefits to "building a Mustang" just for the job.