I have the taste of Metal in my mouth!!!

[Propellerhead]

Re: I have the taste of Metal in my mouth!!!

The prop configuration is the easiest part of the conversion. The physical size of the engine/mount/firewall/cowling etc... is the tough part.

Not to mention new cooling requirements...

Rob

[AAFO_WSagar]

Re: I have the taste of Metal in my mouth!!!

Not to mention new cooling requirements...

Rob

I'm not totally sure on that one.. I believe MAII ran with Georgia Mae's scoop, originally... Seems that part of the combination is fairly "stock" Mustang.

Sure wish BR visited here!

[2101]

Re: I have the taste of Metal in my mouth!!!

Dare to be different.How about a griffon Fury?Those slab sides sure would look nice with an inline in front.Plenty of clearance for a prop that would be determined by the reduction gears.Boil off maybe?Should come down the chute like an ape.

[AAFO_WSagar]

Re: I have the taste of Metal in my mouth!!!

Dare to be different.How about a griffon Fury?Those slab sides sure would look nice with an inline in front.Plenty of clearance for a prop that would be determined by the reduction gears.Boil off maybe?Should come down the chute like an ape.

Ahh... I know who you are and KNOW you know of what you speak....

Jogging my memory here.. wasn't the Fury type originally going to run with a Griffon or some other Rolls vairant but they went with the Bristol instead.. hence the somewhat round (nose) to slab side transition??

Now, that would be a KOOL airplane!

Hit any sprinkler heads lately???

[Blue Foam]

Re: I have the taste of Metal in my mouth!!!

The prop configuration is the easiest part of the conversion. The physical size of the engine/mount/firewall/cowling etc... is the tough part.

Yes, and it's all complicated by the fact that the Merlin is mounted to built-up beams extending from monocoque structure. My own thought would be to chop everything at the firewall, build up engine mount points backed by longerons, and go with a space frame mount. Copying the mount from the MB-5 would be a good start. LOTS of details to work out and it would be a heck of an expensive kit. The balance of the aircraft would change dramatically.

I'd keep the counter-rotating. There are big advantages, and the implementation on the RB, MAII, and PM missed things that would buy 50 to 100 mph. Don't fault the technology for lack of development. If anyone thinks CR isn't a great idea, look at the TSFC of the Russians. Their engines are far less efficient than the western equivalent, yet the CR props more than make up for it. The A400 has singles only because Airbus didn't want to admit the AN-70 had a better setup in the first place.

Power is where the Griffon is lacking vs. a Mouse Merlin, due to the single stage blower. MAII did the same thing as the Bear here and ran nitrous to make up the difference. There are better ways of making power, all have been discussed here.

[Sparrow]

Re: I have the taste of Metal in my mouth!!!

You need a Griffon from a Firefly that has the single porp shaft gear reduction, that's not a 57/58, I think it's a 64. Precious Metal has a 2 stage Griffon which is a Griffon 74 blower on a 68 (?) power section. All that stuff is remains of the Bud days. Finding 2 stage Griffon stuff, even when Zueschel did it for the Red Baron was almost impossible, probably is impossible now. As far as it goes, and NOT because it's BLue Foam, I disagree on the counter-rotating props. The Russians for one thing used it on the Bear which was a very fast aircraft for what it was. They were also driven by turbine engines. In my estimation, the frontal area created by those 6 big blades is to much drag--even though they are shortened quite a lot.

Sparrow

[Eric]

Re: I have the taste of Metal in my mouth!!!

This is some interesting stuff. Hey Wayne, gotta start handing out honorary diplomas in advanced aviaton posting.

[MRussell]

Re: I have the taste of Metal in my mouth!!!

There are big advantages, and the implementation on the RB, MAII, and PM missed things that would buy 50 to 100 mph. Don't fault the technology for lack of development.

?????????

(!!!!!!)

[Wild Bill Kelso]

Re: I have the taste of Metal in my mouth!!!

?????????

(!!!!!!)

When they cut the prop the airfoil section at the tip is going to fast. In a nutshell the prop is not getting out of it's own way. In looking at it this past week you can REALLY see it. Front prop tip is almost 1/4 thick at the tip.

[jarrodeu]

Re: I have the taste of Metal in my mouth!!!

When they cut the prop the airfoil section at the tip is going to fast. In a nutshell the prop is not getting out of it's own way. In looking at it this past week you can REALLY see it. Front prop tip is almost 1/4 thick at the tip.

Is there a "cheap" way to thin it out?

Jarrod

[Victor Archer]

Re: I have the taste of Metal in my mouth!!!

Ahh... I know who you are and KNOW you know of what you speak....

Jogging my memory here.. wasn't the Fury type originally going to run with a Griffon or some other Rolls vairant but they went with the Bristol instead..

The second prototype Fury (LA610) flew on November 27, 1944, powered by a Rolls-Royce Griffon 85 driving a pair of three-bladed contra-rotating propellers. However, this engine was quickly replaced by a 2400 hp Bristol Centaurus XV eighteen-cylinder radial air-cooled engine and later by the 3055 hp Napier Sabre VII twenty-four-cylinder liquid-cooled horizontal-H engine.

I have some photos of the Sabre powered prototype from my Fathers collection. I'll see if I can post one tonight.

[Wild Bill Kelso]

Re: I have the taste of Metal in my mouth!!!

Is there a "cheap" way to thin it out?

Jarrod

Yes there is!!!! The term cheap is relative on the other hand. Here is how I(we) look at it. If you take a 100hp VW and run it into a wall then take a 400hp Corvette and run it into the same wall what happens? You hit the same wall with the same result. The wall stops them both.

[440_Magnum]

Re: I have the taste of Metal in my mouth!!!

atically.

I'd keep the counter-rotating. There are big advantages, and the implementation on the RB, MAII, and PM missed things that would buy 50 to 100 mph. Don't fault the technology for lack of development. If anyone thinks CR isn't a great idea, look at the TSFC of the Russians. Their engines are far less efficient than the western equivalent, yet the CR props more than make up for it.

Correct me if I'm wrong, but aren't the airfoils on the existing Griffon contra-props just about stone-age in comparison even to the vintage Hamilton-Standard props, let alone what the Russians were running in their later contra-prop transports?

I don't have any doubts that contra-props per se can be efficient and great. But I have doubts about what can be done with a contra-prop that bolts to a Griffon (well, with the caveat that you can't burn the whole aircraft budget on the prop.... )

[W J Pearce]

Re: I have the taste of Metal in my mouth!!!

I have some photos of the Sabre powered prototype from my Fathers collection. I'll see if I can post one tonight.

PLEASE DO! That is the best looking Fury in my opinion. It is just beautiful. It was also the fastest at 483 mph I think.

[Blue Foam]

Re: I have the taste of Metal in my mouth!!!

You need a Griffon from a Firefly that has the single porp shaft gear reduction, that's not a 57/58, I think it's a 64. Precious Metal has a 2 stage Griffon which is a Griffon 74 blower on a 68 (?) power section. All that stuff is remains of the Bud days. Finding 2 stage Griffon stuff, even when Zueschel did it for the Red Baron was almost impossible, probably is impossible now. As far as it goes, and NOT because it's BLue Foam, I disagree on the counter-rotating props. The Russians for one thing used it on the Bear which was a very fast aircraft for what it was. They were also driven by turbine engines. In my estimation, the frontal area created by those 6 big blades is to much drag--even though they are shortened quite a lot.

Sparrow

Good stuff. Mike's right, I checked with my source inside hydro racing (a 4-time limited champ) who says that one of the Giffon Bud's big advantages was the near lock they had on some critical parts for 2 stage Giffons.

About the CR, I agree that the history at Reno has not measured up to the theory... yet. Whether it ever will is an open question and Mike has good basis for his doubts.

The drag issue is more of a problem during engine out, and I would say this is one area where ALL unlimiteds could use some help. In the event of an oil system failure, every one of those unlimited props will go flat and convert a high speed glider into a rock with wings. It is far beyond the time to mandate either couterweighted props (which feather on loss of oil pressure) or emergency accumulator systems like the one MAII had. In the latter case, a separate reservoir was attached to a cockpit-controlled valve and was capable of feathering the prop in the event of total oil loss.