Build an improved Gloster F5/34

[Shortround6]

I'd argue a Twin Wasp would be better.

Because the P-36 with a Twin Wasp was ever so much better than the early P-40 with an Allison?

 

[Elvis]

Indeed. Some bright Aussie paintwork will be needed, like the dazzle scheme used on this Buffalo

View attachment 814048

...Or in modern day at Qantas.

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Or go RAAF anniversary blue (skip the red strips) and swap out the roundels for 'roos.

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It's Oz. Leave the roo's there and call them Roondells

 

[Admiral Beez]

Because the P-36 with a Twin Wasp was ever so much better than the early P-40 with an Allison?

The Twin Wasp would be better because we've already got two Merlin fighters. The only reason for putting the F5/34 into service is that it provides a benefit that does not compete with existing, and better aircraft. That's why I've recommended it to CAC and P&W to get it away from the British Air Ministry's priorities for Merlins and Bristol engines.

 

[Shortround6]

The Twin Wasp would be better because we've already got two Merlin fighters. The only reason for putting the F5/34 into service is that it provides a benefit that does not compete with existing, and better aircraft. That's why I've recommended it to CAC and P&W to get it away from the British Air Ministry's priorities for Merlins and Bristol engines.

When????
You keep recommending a totally fictitious version of the Twin Wasp engine.
You don't have the choice of the 1940-41 versions of the Twin Wasp in 1938.
You NEVER have the choice of 1250lb 1200hp Twin Wasp at anytime in it's history. Wiki is wrong.
The Mercury engine is 1938/early 1939 is not a bad fighter engine. What is has is no growth.
840hp at at 14,000ft is not bad in 1938. Now can you wait for a 'better' engine?
And what is the 'better' engine going to cost in weight?

 

[tomo pauk]

You NEVER have the choice of 1250lb 1200hp Twin Wasp at anytime in it's history. Wiki is wrong.

I was appalled with the last sentence quoted there. Appalled, I say.



Whoops, I've proved you right.

 

[Elvis]

If we're giving the Gloster to CAC the Australians will never want a Bristol engine. And with the 1940-start of P&W Twin Wasp production in Australia, the Wright R-1820 Cyclone is out. I'd like to see a performance comparison between Twin Wasp and Bristol-powered Beauforts.

I think this is the best chance of getting the Gloster F5 into service. We've removed it from the British Air Ministry's oversight, taken over the rights, drawings and any tooling from Gloster's new owners at Hawker Aircraft and thus removed any internal company competition with the Hurricane, and replaced its imported Bristol engine with a domestically produced engine of superior power and reliability.

The challenge is how do we install a longer and heavier Twin Wasp into this airframe, shown below with a Bristol Mercury.

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Perhaps we can move the wing spar and cockpit backwards. Or stick a lump of weight in that fat tail. I like the incline from the windscreen to the nose for visibility, which should be keepable with the P&W diameter. It would be handy to see a cutaway of the Gloster, as perhaps there's empty space behind the engine like on the Skua.

Here's a P&W Twin Wasp. Fourteen cylinders. 30L, 59 in length, 48 in diameter, 1,250 lb (dry), 1,200 hp. And here's what we're trying to replace. The Bristol Perseus. Nine cylinders. 25L, 49 in length, 55 in diameter, 1,025 lb (dry), 905 hp. Doesn't that American engine look space-age by comparsion?

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Are we giving it to Australia? I had no prior knowledge of this. When I mentioned the Pegasus engine, I assumed aircraft that was designed and built in the UK, would be flown by said UK forces.
Seeing how the Pegasus was similar to the Cyclone in displacement, configuration and power, it would make more sense to use an engine already available in the UK, as opposed to importing one in from the US.
...and what family of Bristol engines were the Aussies against? The poppet valve engines or the sleeve valve engines?
Bristol made both.
I could see if it was the sleeve valve engines. That was a troublesome valve train. Why it's pretty much extinct anymore, while almost every reciprocating engine on the planet now is a poppet valve engine.
Both the Mercury and Pegasus were Poppet valve engines.
...however...
IF we are giving the whole design to CAC, then yes, it makes sense to use the R-1830, since its already being built there.
So how do we make a plane work with a 1438 lb. engine (specifically R-1830-S3C4G) replacing one that was 1065 lbs.(Mercury IX)?
You could start by pushing the firewall back. Possibly behind the leading edge of the wing (if that's possible).
If you can push the firewall back a foot (will probably preclude moving the cockpit back a bit, too), that will allow you to install the longer engine, while the overall length of the airplane remains the same.
This gives the heavier engine less of a "lever" for which to move the CG of the aircraft.
Pushing the cockpit back will help counterbalance that extra 373 lbs., too.

 

[ThomasP]

Simply adding armour behind the pilot - similar in layout and weight (125 lbs?) to that in the Hurricane and Spitfire - will make up for 80 lbs(?) of the increased weight of a heavier engine installation. As already mentioned up-thread, the addition of ballast in the tail would have a significant effect also, just at a rough look it seems like it would be at about a 4:1 ratio - so that is another 200 lbs for 50 lbs?. Move the avionics & O2 installations farther back if practical.

Maybe?

 

[Admiral Beez]

Are we giving it to Australia?

I am, FWIW. Anyway, start below.

Build an improved Gloster F5/34

If we're giving the Gloster to CAC the Australians will never want a Bristol engine. And with the 1940-start of P&W Twin Wasp production in Australia, the Wright R-1820 Cyclone is out. I'd like to see a performance comparison between Twin Wasp and Bristol-powered Beauforts. I think this is...

ww2aircraft.net

How about armament? The CAC Boomerang had 2 × 20 mm Hispano (locally made) cannons and 4 × 0.303 in (7.7 mm) Browning machine guns. The F5/34 was intended for 8 x 0.303 in., but perhaps the Australians will up the armament.

 

[SaparotRob]

Because the P-36 with a Twin Wasp was ever so much better than the early P-40 with an Allison?

I'm gonna say "yes".

 

[Admiral Beez]

I'm gonna say "yes".

Me too, if the Hawk can wait for the better Twin Wasp.

HAWK 75:-- PROMISE UNFULFILLED?

"The most advanced production version of the Twin Wasp installed was the R-1830-17 engine, which developed 1,200. The -17 engine represented only the very formative stages of R-1830 development. The Hawk 75 never benefited from the later R-1830 versions, including the single-stage, two-speed supercharged R-1830-90, let alone the two-stage, two-speed R-1830-76, which gave the Grumman F4F Wildcat a new lease on life. The presence of this engine allowed the Wildcat to take on the A6M Zero at higher altitudes.
The empty weight of the Army's standard P-36C was 4,620 lbs. empty, 5,734 lbs. loaded. Weight for the folding-wing F4F-4 version were 5,895 lbs. empty and 8,762 lbs. loaded, although the earlier F4F-3 was somewhat lighter. In a Navy proposal Curtiss estimated a top speed of 351 MPH for a navalized Hawk equipped with the -76 engine."

Under CAC, the Gloster F5/34 will continue development with the contemporary Twin Wasp, until the Grumman Wildcat's two-stage, two-speed R-1830-76 is available.

 

[Shortround6]

Me too. If the Hawk (and the Gloster F5/34) gets the right Twin Wasp once it's available. Until then, the Gloster F5/34 will continue development with the contemporary Twin Wasp.

HAWK 75:-- PROMISE UNFULFILLED?

"The most advanced production version of the Twin Wasp installed was the R-1830-17 engine, which developed 1,200. The -17 engine represented only the very formative stages of R-1830 development. The Hawk 75 never benefited from the later R-1830 versions, including the single-stage, two-speed supercharged R-1830-90, let alone the two-stage, two-speed R-1830-76, which gave the Grumman F4F Wildcat a new lease on life. The presence of this engine allowed the Wildcat to take on the A6M Zero at higher altitudes.
The empty weight of the Army's standard P-36C was 4,620 lbs. empty, 5,734 lbs. loaded. Weight for the folding-wing F4F-4 version were 5,895 lbs. empty and 8,762 lbs. loaded, although the earlier F4F-3 was somewhat lighter. In a Navy proposal Curtiss estimated a top speed of 351 MPH for a navalized Hawk equipped with the -76 engine."

My objection to this P&W R-1830 in the F5/34 train of development is it requires a time machine. At what point in time do the people in charge of the airframe project KNOW when the improvements to the R-1830 are going to happen?
This is one of the classic "what if" problems.
If company (or government) had known in 1938 that engine X with YYYY hp would be available in 1941-42 then they should have adopted the plane in question in 1938 and used an earlier, low powered version until the newer, better version was available.
The R-1830-76 that gave the F4F a 'new lease on life' was actually a developed version of the R-1830-19 which needed a lot of work. So did the -76 engine. The two stage supercharger AND THE INTERCOOLERS were being installed in 1939. Weight for the -19 is not available but the -76 was about 1550lbs, not including the inter coolers. Please note that P&W did not develop/introduce the Two speed supercharger until AFTER they were producing the 2 stage engine. There was no two speed engine until after they had the 2 stage engine in limited production for the F4F in the spring/summer of 1940. It had been announced earlier and they may have taken orders for it but it was not delivered until late 1940.
Starting to build a factory and tooling for plane to use the R-1830 in early 1939 on the hopes that P&W would develop a two speed engine seems like a big gamble.
The R-1830 two speed had a few problems as a fighter engine. The 1200hp started to disappear over 5000ft. Even with a two speed supercharger it was down to 1050hp at 13100ft.
Early radial engines had a lot of drag and little or no exhaust thrust. Both were fixed (somewhat) but to use 1942 fixes to justify a 1939-40 adoption twist things.

Curtiss estimated a lot of things. Curtiss was having problems with Curtiss 75s (P-36s) landing on rough ground let alone smacking down on carrier decks.