Piston Perfection

[kitnut617]

Like, say, replacing the Hornet's Merlins with Griffons and contra-props?

I was thinking 24 cylinder H engines and swept wings.  More later I've my Nottingham to finish.

[kitnut617]

Hmm, I've considered an XP-72 with the P-47N wing for a tad better performance, possibly mated with a five-bladed prop for a more robust and reliable gearbox.

Yes !!!

[gooberliberation]

Not really.  Many piston aircraft developed at the end of the war - Ta 152, Bearcat, Spiteful, Hornet and Fury - were already at the zenith, the ultimate piton engined aircraft and as perfect as they could be. 

The Hornet certainly is and anyone considering anything other than a change of markings is committing heresy.

Like, say, replacing the Hornet's Merlins with Griffons and contra-props?

Weren't the Merlins on the hornet specially designed to have minimum frontal area or something?

I imagine getting bigger engines would require a bit of a stretch in the rear fuselage to make up for it.

[Tojo633]

Guys

Hope this link clarifies a few of the points regarding the hornet/sea hornet and their engines, aerodynamics etc. I think if you read this the aircraft was not designed around the engines as such but the different types/models of engine used were to reduce the torque produced by twin engines rotating in the same direction. Contra props are another way of reducing this on an airframe but would be pointless on the hornet with the engines they used. The slimline engines were specific to the type to improve the aerodynamics and the aircrafts performance with a reduced cross sectional area and streamlined engine cowling/structure.

http://en.wikipedia.org/wiki/De_Havilland_Hornet

Cheers

Sandy

[jcf]

From page 433 of 'De Havilland Aircraft Since 1909' by A.J. Jackson, Putnam 2nd Edition 1978,:
" The exceptional operational success of the Mosquito led, in 1942, to the idea of a scaled down single seat version to be known as the Hornet and capable of meeting single engined Japanese fighters in combat among the islands of the South Pacific. Very long range had therefore to be added to normal medium altitude flight characteristics and perfected streamlining would contribute largely to its success. To this end Rolls-Royce Ltd. closely collaborated with de Havillands and developed special Merlin power plants of minimal frontal area. These permitted an exceptionally sleek installation which was a feature of the mock up shown to Ministry of Aircraft Production officials at Hatfield in January 1943."

The different designations of the Merlin 130/131 and Merlin 133/134 refer to the handing of the propeller drive, otherwise they were of the same 'type/model' and had most of their accessories repositioned to the rear to decrease overall width. Coolant pumps were side-mounted. The engines had the R-R RM.14SM rating.

Rather than trying to fit Griffons to boost power one could use RM.17SM rated 100-series engines... +30lbs boost - 2,340hp, or Merlin 140 based engines. The 140 was designed for the Short Sturgeon, RM.14SM rated and had a counter-rotating propeller drive. Or say what the hell and combine all three: 130 series accessories arrangement, 140 contra-prop drive and the RM.17SM rating. :ar:

Jon  

[gooberliberation]

I suppose a radial-engined trimotor Hornet with spats is out of the question.  

[Glenn Gilbertson]

Some inspiration from the FAA Museum reserve collection, open yesterday:

RR Eagle in the Wyvern:

[Glenn Gilbertson]

For more inspiration, the mighty Fairey P-24 of 1940:

[elmayerle]

Just how close dimensionally to the Sabre is the Fairey P-24?  I'm thinking that a nose from a Sabre-powered aircraft with the props and spinner(s) from a Wyvern would be a good first approximation.  I'd welcome informed comments and opinions.

[GTX]

The Hornet certainly is and anyone considering anything other than a change of markings is committing heresy.

Come to think of it, a Sea Hornet with twin Bristol Centaurus radials is an inviting possibility!!!  Almost a British equivalent to the Tigercat.

Regards,

Greg

[NARSES2]

I'd though of a twin Centaurus Hornet but after a conversation with Lee I agreed his point that it wasn't really on. Therefore my Centaurus will end up on a FAA Tigercat    

[gooberliberation]

I think I know what I'ma do for this GB. A Turbo-compound Lavochkin. Seeing that pretty much every Soviet fighter from WW2 was optimised for low-medium altitudes, I figure they need something to go higher up, to intercept high-altitude Luftwaffe recce planes, or even intercept B-29s in a possible post-war scenario.

Starting with Revell's(Zvezda? Italeri?) La-5FN, fair over the exhausts, add wingtip extensions, a bigger tail, a big air intake, contra-props, and a tube sticking out of the belly.

I suppose an La-7/9/11 would be more ideal to start with, but the -5 is a cheap and readily available kit.

[Glenn Gilbertson]

More detail about the Fairey P-24 Monarch, as posted on http://www.freewebs.com/faireyaviation/aviation.htm:

Fairey had been experimenting with a twin-engine installation driving contra-rotating propellors since 1935 in the face of official disinterest. At one point they had a Battle light bomber (infamous because of the mauling Battles received during the Battle of France) fitted with their P.24 engine driving two props - the Americans were interested for some time in using the P.24 for the new P-47 Thunderbolt but eventually abandoned the idea. Another aircfaft, the Blackburn B20 also considered the Fairey P-24. The "Monarch" engine was of 2,240 horsepower (hoped to be developed to 3,000 hp) and was flying in prototype form in 1939 but was cancelled by the Air Ministry which thought Britain had too many aeroengine companies. Each Monarch engine actually consisted of two 12 cylinder units, each of which drove its own contra-rotating propeller, In May 1940, the grave war situation led to the cancellation of all priority for Hawker Typhoon and Tornado development in order to allow every effort to be put into the production of sorely needed Hurricanes. Design development was allowed to continue, however, and during 1940 three alternative engine installations were proposed for the Tornado- the Fairey Monarch, the Wright Duplex Cyclone , and the Bristol Centaurus, experimental drawings for the Centaurus installation were completed. With the P24 design - there was no "coupling" of its two component halfs - They were two entirely separate engines - one of which drove its propeller through the hollow driveshaft of the other. Other than that there was absolutely no mechanical linkage between the two "halves" at all – So very little to go wrong.
The P24 Monarch was a very advanced engine if the surviving details are true...Compressed Glycol /Water Cooling - As first used in Rolls Royce production engines (Merlin XII) from the end of 1940. RPM of 3,000 (same as wartime Merlins) 2 Stage, 4 Speed supercharger (Rolls Royce only ever managed a 2 speed Supercharger on the Merlin and only managed a 3-speed supercharger on post-war Griffons). With a 2-stage, 4 speed supercharger you would expect the Monarch to have had a very impressive performance at height. There were two designs - The 16 Cylinder H-16 "Prince" of 1.540 hp and the 24 cylinder P-24 "Monarch" of 2,240hp (perhaps more). The H-16 had only a two-speed single stage supercharger. The H-16 could well have boosted a Battle Bomber to close to 300 mph - who knows with a Monarch - 350 mph +  The Fulmar and Barracuda could have had similar boosts in performance – along with "Twin-engine" reliability. Both the H-16 and P-24 used essentially the same cylinders as the earlier P12 Prince - Which had first flown in 1934, and it used poppet-valves, and so would have had none of the problems Bristol + Napier had with sleeve-Valves, so it is by no means unreasonable to think that with a bit of government backing the H-16 and P-24 could have been in production as early as 1938, and certainly by 1940.

As it was CR Fairey said to have spent at least 1 million pounds (at today's prices) out of his own pocket on the project. 'Forsyth went ahead in October 1935 with the totally new P.24, aimed at carrier-based aircraft. Twin-engine reliability was to be gained (for the first time in any engine) by having two halves each comprising a vertically opposed 12-cyclinder unit with a side supercharger, with pressure-glycol cooling. Each crankshaft was geared to its own coaxial propeller of Fairey constant speed type. Each half engine was tested throughout 1938 (the test bed could not handle the 2,200 total horsepower), and on 30th June 1939 the P.24 was flown in a Battle (K9370). With a potential for 3,000hp, the P.24 was considered for the Hawker Tornado and then the P-47 Thunderbolt, the Battle flying some 250hrs at Wright Field in 1942, but wartime pressures forced the termination of what was a very promising engine.' Janes also mentions it flying between June 13th 1939 and December 5th 1941 in the UK with about 86 flying hours being made. Given the fact that it was tested in a Battle suggests it could have gone into a Fulmar, Firefly or a Barrcuda – anybody want to hazard a guess of these aircraft's performance with this engine had it been successfully introduced?

Just think of those P-24 engined Battles and Barracudas, the envy of the world ... must take more water with it .... Monarch engined P-47, anyone?

Interesting thread: www.tgplanes.com/Public/snitz/topic.asp?TOPIC_ID=290&SearchTerms=Monarch

[kitnut617]

Now that is a really interesting engine !

[kitnut617]

just to add, a Wyvern prop is about the same diameter as a Shackleton' prop