Shortround6
Lieutenant General
Sorry to intrude on the current discussion, but I felt that I had to post a retort.
Respond, don't respond, its not important right now. I just feel that the below quote needs to be addressed.
The post in question...
My response...
Shortround6,
It seems you either completely misread my post or am intentionally responding in a way to sway the discussion in a way it was not intended. I don't know which, but you've done this before, so I'm becoming a little suspect of your actions.
In your response (quoted above) you go on about Merlin engines, but my only purpose for bringing up the Merlin is to show that the -45 Allison engine had enough ponies to use the version of the H-S prop I mentioned.
...and I understand what Clay was getting at, by mentioning the P-39.
The point here is that the P-51 never exists in the first place (or comes along much later than it actually did) because N.A. went ahead and built those P-40's for the British, instead of what really happened.
THUS, the P-39, with its big 37mm gun, becomes the Ground Attack / Bomber interceptor and the P-40 is then further developed into the Fighter interceptor / Bomber escort.
This is why I'm so keen on a combination of the IA version of the -45 engine and that H-S prop.
Because the idea IS to make the P-40 into a better high altitude fighter and the engine dates closest to a time period when that development work was being done (although I'd like it better a year or two earlier).
Elvis
I am sorry you feel that way. I admit to having a tendency to ramble.
The point as to the Merlins was that quoting take-off power, while useful somtimes for identifing the model of the engine, doesn't always relate to the actual design requirements of the propellor. I had hoped that was clearer.
The -45 engine was rated at 1325HP at sea level, 1150hp at 21,000ft.
The Merlin question (-7) was rated at 1720HP WER at 6,200ft and 1505 HP WER at 19.300ft. roughly 30% more power than the -45 Allison. I can see where it needed an extra blade for more area.
THe P-38K that used the big prop was rated at 1425Hp at 27,000ft (air about 1/3 as dense as sea level) and 1600hp at WER. I can see where fitting the big prop to those engines would increase performance over a propellor designed for 1300-1100hp at sea level/27000ft.
what I don't see is how the bigger propellor increases performance on the lower HP engine.
I thought I had gone over that in the original post. Please show me that I am wrong about this if you feel that the H-S prop would over a significant advantage. Can you come up with any performance figures just from a propellor swap and not trying to compare plane with a Paddle bladed prop that has 10-30% more power at the same time to a lower powered plane without the paddle blades.
I am glad you know what Clay was getting at when he brought in the P-39 because I didn't have a clue.
I have no idea of what the russians thought about the P-39 has to do with the altitude performace of the P-40, either real or fantasy. Unless his proposed modifications to the P-40 make it unusable at the lower altitudes something like a MiG-3? Strange that the German 109s didn't have this problem. or the Spitfires or the P-51. Their performance did change with altitude but they didn't REQUIRE a second fighter to cover that part of the sky for them.
You can make the P-40 a better fighter in the 20,000-25,000 ft area than it was. the question is can you make enough better to actually make a big difference.
Edit> lets take a hypothetical situation. Say at a certain altitude the Bf-109 has a climb rate twice that of the P-40 (normal) and due to the proposed modifications you increase the climb rate at that altitude by 50%. That is a considerable increase in performance and yet you are climbing only 75% as fast as the 109 (or the 109 is still 33% better). Has your improvement really altered the relation ship between the two aircraft or changed the tatics that each would use in combating the other?
This is the real question. Can you improve the P-40 ENOUGH to make a substantial difference in performance, ENOUGH to enable P-40 to change how it fights the 109?
If all you have done is reduce the time it takes for a P-40 to dive on a target and past it and then climb back up to attack altitude from say 10 minutes to 6 minutes have you really changed much of anything? THe improvement looks very good on paper (and it is) but if the target just continues to fly straight and level at even 300mph it will be several miles away by the time the P-40 is back at attack altitude. The only advantage you have gained is the ability to get into attack position (the first and maybe only time) a bit quicker. Say your squadron is flying at XXX height and is radioed that attackers are coming in at height YYY from direction ZZZ and are QQ miles out. THe "improved" planes might have the performance to climb to attack position before the attackers pass them when regular P-40s might not.< end edit.
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