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Thanks for the clarification. I have read about the Hydran feed and seen photos of it, but it is rarely mentioned.I may have had a senior moment.
In any case Pages 41 and 43 of Niall Cordaroy's book " Whirlwind" has an account of the Hydran or "M-Type" feed. The feed was a box of vertical cells holding un belted rounds with a worm drive underneath with a pneumatic stepper motor, which fed the rounds. Prototype feeds were made of 121 rounds for the Whirlwind and inner guns of the TYphoon, 114 rounds for the outer guns of the TYphoon and a 300 round unit for the Beaufighter.
The Much published photo of the single gun Whirlwind may be aircraft L6844 which had a redesigned nose and a single 20mm gun with the Hydran feed for testing. The feed did not work under conditions of negative G and stoppages were present even in very short bursts. even after modification.
By August 1940 the plane had been fitted with four guns and magazines for further trials, which revealed two more problems, the 2nd of which was that the magazine consumed air pressure so quickly that after a single long burst the pressure dropped below what was needed to function. The Whirlwind carried no air pump so the only source of air pressure was the bottle in the nose. No air firing of all four guns was carried out.
I have put it into may own words but the source is as above. One or more other publications (soft bound one by 4+ publications) may have accounts of the feeds and problems.
It's a good point on reliability.Twelve .303's each loaded with 500 rounds of AP and Incendiary would destroy any Japanese aircraft with a 2-3 second burst, and be 100% reliable while they do it.
It might be faster to swap out the nose rather than waiting to reload four (or more?) magazines.For tomo pauk
View attachment 603924
The idea was that the guns could use either 60-round drums or belt-feed. Unfortunately I do not have any info on the number of rounds-per-gun for the belt-feed.
Also it might be interesting to note that, during the continued development stage, the different weapon fits were intended to be installed in quick change noses modules.ooooohhhhh!
For tomo pauk
View attachment 603924
The idea was that the guns could use either 60-round drums or belt-feed. Unfortunately I do not have any info on the number of rounds-per-gun for the belt-feed.
Also it might be interesting to note that, during the continued development stage, the different weapon fits were intended to be installed in quick change noses modules.ooooohhhhh!
How many .303 hits would be needed to take out a Betty or Sally bomber?A very effective armament if it worked but it didn't, unreliable ammunition, unreliable guns and even if it did work as designed you only get 9 seconds of firing time, just enough ammunition to walk the rounds onto the target before running out. 12 reliable .303's with 20 seconds of firing time shooting proven AP, Tracer and incendiary ammunition is the best bet.
How many .303 hits would be needed to take out a Betty or Sally bomber?
How does the Whirlwind match up against the Oscar, Tojo or Zero at 10-12,000 feet?
With a gross weight of 10,356 lbs, compared to the Ki-43's 5,710 lbs, the Whirlwind will need all the power it can get.It might also climb better. One Peregrine was making almost the power of an early Sakae (and more with altitude decrease if 100 oct fuel is used by Whirly), and Whilry has two engines vs. one with Japanese.
With a gross weight of 10,356 lbs, compared to the Ki-43's 5,710 lbs, the Whirlwind will need all the power it can get.
AIUI unless the engine is replaced with a higher compression version, the extra octane makes no difference. There are no new Peregrines to be made into high compression engines, so what does 100 or even higher Octane do to help?
In the absence of greater compression. Why?100 octane gives another 100-150 HP
In the absence of greater compression. Why?
But good, our Whirlwinds need all the power they can get.
In the absence of greater compression. Why?
But good, our Whirlwinds need all the power they can get.
Exactly. As I understand it, higher-octane fuel has little effect by itself, its value is that it permits higher boost pressures to be used.More boost.
Thanks, I've been wondering how the octane alone made a difference. My turbocharged car requires 91 octane, and AIUI if I put in 95 or even 100 octane fuel it makes no difference in power with the stock setup, beyond paying more for marketing gimmicks at the gas station. But, if I could adjust the boost level like our Whirlwind pilot can, the higher octane makes more power. Now I understand, I think.Exactly. As I understand it, higher-octane fuel has little effect by itself, its value is that it permits higher boost pressures to be used.
I recall reading that the Merlin engine went through its entire development process using the same valve timing and compression ratio: all of the increases in power (which doubled from 1939 to 1945) were due to the boost pressure being turned up as higher-octane fuel became available.
This is just for making power and has nothing to do with the engine parts being strong enough not to break under the increased loads or the engine cooling system to keep up with increased amount of fuel being burned.