CobberKane
Banned
- 706
- Apr 4, 2012
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As good as a Hurricane I is doubtful. The Hurricanes had the 'option' of using 12lbs of boost at lower levels. the Radial engine fighter would not. Getting useful exhaust thrust from the radial is a lot harder than from the V-12.
The Re. 2000 used a better landing gear set up than the Gloster ( at least it turned the wheels to lay flat in the wing like a P-40 rather than having having them hang out the bottom)
and the Re. 2000s ( at least the early ones) didn't have self sealing fuel tanks.
A minor question/problem with the Gloster is that it's payload (difference between tare weight and loaded) is around 200-250lbs less than the Merlin powered fighter prototypes. What wasn't it carrying? Pilot (equiped) 200lbs, eight guns and ammo radio and equipment are all going to be about the same. 200lbs (27 imp gal) less fuel?? Maybe with the Mercury engine it gave the required performance but trying to feed the R-1830?
The Gloster F.5/34 was supposedly good for 306 mph on 840 HP, the Twin wasp should give another 200 HP and was of smaller frontal area, so both streamlining and power/thrust are up, even without using the exhaust thrust. The additional 15 mph seem okay, and it's in the ballpark with Re.2000 and Hurri I.
The increased boost was fine feature for the BoB fighters, unfortunately no use of it was once fighter was above 16000 ft.
All fine, IIRC no fighters used self seasling tanks prior BoB?
Another proposal - bolt the Dagger at the Gloster? Mount the ejector exhausts, too.
While the extra boost can't be used over 16,000ft many fights that started at over 16,000ft ended below 16,000ft. Either for catching the enemy or escaping the radial engine fighter doesn't quite have the option.
It is certainly possible to build radial engine fighters that can 'tangle' with the 109, the trick is to build one that can 'tangle' and win or least have an acceptable loss rate.
Few, if any did, but it is the addition of the tanks and armor that held the Performance of the BoB fighters to near the prototype levels despite increases in power of engines (extra boost, better exhausts) and better props. Any estimates of performance of late 1930s prototype fighters with new engines also have to take into account the increase in equipment (protection/electronics) that the BoB fighters used.
Dagger peaked at about 8,000ft. Offered little more power than a Peregrine at 15,000ft. You just need a new supercharger to go with solving the cooling problems it had
The Mercury offered a surprising 840hp at 14,000ft.
The R-1830 intended for the British Beauforts, a single speed one, ( Australian ones got a different model) gave 1050 hp for take-off and 1000hp at 11,500ft. First two speed US Army R-1830 appears to be the -33 version used in the P-66 and early non-turbo charged B-24s. While prototype planes flew at teh end of 1939 with them production planes may not have shown up until the beginning of 1941.
True on the weight but things like armor windscreens were fitted both inside and outside the existing canopy depending on plane. British also fitted IFF aerials which added drag, rear view mirrors (stretching here) Changing the type of Merlin change the weight very little (until the the two stage engine) while adding 400lbs (or more) to the Gloster is going to affect things. Larger radiators, oil coolers and/or airflow through the cowl for air cooled engines also detract from the maximum calculated speed change.The increased weight will affect more RoC, rather than speed, since most of the improvements were under the skin. Increase of 20% of engine power was (R-1830 vs. Mercury), more than Merlin 45 vs. XII or DB-601N vs. DB-601A
The cooling problems were not reported for the MB-2 IIRC. The Dagger was of far smaller frontal area (kinda hoped you'd state this) and it was far more conductive to a good use of exhaust thrust, as all the inlines anyway.
So the early R-1830s would have maybe 115% of the Mercury's power at 14000 ft? It would've also offered lower frontal area.
True on the weight but things like armor windscreens were fitted both inside and outside the existing canopy depending on plane. British also fitted IFF aerials which added drag, rear view mirrors (stretching here) Changing the type of Merlin change the weight very little (until the the two stage engine) while adding 400lbs (or more) to the Gloster is going to affect things. Larger radiators, oil coolers and/or airflow through the cowl for air cooled engines also detract from the maximum calculated speed change.
From a test on the Hawker Hurricane "Increasing the weight from 6,316 lb. to 6,750 lb. had the effect of reducing the maximum level speed by 6 m.p.h. from 316 to 310 m.p.h. though it should be noted that the engine was changed between the two sets of results."
Adding another 620lbs but changing to a Merlin XX engine (12 gun MK II) gets the speed up to 326mph at the same 20,000ft. Rates of climb at 20,000ft for the light Hurricane I are 1675fpm, heavy it is 1465fpm and the Mk II (12 gun) is 1740fpm.
NOT having cooling problems with a single prototype and having epidemic cooling problems with the same engine in a twin engine bomber in attempted service use give us a conflict. Perhaps the Hereford installation was faulty but there is a difference in running one test airplane on the ground and trying to warm up and take-off multiple aircraft. English weather is one thing, trying to use the same engine/cowl in the tropics might be quite another. One tale is that Herford squadrons wouldn't even start the engines until the planes were facing into the wind. According to some sources some of the Herfords were re-engined with Pegasus engines and turned back into Hampdens.
Yes the Dagger may offer better streamlining and better use of exhaust thrust but it is going to need all the help it can get at higher altitudes and the climb is going to be a real trade-off. Lower drag means more surplus HP but the extra 350-400lbs of engine weight is going to hurt climb. Exhaust thrust is not power, the actual power varies with the speed even if the thrust remains the same. Exhaust thrust is of much less use while climbing than if flat out level speed. A Spitfire will get more 'power' from the same exhaust thrust than a Hurricane because of the better match between the exhaust jet speed and the speed of the aircraft ( OK, not a lot better but measurable)dropping the speed from 300+ mph to under 200mph kills some of the 'power'.
Frontal area was 14.5 sq ft for the Mercury and 12.6 sq ft for the Twin Wasp. The British cowl might have left a little something to be desired too.