Piston Perfection

[gooberliberation]

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

Just to add again, don't air racers with ex-shackleton engines&props have chopped blades?

[jcf]

P.24
length: 86.25"
width: 43.0"
height: 52.5"

Merlin w/two-stage, two-speed supercharger
length: 88.7"
width: 30.7"
height: 40.0"

Griffon
length: 72.0 to 81.0"(varied by accessories fit/subtype)
width: 30.3"
height: 46.0"

From 'British Aero Engines and Their Aircraft', Alec Lumsden, Airlife 1994 (2003 edition)

Jon

[Glenn Gilbertson]

Sabre comparison from Wikipedia:

Specifications (Sabre V)
General characteristics
Type: 24-cylinder supercharged liquid-cooled H-type four-stroke aircraft piston engine
Bore: 5.0 in (127 mm)
Stroke: 4.75 in (121 mm)
Displacement: 2,238 in³ (36.7 L)
Length: 82.25 in (2089 mm)
Width: 40 in (1016 mm)
Height: 36 in (1168 mm)
Dry weight: 2,360 lb (1,070 kg)
Components
Valvetrain: Sleeve valve
Supercharger: Gear-driven single-stage two-speed centrifugal type supercharger
Fuel system: Hobson injection-type carburetor
Fuel type: 100/130 octane gasoline
Cooling system: Liquid-cooled
Performance
Power output:

2,850 hp (2,065 kW) at 3,800 rpm and 13 psi (0.9 bar) intake boost
3,040 hp (2,200 kW) at 4,000 rpm war emergency power
Specific power: 1.36 hp/in³ (59.9 kW/L)
Compression ratio: 7:1
Power-to-weight ratio: 1.29 hp/lb (2.06 kW/kg)

[jcf]

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.

M-82NV (Ash-82NV)
two-speed geared supercharger, two TK-3 turbo-superchargers, flight tested July-August 1944 in an La-7. No series production.

M-250
24-cylinder radial-block (six blocks of four cylinders each) liquid cooled, geared engine with single-stage, three-speed geared supercharger.
2,200/2,700hp, weight 2,822 lbs. First prototype began bench testing 22 June 1941, production planned from 1943, only ten built, project canceled 1946. Installation had been planned for the Il-2 and a Yakovlev fighter, later intent was for installation in the I-218 heavy fighter/attack aircraft.
Further development of the design led to the larger VD-4K 'Turbo-compound' with three impulse (power recovery) turbines. VD-4K engines were installed in Tu-4 and Tu-85 prototypes.

Ash-2K
'Turbo-compound' 28-cylinder 'Doubled' Ash-82, two-speed geared supercharger, two Tk-2 turbo-superchargers, seven impulse (power recovery) turbines. 3,700/4,700hp, 5,622 lbs weight. Intended as a heavy bomber power plant, developed from September 1949. Not proceeded with as the VD-4K was superior.

'Russian Piston Aero Engines', Vladimir Kotelnikov, Crowood 2005

Jon

[gooberliberation]

Thanks for the info! Its good to know that my idea is somewhat legitimate in that the Soviets did work on turbo-compound radial engines. One thing that I somewhat niglected is that these 3000+hp motors tend to be pretty damn huge.


^^ "Mr. Awesome," a Yak-11(?) heavily modified to take a R-3350 Turbo Compound off a DC-7, with a very noticable fuselage stretch. Later it got a T-33 tail.

The problem:
In order to fit a plausable compound engine, the little Lavochkin will need to be stretched both front and rear, resulting in PITA work for an aircraft that probably won't look that much cooler, plus one that should've started as a more advanced lavochkin to begin with.

The solution so far: I'm pretending that the La-13(which is what I'm calling it for now) belongs in a late WW2 timeframe, entering service no later than 1946. As a result, its engine is a very primitive and imaginary one one with the turbine fairly far removed from the rest of the motor. I'm thinking of putting a shortened engine nacelle off an Me 262 on the belly beneath the wings. Hopefully putting the turbine at the center of gravity wouldn't demand as much a fuselage stretch as a "proper" compound would.

The end result will be ugly and decidedly un-sleek, and hopefully somewhat brutish in appearance. :ar:

[Hobbes]

The turbines used in turbocompounds are fairly small; the ones on the Wright (R-3350?) are comparable in size to a single cylinder.

If you just add a set of turbines to the existing engine (which is all you'd need to improve high-altitude performance and range), you don't need a huge fuselage stretch.

[jcf]

Howzabout a Nomad style installation:


The Turbo-Compound V1710 used a very large, separately mounted combination supercharger drive/recovery turbine:


Hobbes is right about the recovery turbines on the R3350, however, they were small because they were state of the art, also they were a post-war development. The best Soviet turbo was the TK19, a copy of the B-29 unit. The power recovery turbines used on the VD4K were much larger than those of the R3350.

Bell tested a podded turbo-supercharger installation on a P-39 in 1941:


If you go for a podded installation, personally speaking, I wouldn't start with a 262 nacelle as it would be awfully large. A modified droptank could work.

Cheers, Jon

[ysi_maniac]

^^^^
This post is really inspiring. Thanks. It is a pity I have not seen any Nomad nacelle.

[jcf]

^^^^
This post is really inspiring. Thanks. It is a pity I have not seen any Nomad nacelle.

The Napier was only ever flown in the nose of an Avro Lincoln.
You could pretty much make up whatever you want as a 'production' installation.
I don't think you'll have much of problem coming up with something.      

Jon

[ysi_maniac]

See this too: http://users.bigpond.net.au/Shackleton/nomad.html

[Hobbes]

Jon, I noticed you added and then removed a photo link. Is there any way you can make that photo available? I've been looking for photos of those trial installations, but haven't been able to find any.

(guess what my Piston Perfection build is going to use)

[jcf]

Hi Hobbes,
there seems to be a 'don't link' issue, I'll scan and post some other images.

Cheers, Jon

[jcf]

Napier Nomad Lincoln installation:


From Lumsden 'British Aero Engines'.

Jon

[kitnut617]

from the same website as the link Carlos posted, the Shackleton MR.4.

http://users.bigpond.net.au/Shackleton/mark4.html

You can see the wider chord between the inner and outer engines which would have housed the radiators for the Nomad in the leading edge.

[gooberliberation]

Bell tested a podded turbo-supercharger installation on a P-39 in 1941:

Cheers, Jon

Sweet! That's exactly the sort of work I was going for! I didn't think anyone tried it for real. Thanks!