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In the discussion between whether "centre fire (hub)" was better than "wing platform" configuration, I have read in several books and mags, that most German Ace pilots believed that the "wing platform" configurations were more effective for the following reasons:
1). There was more "lead" thrown at the target with a wing platform arrangement.
2). It was more difficult to bring the weapons to bare with the hub arrangement, especially in dog fight situations.
Another thing not mentioned in the discussions so far, is that a relative number of Hurricanes and Spitfires did have 2 40mm wing-mounted cannons in addition to 6 machine guns on the Hurricane and the 4 machine guns on the Spitfires.
Also, I'll get the quote if necessary, many German pilots complained that if they fired too long the 30mm cannon would cause them to lose airspeed. RAF pilots had a similar experience if they fired the 40mm cannons too long.
I've got the info I just need to get it scanned in.
In the discussion between whether "centre fire (hub)" was better than "wing platform" configuration, I have read in several books and mags, that most German Ace pilots believed that the "wing platform" configurations were more effective for the following reasons:
1). There was more "lead" thrown at the target with a wing platform arrangement.
2). It was more difficult to bring the weapons to bare with the hub arrangement, especially in dog fight situations.
Another thing not mentioned in the discussions so far, is that a relative number of Hurricanes and Spitfires did have 2 40mm wing-mounted cannons in addition to 6 machine guns on the Hurricane and the 4 machine guns on the Spitfires.
Also, I'll get the quote if necessary, many German pilots complained that if they fired too long the 30mm cannon would cause them to lose airspeed. RAF pilots had a similar experience if they fired the 40mm cannons too long.
I've got the info I just need to get it scanned in.
I thought the Germans really liked center line weapons if they will work on the plane. I wonder how three 20mm (one in the hub and 2 in the wings) would compare with 4 20mm in the wings against fighters. Run in parallel the center gun fills the void in the center. Go with a 30 in the hub for bombers.
If they had put a single 20mm in each wing of the 109 along with the hub gun as well as the pair of 13mm in the cowl sounds like a strong combination.
How much it was based on the Hispano is subject to question. Some Russian accounts say the V-2 predecessor (the BD-2)was being worked on in 1933-34 which is before the Russians really got going on building the Hispano. The cylinder heads are totally different, 4 valves instead of 2, dohc instead of sohc, intakes inside the V , the engine uses a longer stroke.
A version of the BD-2 was developed for aircraft use and test flown in 1936.
As far as I have found out, he V-2/VD-2 was a direct descendant of the AM-38 diesel aero engine, itself derived from the AM-35. An aero diesel V12 seems quite the advanced concept to go for in 1933-34, what with aluminium tech barely started in the USSR and all. The AM-35/38 seems to have been quite different from the 12Y in many ways. No doubt the Russians learnt a whole lot from HS (and everybody else) but their engineering seems to have been first rate (their production methods may have been a different story). The V-2 is a sturdy and fairly efficient design, even if the fuel injection is rather simple. The same goes for the aero engines. And there is no way they could have adapted the design for a gun mounting through the prop hub. I am not aware of what other engine they used to do that with.
AFAIK the AM-34 (M-34), which was developed in the early 30's, had a distinctly different layout not used in any contemporary engine-everything was shaft driven through bevel gears (it must have been torture to build a prototype!). Not a belt or chain anywhere. And it was a V-12 aero diesel. The AM-35 and AM-38 were further developments. All had superchargers. The VD-2, that was mounted in the BT-7 and BT-8 tanks in about 1937-38 was a reduced size imitation of the AM-38 with no parts really in common but even the bore and stroke had the same proportions. I should have stated that the V-2 design was a direct descendant of that of the AM-38. The V-2, which was used in the T-34, KV and even IS tanks of WWII was a further refinement of the VD-2. And it has been redeveloped, produced in mass quantities and installed in most tanks and many armoured vehicles and even tractors ever since WWII. It is a remarkably sound design. And creating a functional 3D model of it has been a tour de force of engineering study for me. I am not aware of any other significant aero diesel engine than the AM's in the 30's and 40's. The AM-38 and later AM-42 powered the Illyushin Il-2 ground attack aircraft. For more info you could google двигатель М-34 and tanslate the results - wikipedia in Russian has an excellent article on it in АМ-34 — ВикипедияCould you please elaborate about the V2 being a direct descendant from the AM-38? AM-38 being diesel aero engine?
AFAIK the AM-34 (M-34), which was developed in the early 30's, had a distinctly different layout not used in any contemporary engine-everything was shaft driven through bevel gears (it must have been torture to build a prototype!). Not a belt or chain anywhere. And it was a V-12 aero diesel.
The AM-35 and AM-38 were further developments. All had superchargers.
The VD-2, that was mounted in the BT-7 and BT-8 tanks in about 1937-38 was a reduced size imitation of the AM-38 with no parts really in common but even the bore and stroke had the same proportions. I should have stated that the V-2 design was a direct descendant of that of the AM-38. The V-2, which was used in the T-34, KV and even IS tanks of WWII was a further refinement of the VD-2. And it has been redeveloped, produced in mass quantities and installed in most tanks and many armoured vehicles and even tractors ever since WWII. It is a remarkably sound design. And creating a functional 3D model of it has been a tour de force of engineering study for me. I am not aware of any other significant aero diesel engine than the AM's in the 30's and 40's. The AM-38 and later AM-42 powered the Illyushin Il-2 ground attack aircraft. For more info you could google двигатель М-34 and tanslate the results - wikipedia in Russian has an excellent article on it in АМ-34 — Википедия
Tomo, going by memory, I thought the AM-34 was born from a Fiat design and shared nothing in common with the M-17 except both being roughly the same size?M-34 was a descendant of the M-17 engine, that can trace it's lineage to the unsupercharged BMW VI engine, that was a V12 version of engine that 1st run back in ww1. All of whom used gasoline.
The analysis of the V2 by the British School of Tank Technology (May 1944) points out the similarities to the M34 and even includes a photo, although it does point out that there maybe internal differences. It further notes that the M34 was thought to have been originally designed by Fiat.Tomo, going by memory, I thought the AM-34 was born from a Fiat design and shared nothing in common with the M-17 except both being roughly the same size?
Tomo, going by memory, I thought the AM-34 was born from a Fiat design and shared nothing in common with the M-17 except both being roughly the same size?
The analysis of the V2 by the British School of Tank Technology (May 1944) points out the similarities to the M34 and even includes a photo, although it does point out that there maybe internal differences. It further notes that the M34 was thought to have been originally designed by Fiat.
It shared plenty with M-17 - bore, stroke, and, unlike Fiat V12s, articulated connecting rods. Contrary to the M-17, it was an en-bloc engine, with DOHC valvetrain featuring 4 valves per cylinder (indeed, like Fiat's V12s). Why would the Italians design a big engine to the ideological enemy in early 1930s, while not making one for themselves is a mystery to me.
The V2 might as well be a derivative of M-34 engine - it shared features found on the later, including DOHC, 4 valves per cylinder, articulated connecting rods.
FWIW, no Soviet source states the M-34 as foreign-designed engine
Agreed. The Fiat connection seems to have been western speculation. Gunston claimed the M34 was a monoblock M17, but others are not so sure. If it was true that would mean the V2 was originally a BMW design, which is what the Germans claimed.
Agreed. The Fiat connection seems to have been western speculation. Gunston claimed the M34 was a monoblock M17, but others are not so sure. If it was true that would mean the V2 was originally a BMW design, which is what the Germans claimed.
The Germans were selling technology to the Soviets even by the late 30's, so an Italian designed engine made available to the Soviets comes at no surprise.It shared plenty with M-17 - bore, stroke, and, unlike Fiat V12s, articulated connecting rods. Contrary to the M-17, it was an en-bloc engine, with DOHC valvetrain featuring 4 valves per cylinder (indeed, like Fiat's V12s). Why would the Italians design a big engine to the ideological enemy in early 1930s, while not making one for themselves is a mystery to me.