It had a liquid aftercooler.
Pinnacle of Piston fighter: XP-72 vs Spiteful Mk XVI? (1 Viewer)
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Reluctant Poster
Tech Sergeant
- 1,776
- Dec 6, 2006
I'm not seeing it in the photos
Peter Gunn
Master Sergeant
OK, trying to keep up here but struggling.
So which is the top option between the V-1710-E27 and the V-1710-H?
And photos would help please...
So which is the top option between the V-1710-E27 and the V-1710-H?
And photos would help please...
Do you need a hammer or a screwdriver?OK, trying to keep up here but struggling.
So which is the top option between the V-1710-E27 and the V-1710-H?
And photos would help please...
A power recovery turbine setup, like the E27, is best for raw power at medium and low altitudes as there is no need to throttle the turbine. A pure turbo-supercharged engine, like the V1710-H, is a mechanicaly simpler and lighter system that offers better fuel efficiency at a slight cost in maximum power
Seversky XP-41 has no place in a turbocharged list. The engine is Pratt & Whitney R-1830-19, a two-stage gear-driven supercharger with an intercooler between the stages, a close relative to the engine used on the F4F-3/4 and FM-1 Wildcats.
The XP-41 is quite well documented in the NACA series reports (e.g. NACA WR E-105)
Shortround6
Lieutenant General
Unfortunately there is a lot of confusion about the XP-41. I believe there were two different Seversky fighters built for the 1939 fighter trials, not sure if they both showed up in time? One had the two stage mechanical supercharger, as you describe. The other had a turbo (the AP-4) and was a company owned demonstrator. The problems seem to be which airplane was identified as what later on. While rather similar (both had the inward retracting landing gear) the air scoops/inlets in the wing leading edges were different.
A lot of books/articles seem to confuse the two planes and often misidentify photos.
The XP-41 had a carburetor scoop above the cowling and unique flush folding landing gear unlike any other P-35 derivative. It definitely lacked a turbo and may have only been a single-stage setup.
In the same vain, the Curtiss model 75R is often claimed to have a two-stage supercharger but in fact was equipped with a turbo. The typical photos in most sources are mislabeled model 75S pictures. This was the actual two-stage model.
Should be 75J and not 75S. Also I'm wrong on the 75R photos being mislabeled.
In the same vain, the Curtiss model 75R is often claimed to have a two-stage supercharger but in fact was equipped with a turbo. The typical photos in most sources are mislabeled model 75S pictures. This was the actual two-stage model.
Should be 75J and not 75S. Also I'm wrong on the 75R photos being mislabeled.
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Can you add a thing or two about this interesting aircraft and it's S/C?
Reluctant Poster
Tech Sergeant
- 1,776
- Dec 6, 2006
The Republic P-47 Thunderbolt Mafia Family
The Jug spilleth over: the manifold relatives of the P-47 Thunderbolt If asked to name an American fighter of WWII chances are most people would say “why the hell are you asking me that?” but…
hushkit.net
Well, a lot of confusion was created over time but there was only one airframe officially designated XP-41, USAAC serial 36-430, the very last aircraft from the original P-35 production batch (36-354/429).
Republic turbocharged developments went on with the YP-43 / P-43 / P-43A series and the P-44 project.
SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
A wonderful article. I learned a lot from it. Looking forward to reading the comments trashing it. (Joking)The Republic P-47 Thunderbolt Mafia Family
The Jug spilleth over: the manifold relatives of the P-47 Thunderbolt If asked to name an American fighter of WWII chances are most people would say “why the hell are you asking me that?” but…
Next time someone brings up the winder waffle
Do 335, I got the XP-72!
The spellcheck corrected "wunderwaffe" to winder waffle, which I like better.
drgondog
Major
I'm late to this, but the XP-51F had the 1650-9 with ADI dropped in it in January 1945
XP-51F – Final Flight Testing with Packard 1650-9
With Packard 1650-9, 90" Manifold Pressure, 150 Octane fuel, Water Injection.
2280 Brake HP at Full Throttle Height (FTH) of 3500 feet, Low Blower; 1855 Brake HP at FTH 17000 feet, High Blower.
1790 BHP at 21,500 feet.
- Gross Weight – 7,553 pounds at takeoff; 7,340 pounds for speed performance testing.
- Top Speed – 491mph at 21,500 feet with 1790 BHP at 90" MP.
- Rate of Climb – 6530 feet per minute at Sea Level @2200 BHP, 5,730 feet per minute at 20,000 feet@1725 BHP at 90" MP
- Absolute Ceiling – 42,600 feet.
Report "Memo Report TSCEF5ER-1883", dated May 7, 1945.
Notes: This airplane had an alternate load of 4x20mm with 125rnds/gun.
In Interceptor/Basic load out with 105gal fuel and Take-off weight of 6990 pounds, Chilton stated 493mph and 7300 fpm at SL, Ceiling 46,000 - only limited by non-pressurization of cockpit - Jan 21, 1945.
IMHO - this airplane was not bought in 1943 (Oct-43 ATSC requested 25 from Materiel Command but rejected by Echols) for any of three reasons. 1.) First use of 75ST (home grown by NAA as Alcoa had not started production when P-51F was beginning design phase, and AAF -MC still leery of 7.33 Limit Load approach, 2. Range - although with 2x75gal externals and 180gal Internal fuel the P-51F had a straight line Fighter Mission combat radius of 702mi, it was less than the P-51B and had no capability of jamming an 85gal fuse tank, or a 1000 pound external fuel tank, and 3.) Oliver Echols still had a hard on regarding North American and still fighting for the XP-75.
It was still very much in consideration for the Interceptor role - but low on priority for AAF.
The P-51H was the result of 'fixing' 1, 2. Arnold fixed 3 by basically moving Echols out of the R&D responsibility of Wright Field.
I devote a lot of time on these topics in my new book.
BarnOwlLover
Staff Sergeant
Not really the best place for this, but any word on the progress of the new book and a possible ETA for retail?
drgondog
Major
I'm done with the draft, perusing the publishing opportunities including self publishing. PM me your real name.
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- #97
That is true if we compare normal production Spitfire and P-47
For example:
Spitfire Mark 24 use engine that can produce 2,375 hp, the loaded weight is 4,500 kg so power to weight is 0.53 hp/kg, and wing loading is around 200 kg/m2
P-47M use engine that can produce 2,800 hp, the loaded weight is 7,300 kg so power to weight is 0.38 hp/kg, and wing loading is 265 kg/m2
That mean Spitfire Mark 24 has about 40% better Power to weight ratio and 24.5% lower wing loading than P-47M. No wonder it can climb better and turn better
But if we compare Spiteful XVI and XP-72
Spiteful XVI use Griffon 101 that can produce 2,420hp, the loaded weight is 4,513 kg so power to weight is 0.54 hp/kg, wing loading 231 kg/m2
XP-72 use R-4360-13 that can produce 3,450hp, the loaded weight is 6,550 kg so power to weight is 0.53 hp/kg, wing loading 235 kg/m2
=>Spiteful XVI and XP-72 practically have the same top speed, power to weight, and roughly the same wing loading
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drgondog
Major
OTOH, the XP-51F failed to get orders in 1943 because it could not install a fuselage fuel tank.
Flight tests in Jan-Mar 1945. V-1650-9 installed with WI.
Memorandum Report TSCEP5ER-1883, dated May 7, 1945
GW= 7340 with 105gal fuel in Fighter condition.
V@21,500 feet = 491mph with 1790Hp; ROC @17,000 ft =5,500fpm
V@SL=420mph with 2,220 Hp; ROC@SL =6,530fpm: ROC at 40,000 ft =530fpm. Max Ceiling 45,000 ft
GW= 8117 with 180gal. Range with full internal 180gal = 1,112mi with 30gal reserve (~approx 40mi more than P-51B). Combat Radius - clean (no drop tanks) = 368mi with 20 min combat at 25,000 ft. (approx same as P-51B with 269gal internal fuel). Average cruise 360mph for that range. Vmax at 80", 25,000 feet = 485mph.
With 2x75-gal drop tanks the yardstick range doubled to 2,000 mi and CR = 790mi with 20 min combat and dropping both tanks with 7gal each remaining.
At full internal GW at takeoff,
Power loading at 90" 2,200 HP = 2200/8117 = 0.27Hp/pound ~ 0.59 Hp/Kg
Wing Loading at 8,117pounds =34psf
Wing Loading with 105gal at 7340 =31.2psf
General Oliver Echols turned down Air Services Command request for 25 production P-51F in October 1943.
6530 fpm of climb is enormous. Beats the best figure for the Bearcat of 6300 fpm.
How long did it take for the P-51F to get to 3000 m?
A (modified?) Bearcat needed 91 second iIrc.
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- #100
Correct me if I'm mistaken but weren't XP-51F were only fitted with V-1650-7 rather than V-1650-9?