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Unreliable? Yes. Not powerful enough? Definitely not.I think one of their main trouble would have been a reliable and powerful enough engine.
Depends on which Merlin. while ahead of the DB601A looks good at first glance, the Germans were sticking DB601 engines in 109s/110s in late summer and early fall of 1940.The 12Z engine was quite powerful for its time, being a bit behind the Merlin and well ahead of the DB 601A.
This is about as close to vaporware as you can get and actually have pictures. What you actually have is a handful of engines that actually flew in WW II (with a finger or two left over)I've also admittedly not heard much about the 157's 14R beyond its power and capabilities, so I can't speak further about that one's reliability.
Figures from Wiki are from the 1946 edition of Aircraft Engines of the World 1946. and require 100-130 fuel, a two speed supercharger and a direct fuel injection system and a lot of faith.
There are several false claims in here, like " an increase in cylinder capacity," which is very hard to do if you don't change either the bore or the stroke (or add cylinders).
I've also admittedly not heard much about the 157's 14R beyond its power and capabilities, so I can't speak further about that one's reliability.
Unfortunately no, I'm relatively new around here and haven't delved too deep into radial engines. Most of my "knowledge" about the 14R comes from scattered bits and pieces around the M.B.157 so I cannot in good faith say I have any authority to make claims about it.What data you have on the 14R? Anything resembling a primary source hopefully?
The French in 1940-41 (assuming they survive) have a number of problems. While work started on the 12Z in 1938 it was still very much a prototype engine in the Spring of 1940.My take on the newest and bestest French fighters - a HS 12Z with 1400-1500 HP at altitude (~5.8 km?) puts them in very good position for 1941-43. So does the G&R 14R, that was making the power in-between the BMW 801C and fully-rated 801D. French fighters were of small size, and Germany was just across the Rhine basically, so the fighters can do a lot of good work if France is still in the fray.
French have just a minor favor to ask - that Germans don't crush them in 1940, and I'm afraid that is asking a lot.
You can't make 12Z engines using 12Y machinery in the factories. Or at least you can't make many of the parts. Changing from 2 valve SOHC heads to 4 valve DOHC heads requires new castings and a lot of new tooling. New crankshaft and new connecting rods. Maybe you can use the old machinery to work on the blocks?
It is not like we're trying to tool-up the car factories to make aero engines.The G-R 14R is in a similar situation only worse. You need new tooling for one thing.
Country being conquered can have it's downsides.One flying sample of the engine disappears into Germany, next engines show up in late 1944?
four more engines are flown in 1948?
As noted in earlier threads, the Soviet M-105 and the Swiss Saurer YS-2 were improved versions of the basic H-S 12Y engines somewhat comparable to the 12Z. Neither got 100 octane fuel and neither got anywhere near the claimed power out put of 12Z.
Basically you have a poppet valve Hercules that runs 200rpm slower. It is about 190lbs lighter.
The Arsenal VG-40 and Dewoitine D.521 with their intended Rolls-Royce Merlin engines would have addressed such issues.I think one of their main trouble would have been a reliable and powerful enough engine.
Wright and P&W also significantly re-tooled for some of the R-1820, R-1830, R-2600 and R-2800 engines.It is not like we're trying to tool-up the car factories to make aero engines.
Yes, so many months will be needed to change the part of tooling, similar as it was needed for the factories making the switch between DB 601 and 605, or these making a switch from Jumo 210 to 211 (and later the 211 into 213).
Very true, but in 1947-48 when the last 14R engines showed up (my mistake, eight engines and spares?)Country being conquered can have it's downsides.
Saurer is supposed to have 93 octane for the YS-2. Late 40s used 91/98 octane?Soviets did got the 95 oct fuel. Saurer certainly did received hi-oct fuel after 1944?
I don't think that M-105 was comparable to the 12Z, it was barely better than the 12-51. The M-107 was probably the equivalent.
No. The 14 R was the development of the 14 P, which itself was the development of the 14 N. Certainly not a "new" engine.The G-R 14R is in a similar situation only worse. You need new tooling for one thing. One flying sample of the engine disappears into Germany, next engines show up in late 1944?
If the 12Y-51 is the best they have, then I might be able to add another plane to this list of potential main fighters: The D.551.Wright and P&W also significantly re-tooled for some of the R-1820, R-1830, R-2600 and R-2800 engines.
But it takes months. Lots of months. In 1940-41 France is stuck with the 12Y-51 at best and it may have had problems?
But it takes months. Lots of months. In 1940-41 France is stuck with the 12Y-51 at best and it may have had problems?
Very true, but in 1947-48 when the last 14R engines showed up (my mistake, eight engines and spares?)
There were proposals to use Bristol Hercules 730 (licensed by SNECMA, same company) and Jumo 213s being built in France.
By this time the Hercules was into the 230/630/730 series engines which, like many radial engines, pretty much kept the bore and stroke of the earlier engines and very little else.
The M-105 is sort of an in-between engine. It had 3 valves per cylinder while the French, Spanish and Swiss engines had either 2 or 4. M-105 also had two speed supercharger which was a rarity on the non Soviet Hispanos. Yes the soviets had to wait for the V-107 to get 4 valve heads and DOHC.
2600 rpm for the M105, although the German docs say 2700 rpm.RPM limits on these engines was all over the place. 12Y-51 was 2500rpm. The YS-2 was 2600rpm (?) the YS-3 and YS-4 was 2800rpm. The 12Z changed from 2600rpm on early versions to 2800rpm. M-105 started at 2600rpm (?) and raised to 2700rpm and perhaps even 2800rpm?
As opposed to the SE.520Z which was an overhaul of the existing D.520's frame using the 12Z, the D.551 was an almost completely different aircraft using the 12Y-51 (Although the D.554 model was slated to use the 12Z). It had excellent performance even when armed, in Danel and Cuny's books about the D.520 they claim a top speed of ~660 km/h at 4,000 meters.
Do you have any information about this 12B engine? I can't seem to find anything online about it other than that it existed.The 12 Z never ran satisfactorily (see tremendous exhaust smoke traces on BV 10 fuselage...) and was supplanted by the Hispano 12 B - designed by ing. Jacques Blanc, who had drawn before war... the G&R 14 R !
Already M-105P/PF operated at 2700 rpm at higher altitudes - I can post scans (in Russian) if necessary. M-105PF2 was not _much_ heavier - the difference between 105PA/PF/PF2 was rather negligible (600-620 kg, the PA could be converted into the PF during repair). Indeed, only the M-107A was significantly heavier.2600 rpm for the M105, although the German docs say 2700 rpm.
The VK-105PF2 went to 2700 rpm, while also making a much greater boost (it was also a much heavier engine than the M-105).
Indeed, I've chaecked out the weight fgures, seems like the earliest M-105s were at 570 kg.Already M-105P/PF operated at 2700 rpm at higher altitudes - I can post scans (in Russian) if necessary. M-105PF2 was not _much_ heavier - the difference between 105PA/PF/PF2 was rather negligible (600-620 kg, the PA could be converted into the PF during repair). Indeed, only the M-107A was significantly heavier.
Early M-105 - 570-580, PF - 600/620 (according to different sources), PF2 had only minor differences from PF - the weight in principle could not change appreciably..Indeed, I've chaecked out the weight fgures, seems like the earliest M-105s were at 570 kg.
Any original docs are welcomed here.