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Bringing us back on topic but still related, the Japanese were deficient in both mechanics and supply chain. The Allies would pull parts off a plane to keep another flying, but the Japanese would just leave any disabled plane sitting there until new parts arrived, or just scrap the plane for want of parts and mechanics to install them.
I was trying to simply things. The companies making training/light plane engines are unlikely to design/build high power combat engines. A-S had already fallen through the cracks into the basement. 1st production use of a 2 speed supercharger but the planes using it are banned from overwater flights in peacetime due to reliability. Do you really want them designing your next generation of combat engines without multiple back ups? Same for the other countries.Britain have had 2 major and several minor engine companies, with Napier and A-S in-between?
The cool aid in when people thought that just the design (blue prints) for an engine were enough, and that is before you start modifying anything. Any changes in metallurgy (alloys or heat treatment) can set things back considerably. The Japanese did have a little experience with V-12s but it was dealing with 1920s engines. Kawasaki stuck a supercharger on the BMW V-12 and got it to work but that wasn't that much of a stretch.I have nothing against the DB 601A in 1939-40, even in 1941. However, thinking that in 1942 a 1100-1200 HP V12 will offer an edge over a 1300-1500 HP 14 cyl radial the Japanese companies have experience with, both in design, debugging and production (and with 1500-2000 HP designs in the pipeline) requires a lot of cool aid.
There was no such experience in designing and debugging of V12s in Japan.
The Homare promised an an awful lot and failed to deliver.Did Homare really fell on it's face, or the other factors were to blame, like the octan value of Japanese fuel by 1945, and state of Japasese support industry and maintenance?
How much the Homare promised?The Homare promised an an awful lot and failed to deliver.
I don't know what was promised when but they planned on using it for perhaps the widest selection of aircraft for the both the Army and Navy of any engine the Japanese used in WW II.How much the Homare promised?
I don't know what was promised when but they planned on using it for perhaps the widest selection of aircraft for the both the Army and Navy of any engine the Japanese used in WW II.
Some of the prototype aircraft were flying at the end of 1942 with Homare engines rated at 1800hp for take-off. What they gave at high altitude my be a bit different.
They offered the small diameter, always attractive on the surface but perhaps less so in practice. They were also offering the low weight, within 30-50kg of the Kasei engine.
Let's build an engine under 80% of the displacement of an R-2800. and over 400lbs lighter and use crappier fuel (but we use water injection) but we will get just about the same amount of power because we are so clever?
Or look at it another way, take the Cylinders of a Sakae engine (that was not even making 85hp per cylinder in development models of the Sakae) and use them in an 18 cylinder engine (that won't make over 1550hp) and 'tweak" it to get another 300hp (just to get into the 1800hp area).
Let's say that Japanese take a good and hard look at what Europeans (and especially Germans) were doing with regard to not just aircraft-related technology, but also with regard to mass production of military hardware. Japanese start their 'investigation' once the Tripartite pact is signed, 27th September 1940, and start employing the knowledge gained by some time Spring of 1941 where possible.
To get the ball rolling, I'd propose a ruthless reduction of aircraft types slated for series production, ASAP, along with requirement for protection for crew and fuel tanks for any new A/C design.
edit: time of interest is now from 1937 on; thread is about IJA and IJN military aircraft and whatever is related to that
Rationalising production (fewer types) and training (a greater number of less elite pilots) seems obvious if not much fun.
Can you improve the engines? 18-cylinder radials are hard. Everyone was trying but only the Americans really got a lot of use out of them during WW2. If you're stuck with 14-cylinder the Kasei is pretty good. The Kinsei and Ha109 are not bad but a little small. Possibly some rationalisation here also - too many small engines which sucked up resources but were just not powerful enough by mid war. (Like Bristol - just focus on the damn Hercules and Centaurus!) The Mamoru might have been good if they could make it reliable.
2-stage superchargers? If you want to intercept B-29s you need altitude performance and they were trying but not very successfully (like the Germans). Again, this is hard. Were they missing anything obvious?
Airframes? I don't think they did badly given the engines they were using. The A6M2 in particular is incredible for only 950hp. Could use a bit of tweaking in favour of high over slow speed manoeuvrability, but they were onto that pretty quickly. Probably the A7M was too ambitious a successor, they needed an intermediate with a 1500+hp 14-cyl rather than a 2000+hp 18-cyl (I don't know if the A6M8 would have worked out). The Ki-44 is also good but not a carrier plane and a bit short ranged by Japanese standards. I don't know as much about bombers/recon but what tradeoffs are you willing to make (other than having fewer specialised types in the interests of greater production)?
Armour/armament? Arguably a weak spot but with limited horsepower you face some tough choices. If you want to protect against .50 cal the armour and particularly the self-sealing tanks have to be so heavy you are trashing the performance of early war 1000hp planes, as the Americans found. And if you give up range you give up a lot of the early war victories. Yes to 20mm cannon or HMG a bit earlier on the Oscar.
Both their air forces did about as well as you could ask for at the start of the war. How much could they have improved in the next couple of years before they got completely swamped? I'm really not seeing a lot of plausible opportunity for qualitative improvement except maybe getting a Ki-100 (or less specialised J2M? Shiden or Hayate with Kasei instead of Homare?) type plane with carrier capability a couple years earlier. Not much in the big picture, which is a country punching hopelessly above its weight. As I think I wrote on the German thread...
Well it would have been a useful number if they'd worked reliably, which they didn't, and if your 14-cyl are still working reliably under the same conditions that does indicate a specific problem with the 18-cyl (and if you're going 18-cyl, why as small as the Homare anyway?).Japanese have had a decent production of 18 cyl radials. Homare was a victim of ever-lower production and maintenance standards as the war was closing to the end, as well as fuel octane number not guaranteed to be 91/92 oct (me, I'd go with compression ratio of 6.5:1, if not of 6:1 instead of historical 7:1, in order to be still useful on lower-octane fuel). The Ha-104 was not used on fighters, so there is a missed opportunity. Both of the engines were made in few thousands - not that great when compared with 'Western' production numbers of ~2000 HP engines, but still an useful number.
I don't mean the obvious as in 2-stage superchargers are useful. I meant as in actually getting them to work in mass production versions in time to make a difference in the war, which only the US and UK achieved. Maybe they should have focused more on a mechanically driven 2nd stage and less on turbos which required metals (nickel?) they may not have had?2-stage superchargers were known to work well at high altitudes already by mid-1930s, so yes, they missed the obvious.
Well I nicked that off previous posters.Excellent call on not making the number of specialized types.
Zero needed major engine upgrade at least by mid-1943, so it can sport all the requirements of the modern ww2 fighters: protection, performance and firepower. Kinsei or Ha-41/-109 would've looked just fine on the Zero, so don't wait until 1945 for the nose surgery. In the meantime, have Mitsubishi, Kawanishi and Nakajima work on the next-gen carrier-borne fighter, instead of Raiden, Kyofu and Gekko, respectively; no Saiun, install the cameras on other fast naval A/C.
Why? It's short ranged, not particularly carrier suitable, relatively heavy and would have been late to the party especially once all the cooling issues were sorted. If you ditch the cooling fan what does it offer that's special? Nothing wrong with the Ki-44,-84,-100 airframes and why couldn't the latter two have been made into carrier a/c?Licence-produced Fw 190 (with Japanese engines, guns etc) would've been a boon.
Why? It's [Fw 190] short ranged, not particularly carrier suitable, relatively heavy and would have been late to the party especially once all the cooling issues were sorted. If you ditch the cooling fan what does it offer that's special?
Nothing wrong with the Ki-44,-84,-100 airframes and why couldn't the latter two have been made into carrier a/c?
By the time you give the Zero a major engine upgrade, protection, more/bigger guns, more fuel (in self sealing tanks!) to stop it losing too much range, strengthen the airframe to handle carrier landings with all of the above, and the wings to improve dive speed, how much of the Zero is left? Admittedly the outside is well streamlined so may still be worth keeping even if the innards are unrecognisable.
I don't mean the obvious as in 2-stage superchargers are useful. I meant as in actually getting them to work in mass production versions in time to make a difference in the war, which only the US and UK achieved. Maybe they should have focused more on a mechanically driven 2nd stage and less on turbos which required metals (nickel?) they may not have had?
Well it would have been a useful number if they'd worked reliably, which they didn't, and if your 14-cyl are still working reliably under the same conditions that does indicate a specific problem with the 18-cyl (and if you're going 18-cyl, why as small as the Homare anyway?).
By the time you give the Zero a major engine upgrade, protection, more/bigger guns, more fuel (in self sealing tanks!) to stop it losing too much range, strengthen the airframe to handle carrier landings with all of the above, and the wings to improve dive speed, how much of the Zero is left?
They would have needed strengthening and were too heavy (high wing loading).Nothing wrong with the Ki-44,-84,-100 airframes and why couldn't the latter two have been made into carrier a/c?
Fw190 was a good airplane no doubt, but good enough to go through all the delay of getting the plans out by sub and then producing a foreign design with only blueprints (which went so badly for DB601 engine)? And how much of the low drag is due to the tight cowling/fan combo which you are ditching? Also crazy high wing loading by Japanese standards even compared to Ki-44 (and that will only get worse if you put more fuel in the wings, which will also hurt the roll rate).Fw 190's good points were it's rate of roll, low drag (probably lower than Ki-84 or Ki-100, since the 190 used maller and thinner wing), excellent in dive, high capacity for payload - both internal and external, both for fuel and weapons. It's airframe is/was regarded as very strong.
Yeah I'm just playing with the whole inter service cooperation/standardisation fantasy.Japanese Army had no requirements for their aircraft to be carrier capable.
True but they were stronger airframes to start with, accepted shorter range as a tradeoff, and mostly didn't have to land on carriers (Seafire and 109T excepted). Might still be worthwhile but is it better than a navalised Ki-84 or -100?Take a look into the Bf 109D being turned into Bf 109E, and then into the 109F, G and K. Or Spitfire, from I and II into V and later into IX; or the Spitfire XIV that tracked it's lineage from the Mk VIII, that in return probably took a few tricks from the Mk.III.
If the Ha-104 is so obscure it doesn't even rate an entry in Wikipedia or the list linked above that says something in itself. And 1944-5 really seems a bit late.There is no just one 18 cyl engine in Japanese ervice in 1944-45.
Strengthening doesn't seem impossible (possibly less work than would be needed for an upengined Zero and certainly less than a whole new plane). 35 lb/sq ft also does not seem unmanageable for carrier landings even if a bit more than the Japanese were used to. They look to have reasonable if not stellar visibility forward and good wide landing gear.They would have needed strengthening and were too heavy (high wing loading).
I think we are all in furious agreement on that. Personally I would hazard that as they move to the defensive they could give up some range, but they still need to be lighter than the Americans especially if they don't have 2-stage supercharging, so that means less protection and dive speed. (I'm wondering if the weight penalty of protection against .50 cal is too much even with 1500+hp, at least for the fuel tanks.) So maybe Tomo's push for the A6M8 makes sense after all.The Japanese cannot match the American planes. They have to give up something or more than one thing. They could do better than they did and come closer.
Fw190 was a good airplane no doubt, but good enough to go through all the delay of getting the plans out by sub and then producing a foreign design with only blueprints (which went so badly for DB601 engine)? And how much of the low drag is due to the tight cowling/fan combo which you are ditching? Also crazy high wing loading by Japanese standards even compared to Ki-44 (and that will only get worse if you put more fuel in the wings, which will also hurt the roll rate).
Yeah I'm just playing with the whole inter service cooperation/standardisation fantasy.
True but they were stronger airframes to start with, accepted shorter range as a tradeoff, and mostly didn't have to land on carriers (Seafire and 109T excepted). Might still be worthwhile but is it better than a navalised Ki-84 or -100?
If the Ha-104 is so obscure it doesn't even rate an entry in Wikipedia or the list linked above that says something in itself. And 1944-5 really seems a bit late.