What's up with PM?

[planecrazy2]

Anyone know why Ron B. can't get PM moving any faster? I have loved the Griffon powered ships for years and keep waiting for PM to "get up on step" but....

[DWYER]

Re: What's up with PM?

Probably gotta shove the throttle forward a little more.....j/k..

[Griffon58]

Re: What's up with PM?

There is a lot to think about here.

The plane has never really had a dedicated program or cheif like "kerch" to look her over and find places and parts that slow her down. She is one of the most visually exciting racers out there, and is not really a part of a win at all costs budget. The Griffon package is a bit of a disadvantage compared to what is happening on the Merlin and R-3350 front as well, considering the Griffon has not had the development and or parts supply the Merlins have. (for racing) Regardless the aircraft is one of the only Griffon powered aircraft in the USA, and is a thrilling sight on start, as well as a distinctive sound around the pylons.

I hope the aircraft continues to run for many years as it is rather than sacrificing its unique shape and sound for contention at the top.

[planecrazy2]

Re: What's up with PM?

All noted on your comments regarding PM Griffon 58.

I think your correct. It does take a dedicated "program" and the coin to back it up to make these very complicated aircraft perform up to their potential.

I have been fortunate to witness all four of the Griffon powered birds race over the years. Seen the highs and lows of these seriously modified airframes.

Thanks.

[Bill Marsh]

Re: What's up with PM?

skip

The CR prop and griffon powered p51 species
Years ago (correction on who said what welcome) ?? did skip holm make the statement that either precious metal or ashley 2 .... "was a 450 mph airplane"


feedback please

DOES THE WAYS JUSTIFY = THE MEANS.... with all the extra; weight, mass, drag, area when it comes to the alternative of a sleeker, lighter RR v12 with a four bladed prop.

Or is it a time, $$$ issue to mature the PM airplane

Bmarsh

[Sven42]

Re: What's up with PM?

One of the reasons could be that there has been many years of racing Merlins in more than just airplanes. Unlimited hydros used to use them, so there had to be a lot of tricks learned through the years with that motor. The Griffon has had no such racing history and from what I've read, Rolls Royce put more effort in to developing the Merlin and it recieved all of the good supercharger bits first. Consider also that the Griffon w/ counter rotating props has to weigh quite a bit more than the typical Mustang power plant.

This is a similar situation to the R-4360 vs. the 3350. The big one was out performed by the smaller one many times though the developement stages. Every time the 4360 posted a dyno number, the 3350 team boosted the MAP and showed them up.

Steve

[51fixer]

Re: What's up with PM?

One of the reasons could be that there has been many years of racing Merlins in more than just airplanes. Unlimited hydros used to use them, so there had to be a lot of tricks learned through the years with that motor. The Griffon has had no such racing history and from what I've read, Rolls Royce put more effort in to developing the Merlin and it recieved all of the good supercharger bits first. Consider also that the Griffon w/ counter rotating props has to weigh quite a bit more than the typical Mustang power plant.

This is a similar situation to the R-4360 vs. the 3350. The big one was out performed by the smaller one many times though the developement stages. Every time the 4360 posted a dyno number, the 3350 team boosted the MAP and showed them up.

Steve

Griffons were used in hydroplane racing.
One thing that the Griffon lacked was the room in the crankcase to weld on countweights on the crankshaft. In the past that was commonly done by Z and others on Merlins. The improved rods such as Allison rods in Merlins allow the use of very high MP. These things make it so the Griffon just can't take extreme MP. !30" in a Merlin beats 80" in a Griffon. Many of the Griffons that have been run hard have ended up in Griffon Gulch.
Remeber there are many different versions of the Griffon that were built. They were not built in the numbers as the Merlin was. Some of the more desireable models are pretty rare. The RB-51 engine composed of different model parts. This is highlighted in Pete Law's article mentioned recently in another thread.
Rich

[440_Magnum]

Re: What's up with PM?

This is a similar situation to the R-4360 vs. the 3350. The big one was out performed by the smaller one many times though the developement stages. Every time the 4360 posted a dyno number, the 3350 team boosted the MAP and showed them up.

Steve

I don't know if you're referring to the 3350 and 4360 in racing, or in stock development. I pretty much agree with you for racing configurations. Dreadnought is about as "hot" a 4360 as there's been, and according interviews with Brian Sanders its major tweak is a relatively simple modification (factory modification for certain applications, actually) that eliminates a clutch in the blower drive and makes it a single speed drive capable of more boost at lower altitude. They've also done a lot of detail work including far better oil control and cam-ground pistons, but nothing like what has been done to Merlins, and really nothing like what has been done in terms of mixing power, nose case, and blower sections of the 3350 by the Bear, Critical Mass, and 232. So in one way I agree, the racing 3350 has stayed ahead in ultimate power. But thinking of it another way, Dread's 4360 is no more exotic than the 3350s in the Sea Furies like 911, Argonaut, Spirit of Texas, and Fury, and yet it runs significantly faster than they do.

But in stock development, I disagree. It required a turbo-compound 3350 to match the horsepower of a simple (relatively speaking) twin-turbo 4360(*). Not to mention that the installed weight of a 3350 TC was within a few percent of a 4360 of equal power. P&W actually did some work toward a turbo-compound 4360 that would have likely suprassed the 3350TC by several hundred horses, but luckily for P&W they realized that there was no future for piston engines of that size and put more effort into making the J-57 better. Wright, on the other hand, seemed to think the 3350 would dominate the market forever and rode it right into extinction by failing to develop a turbine powerplant comparable to P&W's J-57 or GE's J-79

(*) Somewhere long ago I read a really great paper on the twin turbo system that the B-36 used. Back in those days, the flight engineer really earned his keep, regulating boost and RPM and controlling which of the turbos was used.... on six 4360s at once. In cruise mode at high altitude, each engine operated on a single turbo at low crankshaft rpm and high manifold pressure for efficiency. That resulted in a farily modest mass-flow through the engine, and a hiccup could cause the turbo RPM to drop slightly, which in turn would drop the manifold pressure, which dropped mass flow, which further slowed the turbo leading to "boost collapse" and spiraling power output that could only be stopped by incereasing the crankshaft RPM to spool the turbo back up. Not quite as dramatic as an SR-71 "losing the spike," but still pretty interesting.


Finally, getting back to Griffons- from all the reading I've done over the years, there are only two things wrong with the Griffon for air racing. One is that there aren't enough of the variants that can make a lot of boost. The common Shackleton variant just doesn't have the blower section to make it a racer. The second is the lack of a good prop and prop drive combo. I've seen it said that the airfoils of the Shackleton contra-prop are "about as exotic as the wing of a Piper Cub," and I've also read that they are more flexible than is desired, so getting more efficiency out of that prop would pretty much mean starting from scratch. And there's no way to take advantage of something like the Aeroproducts Skyraider props or the various P-51 props with the contra-prop case.

[AAFO_WSagar]

Re: What's up with PM?

Ron is doing a really respectable job of gettng the most he can out of PM with an EXTREMELY limited budget and resources!

Cut the guy and the airframe some slack fellow fans...

PM racing is truly one of the more amazing low buck operations out there..

Ron flies a nice line, gets the most he can out of a pretty stock Griff..

Provides a lot of thrill just seeing the airplane.

Suffice it to say, it's probably a lot easier to ask why he doesn't go faster than it is to actually find the money to make something go faster.

Personally, I don't think the full potential of a Griff powered Mustang has been seen.. yet..

I'd LOVE to see the combination be a winner and something seen on a much larger scale.

Mustangs do sound nice but Griff's have such a sweet low rumble!

Sides that. they make Griffon Girl all.. er.. well.. happy..

[Wilnit]

Re: What's up with PM?

Another thing to think about is that Ron B. simpy doesn't want to push the airplane too much. He could be a conservative racer, and there is nothing wrong with that... How many Griffons are still racing... ONE!!!

I am happy seeing PM on the course, even though it hasn't been in the gold. Ron wants to be there, and some day he probably will be there.

Remember that Ron brought the plane to the Air Races in 2001 (after being in a hanger for, I can't remember how long) and didn't get to race. So, he has been there since and has competed every year since then...

Thank you Ron for bringing an exotic plane to the Air Races, may you have a safe and successful air racing career..............

WRL

[zeke]

Re: What's up with PM?

Regardless the aircraft is one of the only Griffon powered aircraft in the USA, and is a thrilling sight on start, as well as a distinctive sound around the pylons.

Precious Metal being the only Griffion Powered Mustang & Racer currently out there, how many Griffions would still be in use anywhere?

From what I know of there's 2 Shackleton's airworthy & 1 potentially, 3 Firefly's & a few restorations, Maybe about 10 Spitfires with Griffions and the MB 5 replica & of course 1 Mustang. So somewhere around 30-40 motors that might get some use or be airworthy.

Is there any others out there still used for anything else other than aviation, are they still used in Hydro racing?

So there would be Heaps more Merlins flying being in all the Mustangs & most of the Spitfires.

[mayday51]

Re: What's up with PM?

....search this site.....

I think it was Speeddemon who posted some info/facts on the use and mods to the griffons pertaining to unlimited hydo appl.

.....special gears (psru ?)....best combo....

[MRussell]

Re: What's up with PM?

The race announcer said today that PM is using a Griffon lifted directly out of Miss Budweiser when she was switched to turbine power... is this true???

[Mike51]

Re: What's up with PM?

Nothin's up with PM (apart from the occasional deadline cut............)

[chuck]

Re: What's up with PM?

There is already talk of converting it to a guest what?