Historical Engine technology

[Kanonier Reichmann]

nayone wish to hazard a guess as to the WW2 aircraft most able to approach the speed of sound in a dive? : )

For piston engined airdraft I'm guessing the Pfeil (a really unique and clever design with a push/pull in-line engine design) and for Jet aircraft I'm guessing the Me262.

Anyone wish to hazard a guess as to the fighter throwing the most lead?

Assuming this question applies to the entire war I would have thought the Me262 would be right up there with its 4 x 30mm cannon.

Regards

KR

[dieseltaylor]

Spitfire - approacing 0.9 Mach in a dive. And aso capable of flying at 65mph. Some trick. The high speed coming down to having the thinnest wing section at 13%.

1] Lead throwing contest was for August 1939 fighters.

Interesting data from the book is three to four 30mm hits would be sufficient to bring down a large bomber, a single hit to kill medium bomber and fighter. As for the German 30mm cannon Mk108 used in the Me 262 [and other German fighters] it was lethal but the velocity was low so that shells took 2.5seconds to travel 1000 yards and dropped 100ft in that distance. Rate of fire 660 rounds per minute - but with 90 rounds per gun it was restricted to how much it could accomplish.

For 20mm it was reckoned 20 hits were required for a US heavy bomber - obviously ignoring the chance of a lucky hit on the cockpit. German camera footage was showing around 2% of aimed fire from an average FW 190 pilot was hitting. So to get the required number the plane neede 1000 rounds - and 23 seconds of firing. Not very likely. Aces were those who aimed better or who picked off previously damaged planes.

2] Any takers on a fighter type aircraft with the longest range?

[womble]

Spitfire - approacing 0.9 Mach in a dive. And aso capable of flying at 65mph. Some trick. The high speed coming down to having the thinnest wing section at 13%.

That'd be the late war variants like the Mk XXIV, no? Battle of Britain models weren't that fast were they?

1] Lead throwing contest was for August 1939 fighters.

'Pends how you're counting: number of rounds, it was probably the .30 calibre armed Spit, rather than the German planes with fewer, heavier-hitting, slower-firing cannon mixed into their armament.

2] Any takers on a fighter type aircraft with the longest range?

Me 110 in the early war european theatre, or Zero in the pacific, maybe, would be my guess. Later, P-51s and Lightnings?

[dieseltaylor]

1] Polikarpov I-16

Some of the best machines guns and cannons. Double the firepower of the Me-109 and nearly three times that of the Spitfire I

2] P-82 Twin Mustang. Actually re-reading it I cannot claim it was a combat aircraft . ..darn. Anyway one of these flew from Honolulu to New York non-stop. Top speed 482mph.

SO this question remains open ,,, I will need to find the answer.

The Mach speed was achieved by a Mk XI during a trial at Farnborough in 1943. Trials also established that by various cleaning up exercises on a Spitfire V a further 28.5 mph could be added to the top speed. This included a whip aerial, different exhausts, new rearview mirroe[!], polishing an stopping wing and three or four other tweaks.

The Mustang laminar flow wing and fuselage was great for improved performance but would degrade quite quickly when dirty or insects built up on the wing front. One has to wonder whther its top performance was the same as its normal in-service performance. The tolerance was very fine , on the wing, .0005 of an inch.

[Michael Emrys]

2] P-82 Twin Mustang. Actually re-reading it I cannot claim it was a combat aircraft .

Not in WW II. But it did score at least one kill in Korea, IIRC.

Michael

[Stalins Organ]

Longest range I'll opt for the Ki-84 Hayate, with 1339 miles - a smidgen more than the P-38 & a couple of hundred more than the P-51 - all without tanks of course

[coe]

anyways, to return to the earliest part of this thread, what was causing allied HP to be more than Axis HP towards throughout the war?

[Stalins Organ]

I'm not sure that the initial premis is justified in the first place - it's just been made as a statement with no evidence.

So perhaps a beter way to get back to the question is to provide a list of the evidence?

However things we do know that might ecxplain it if it is "real" -

1/ better fuel certainly helps

2/ simply more engine development. This is a result of greater industrial capacity and a "deeper" aviation programme - but which I mean looking at more types of a/c (eg 4 engined heavy bombers), from more manufacturers and having started development earlier and/or kept it going rather than cancelled it.

this is also related to the German successes in 1939-40, which saw a plethora of projects cancelled as "not going to be needed" since they were going to win the war anyway, whereas the Brits & US were just starting to get going.

there's a book out there "Luftwaffe Strategy for Defeat" by Williamson Murray that gives a good overview. I have a pdf of it from somewhere but cant' find it on the net anywhere except amazon reviews, etc.

also for a case study of engine development there's a 1945 article/lecture about Merlin developement 1939-1945 on the WW2 Aircraft performance page that might be interesting.

[ArgusEye]

If we are concentrating on aero engines, the situation becomes slightly different.

First: the Germans (and to a lesser extent, the Japanese) were trying to economize on strategic materials, and were trying to use smaller planes with smaller engines.

Second: The Germans decided to switch over to jet tech, and cut back on piston engine development. They still did it, but the main effort became jets. So later on they were not competing so hard.

Third: Fuel, as I wrote in my first post of this thread.

[Stalins Organ]

Here's a site with basic engine data - but not date of introduction.

I note that Germany, the US & UK each only have about 2 or 3 basic engine types that get 2000 hp or thereabouts - but in the USA's case they have a lot of sub-marks of the R2800 especially that seem to inflate the numbers!

UK: Sabre, Centaurus, Griffon (3 completely different styles of engine - H, Radial sleeve-valve, and V!)

USA: R2800, R3350. The R2600 almost makes it at 1900. All are Wright radials.

Germany: BMW 801F (development halted by end of war), DB 603 & 605 (a radial & 2 V's)

[Michael Emrys]

All are Wright radials.

Wrong. The R-2800 is a Pratt & Whitney.

Michael

[Stalins Organ]

Ah..so someone does read.....

[dieseltaylor]

Alfred Price puts it down to the Germans not developing their engines further. As to why not several reasons are supplied above.

It may be that this book could give reasons:

Major Piston Aero Engines of WWII [Hardcover]

Victor Bingham (Author)

actually a little searching reveals an interesting thread here

http://warbirdsforum.com/archive/index.php/t-1431.html

German Airo Engines They Were So Unique

[Stalins Organ]

Looking through wiki articles on the BMW, DB & Jumo engines, it seems that chemistry was a pretty important part of the equation - getting 2000 hp from the BMW radials, Jumo 213 & DB605 required use of C3 (100 octane) fuel, and also water-methanol injection for the DB & BMW.