Admiral Yamamoto's "What Might Have Been"

[John 3rd]

If you did build a plant in Anshun Manchuria what would the impact be for those later models with the much larger/more powerful engines?  What would you do with final, late-war development and deployment of fighters?

[John 3rd]

ORIGINAL: bklooste

Interceptor Path
A6M3  42/2 All Jack sentai become A6M3 ( as historical)

A6M3a 42/6

A6M3b 42/5;
Altitude 37000
Max speed 341
Cruise 240
Endurance 270 ( compare to 450 for a A6m3A)
Climb 2870
Armour 1 , Dur 25.
2  Nose 7.7mm , 2* 20mm ( dropped the extra 12.7 in favour of protection and balance)
Max load 441
Maneuver as A6M3A
34/34/34/28/22
1 * 150L Drop tank for redeployment.
1 * 30kg bomb
A6M3A internal fuel tank was 570 L , we reduce this by 230L to 370L 40%.
We Increase armour by 110kg
Overall weight is reduced by  150kg drop tank , 230kg fuel = 380kg (more if it takes of with bombs) and we spend 110kg
= 270kg or ~10%-15% lighter.
I have conservatively increased speed by 1.5% , climb by 6% and max altitude by 0.5% to reflect this.


A6M4 43/1(Compared to A6M8 with same engine)
Carrier capable
Altitude 38075 (+1000)
Max Speed :358 (+2)
Climb 2970 (+3%)
Cruise 230
Endurance 270 ( -15)
Armour 1 , Dur 27.
2 * 12.7mm , 2* 20mm
Max Load 441 (-600)
Maneuver:  30/30/30/18/11 ( No super charger)


A6M4i 43/8
Maneuver:  30/30/30/23/17
Upgrade 20mm to Type 2 30mm Cannon.

A6M4i upgrades to A6M8 and the A6M8i ( to cover A6M3 path)

A6M8i 43/12
+ 2 Dur. 
Maneuver:  31/31/31/25/19
A6M8i upgrades to the J7

J7 Shinden avilable 5/45 this plane would greatly benefit from work

Factories.
All J2 factories become Zero and upgrade automatically when available A6M3 -> A6M3 -> A6m3i -> A6m4 ->a6m8i .

The  Factories producing some Mitsubishi Ha-32 for the Jack are converted to Nakajima Ha-34 Just move some numbers over.
43/1  Nakajima Ha-33  factory for Dinah ( and A6M4)  is increased by 20.

Note im deliberately creating a shortage of this engine to encourage more M5 for efficiency reasons

Comments:
1. Do you actually need to deploy the 3a since it was the follow-on successor to the CV-Based M2? FatR has the line simply jump to M5 from M2. If so, then the Interceptors go M3, M3b, M3i, M4, M8i.

2. Agree with all J2 Factories becoming Zero. Could we simply dedicate these factories to the Interceptor path to reflect this design branch?

3. The Jack's engines could go to Ha-34 but could we also split one of those over to George's engine to reflect more work there too

4. The M3b design as you list doesn't have an increase in armament, has more protection, reduced range, and better climb. Seems to be a fairly conservative move into the Interceptor Line.

5. Adavance George as described earlier?

6. Shinden at 5/45? Could that come forward or do you leave it where it is and have the player research to try and bring it forward?

[bklooste]

Non Zero models benefit a bit from extra resources.
 
All George models come in 1-3 months earlier , 6 months for N1K5.
 
N1K1 9/43 -> 8/43 (-1)
N1K2 11/44 -> 6/44 (-3) actually N1K1 was produced in 2/44 but in quantities of 1-2 till the 11th.
N1K5  10/45 -> 4/45 (-6)
 
 
A7M1 cancelled
Go for the more reliable A7M2  with the Ha-43 and lets say 44/11.
 
G3M4 Nell  , Nell using the Ha-33 which is a slot in replacement for the G3M3.
Available 43/6 Max speed 285 , Endurance 800 , Armour 1.  Uses high demand engine.
 
No changes to factories for these ( though they are brought forward)  if you want them it will cost.

[bklooste]

ORIGINAL: John 3rd

ORIGINAL: bklooste

John what about the idea of a modified 5th Cirlcle which can only be built as per HR when 3 CVs are lost .

I agree to that thinking, however, how would you Mod that. Should you place all CVs after the 3 Shos on 'do not build' or whatever until you've lost several or do you simply keep them frozen until a given date and then allow for construction?

Cheaper quicker ,Uruyus wouldnt affect the Shos unless the player chose. Prob the BCs and CAs would become CV /CVL and this can be shown as a conversion which can only be done if teh 5th circle mod is avaialble eg it adds 30 days , so the moment you get your BC you can put her back in the docsk for a quick conversion .

[bklooste]

ORIGINAL: John 3rd

If you did build a plant in Anshun Manchuria what would the impact be for those later models with the much larger/more powerful engines?  What would you do with final, late-war development and deployment of fighters?

The plant WAS built ( and there were deals done with Germa companies) its regarded as a bit of an engineering disaster ( PM /chemical engineering studies use it) as they didnt build a pilot plant and it was a disaster the lab knowledge was there but not the practical engineering /experience. A more successfull plant ( say like the ones they built in Germany but much smaller) would have massive impact , though its hard to quanitfy such a what if and would have used a lot of steel resources , note it is even strategically significant since then there would be much less need for the move South since Japans economy required a LOT less oil then germany. Anyway im just using it to produce some 100/130 octane fuel which can be blended so we can get over the Nk series engine issues.

[bklooste]

ORIGINAL: John 3rd
1. Do you actually need to deploy the 3a since it was the follow-on successor to the CV-Based M2? FatR has the line simply jump to M5 from M2. If so, then the Interceptors go M3, M3b, M3i, M4, M8i.

2. Agree with all J2 Factories becoming Zero. Could we simply dedicate these factories to the Interceptor path to reflect this design branch?

3. The Jack's engines could go to Ha-34 but could we also split one of those over to George's engine to reflect more work there too

4. The M3b design as you list doesn't have an increase in armament, has more protection, reduced range, and better climb. Seems to be a fairly conservative move into the Interceptor Line.

5. Adavance George as described earlier?

6. Shinden at 5/45? Could that come forward or do you leave it where it is and have the player research to try and bring it forward?

1. The 3a is as historical and is still a successor to the M2. Players can skip or they jump straight to M5. The choice is there why deny it ? eg short term improvement but you have to convert many factories yourself or standardize and save HI.

2. Note they become Zero interceptros on the A6m3 path . Yes on the factories

3. No due to issues with the George engine. We are bringing the George forward which will bring the factories forward but you wont be able to build the Quanity straight away.

4. Yes the M3b is designed as a war time measure to handle interceptors being shot up by bombers defences focus is more on climb etc. Esp zeros will fair much worse than Jacks. Note it does have the 99-2 20mm cannons.

5. In next post

6. Yes any planes with canards is great historically its a 12/45 plane. It would benefit greatly from any work but its a pretty advanced plane so i took it as +6 months. There is also a jet version ...

[bklooste]

The carrier fighter line (conservative, emphazis on mass production)
A6M2
-> A6M3a (42/6) [Option] no auto upgrades of facilties
->A6M5 (42/10, no changes)
->A6M5b (43/3, no changes)
->A6M8 (was 43/8)  suggest available 43/6 with factories auto upgrading 43/10  , max speed 358. + 1 hex to all ranges.
->A6M9   44/4  auto upgrade refinement of the A6M8  Additional +1 hex to all ranges , +1 manuever at top 2 altitudes ,  max speed around 365, reflecting the overall design polish and improvements to the Kinsei engine, otherwise no changes) .Max load 1400.

Note engine factories dont upgrade eg no Sakei to Kinsei freebies.

[PaxMondo]

ORIGINAL: bklooste

ORIGINAL: John 3rd

If you did build a plant in Anshun Manchuria what would the impact be for those later models with the much larger/more powerful engines?  What would you do with final, late-war development and deployment of fighters?

The plant WAS built ( and there were deals done with Germa companies) its regarded as a bit of an engineering disaster ( PM /chemical engineering studies use it) as they didnt build a pilot plant and it was a disaster the lab knowledge was there but not the practical engineering /experience. A more successfull plant ( say like the ones they built in Germany but much smaller) would have massive impact , though its hard to quanitfy such a what if and would have used a lot of steel resources , note it is even strategically significant since then there would be much less need for the move South since Japans economy required a LOT less oil then germany. Anyway im just using it to produce some 100/130 octane fuel which can be blended so we can get over the Nk series engine issues.

While this accurate, the octane issue was mostly a different issue. As you suggest, IF Japan had been able to build this Fischer-Topsch unit it would have lessened some of their needs after the US embargo. The FT unit takes coal and converts it to a LNG type fuel which can either be burned as is or refined to other fuel products.

Japan's octane problem went back to the other point you made: steel production and quality. There two ways then to make high octane av gas: HCC (HydroCatalyticCracking) and Alkylation. They work oppositely, HCC cracks very heavy oil into lighter and Alky combine very light into heavier. HCC requires very high temp steels, Alky requires special acid resist steels. Both of which JAP struggled to make pre-war, and then during the war refineries are obvious and easy targets. Why they struggled is more difficult to pin-point. My opinion is that it was due to NIH/ego, but I have never read any supportable reasons for this nor really have I run across anyone elses.

If you assume that JAP was able resolve her octane problem (and GER struggled with this as well from '44 on due to allied bombing), then the later engines become far more reliable and come sooner (testing is more efficient).

How big of an assumption is this? Hard to say. From an engineering perspective, all of this was within their capability. The steel compositions required were well known and public domain, and pre-war the hardeners were readily accessible on the market. GER stockpiled these things for years prior to 1939.

[John 3rd]

ORIGINAL: bklooste

ORIGINAL: John 3rd
1. Do you actually need to deploy the 3a since it was the follow-on successor to the CV-Based M2? FatR has the line simply jump to M5 from M2. If so, then the Interceptors go M3, M3b, M3i, M4, M8i.

2. Agree with all J2 Factories becoming Zero. Could we simply dedicate these factories to the Interceptor path to reflect this design branch?

3. The Jack's engines could go to Ha-34 but could we also split one of those over to George's engine to reflect more work there too

4. The M3b design as you list doesn't have an increase in armament, has more protection, reduced range, and better climb. Seems to be a fairly conservative move into the Interceptor Line.

5. Adavance George as described earlier?

6. Shinden at 5/45? Could that come forward or do you leave it where it is and have the player research to try and bring it forward?

1. The 3a is as historical and is still a successor to the M2. Players can skip or they jump straight to M5. The choice is there why deny it ? eg short term improvement but you have to convert many factories yourself or standardize and save HI.

2. Note they become Zero interceptros on the A6m3 path . Yes on the factories

3. No due to issues with the George engine. We are bringing the George forward which will bring the factories forward but you wont be able to build the Quanity straight away.

4. Yes the M3b is designed as a war time measure to handle interceptors being shot up by bombers defences focus is more on climb etc. Esp zeros will fair much worse than Jacks. Note it does have the 99-2 20mm cannons.

5. In next post

6. Yes any planes with canards is great historically its a 12/45 plane. It would benefit greatly from any work but its a pretty advanced plane so i took it as +6 months. There is also a jet version ...

I'm good with all this unless someone else has an issue.

[John 3rd]

ORIGINAL: bklooste

The carrier fighter line (conservative, emphazis on mass production)
A6M2
-> A6M3a (42/6) [Option] no auto upgrades of facilties
->A6M5 (42/10, no changes)
->A6M5b (43/3, no changes)
->A6M8 (was 43/8)  suggest available 43/6 with factories auto upgrading 43/10  , max speed 358. + 1 hex to all ranges.
->A6M9   44/4  auto upgrade refinement of the A6M8  Additional +1 hex to all ranges , +1 manuever at top 2 altitudes ,  max speed around 365, reflecting the overall design polish and improvements to the Kinsei engine, otherwise no changes) .Max load 1400.

Note engine factories dont upgrade eg no Sakei to Kinsei freebies.

FatR--You have thrown out a lot in this arena of conversation. Does this look OK to you?

[John 3rd]

ORIGINAL: PaxMondo

ORIGINAL: bklooste

ORIGINAL: John 3rd

If you did build a plant in Anshun Manchuria what would the impact be for those later models with the much larger/more powerful engines?  What would you do with final, late-war development and deployment of fighters?

The plant WAS built ( and there were deals done with Germa companies) its regarded as a bit of an engineering disaster ( PM /chemical engineering studies use it) as they didnt build a pilot plant and it was a disaster the lab knowledge was there but not the practical engineering /experience. A more successfull plant ( say like the ones they built in Germany but much smaller) would have massive impact , though its hard to quanitfy such a what if and would have used a lot of steel resources , note it is even strategically significant since then there would be much less need for the move South since Japans economy required a LOT less oil then germany. Anyway im just using it to produce some 100/130 octane fuel which can be blended so we can get over the Nk series engine issues.

While this accurate, the octane issue was mostly a different issue. As you suggest, IF Japan had been able to build this Fischer-Topsch unit it would have lessened some of their needs after the US embargo. The FT unit takes coal and converts it to a LNG type fuel which can either be burned as is or refined to other fuel products.

Japan's octane problem went back to the other point you made: steel production and quality. There two ways then to make high octane av gas: HCC (HydroCatalyticCracking) and Alkylation. They work oppositely, HCC cracks very heavy oil into lighter and Alky combine very light into heavier. HCC requires very high temp steels, Alky requires special acid resist steels. Both of which JAP struggled to make pre-war, and then during the war refineries are obvious and easy targets. Why they struggled is more difficult to pin-point. My opinion is that it was due to NIH/ego, but I have never read any supportable reasons for this nor really have I run across anyone elses.

If you assume that JAP was able resolve her octane problem (and GER struggled with this as well from '44 on due to allied bombing), then the later engines become far more reliable and come sooner (testing is more efficient).

How big of an assumption is this? Hard to say. From an engineering perspective, all of this was within their capability. The steel compositions required were well known and public domain, and pre-war the hardeners were readily accessible on the market. GER stockpiled these things for years prior to 1939.

When was this place originally constructed? If it fits into the Yamamoto timeline (considering his aeronautics pushing and desires) then we might seriously think on this. If it is a historical over-reach then we don't do it.

The other note is shouldn't this plant come in as a refinery? It wouldn't be an oil plant but a refinery--right?

[PaxMondo]

The FT plant would be an oil producer.  The HCC or Alky units are part of refineries.  Japan had both HCC and Alky units in operation throughout the war.  They just did not run well and they had more problems with repair, mostly due to steel quality and steel type issues.  They had to or they would not have had any av gas. 
 
The output of an Alky unit, in particular, can be upwards of 140 octane.  You then blend it with 80 octane straight gas to get your end octane you want.  Problems come when you don't have enough 140 octane OR you aren't attaining 140 octane due to operational issues.  Then you can't hit your production targets of octane numbers.  Then you have to decide 10 gals of 120 octane av gas or 20 gals of 112 octane av gas.  Guess which happened in wwii Japan a lot?  If you drive a performance car, you know what happens with running too low of octane ...
 
 

[bklooste]

They were built and work was going on in 39...though rather than spend lots with a German company in 39 they bought the rights and patents , reproduced it in the labs and went at it alone. Note the Shale oil plant while providing oil is not very high quality . The Fisher Tropsch plants can though it takes a lot of steal the Germans spent millions of tons of steel on their plants. Note the process is about 5 * as expensive ( in terms of power , coal and resources) as buying the oil from overseas it does deliver very high grade pure fuels.

Lurgi group plants
Nippon Lurgi Goshi KK was a Japanese company of the period involved in Japanese-German cooperation. The Lurgi AG German industrial group was a partner, and it was the Lurgi office in Tokyo. The Combined Intelligence Objectives Sub-committee of the United States and United Kingdom later investigated it.[1]

At the beginning of 1942 the Japanese acquired all the low temperature carbonization patents of Lurgi for Japan, Manchuria, and of China. The agreement gave the Japanese the right to construct plants and an exclusive use of patents. A flat payment of approximately 800,000 Reichsmark, was received from the Japanese, this sum being cleared through the German government. One of the aims was synthetic oil. For example, the South Sakhalin Mining and Railway Company plant at Naihoro/Oichai in Karafuto perhaps motivated the licensing: the southern Karafuto brown coal with a content of paraffin tar (about 15%), and low water content, was suitable for hydrogenation.

Mitsui Kosan KK Miiki (Ohmura) operated from about 1939. Lurgi AG installed an activated carbon plant to operate with the Fischer-Tropsch plant. Coke and water gas were produced, the coke ovens being built by Koppers.
The shale plant at Fushun (Japanese Bujum), Manchuria, was perhaps capable of annual production of 200,000 tons of shale oil. The Imperial Japanese Navy also had an interest there in producing some diesel oil and gasoline, in low amounts.
The Manshu Gosei Nenryo plant at Chinchow (Kinshu), was a Fischer-Tropsch plant producing about 30,000 tons per year, online from about 1940.
Near Beijing, in Hopei, the Kalgari factory was to develop the local bituminous coal. It could be used also for the Mengjiang coal of the Chahar-Suiyuan mines.
A planned gasification plant at Rumoe in Hokkaidô was apparently not built.
Chosen Sekitan KK at Eian was a small low temperature carbonization plant which was processed about 600 tons of coal per day. This plant yielded from 15,000 to 20,000 tons per annum of coal tar.

Anyway i will let Pax Mondo answer this line as he seems to know the chemical processes a lot better than me.

[bklooste]

ORIGINAL: PaxMondo

The FT plant would be an oil producer.  The HCC or Alky units are part of refineries.  Japan had both HCC and Alky units in operation throughout the war.  They just did not run well and they had more problems with repair, mostly due to steel quality and steel type issues.  They had to or they would not have had any av gas. 

The output of an Alky unit, in particular, can be upwards of 140 octane.  You then blend it with 80 octane straight gas to get your end octane you want.  Problems come when you don't have enough 140 octane OR you aren't attaining 140 octane due to operational issues.  Then you can't hit your production targets of octane numbers.  Then you have to decide 10 gals of 120 octane av gas or 20 gals of 112 octane av gas.  Guess which happened in wwii Japan a lot?  If you drive a performance car, you know what happens with running too low of octane ...

Also these larger refinaries were a major target, the US wisely went for which also adds to the difficulties. If teh B29s didnt come in in 1944 Japan would have had less issues with these more powerfull engines. I especially note the 601 type engine used in the Hien line.

Here is a great link german scientist note german 100 Octane was pretty close to 100/140.

http://www.fischer-tropsch.org/primary_ ... s_1697.htm

High Octane Number Fuels

Dr. Butefisch said that octanes were being made pre war at Leuna and Poelitz. In the former case isobutanol was the starting material

Production of aviation spirit at the start of the war was low because the Luftwaffe up to 1938 was not worried about high octane numbers; they were prepared to blend with benzol. When the Luftwaffe demanded higher octane numbers as a result of pressure from engine designers, iso-octane was made from isobutanol. The hydrogenation petrol had an octane number of 78-79 and with iso octane or alkylate addition, numbers of 102-104 were achieved. All the aviation gasolene came from black coal. The cost of iso-octane from isobutanol was said to be 80-90 pf. per kilo. In 1941 isobutane was dehydrogenated to isobutene, polymerised to iso-octene and hydrogenated. Later isobutene and butane were alkylated. There was, however, difficulty with supplying the isobutene. Leuna was the first to make alkylate.

Also germanies best Fuel was Synthetic and note both Germany and Japan quote different octane numbers eg German 100 C3 = US 150 Octane. Im not sure what Japanese 94 Octane was enriched.

By the early 1930s, automobile gasoline had an octane rating of 40 and aviation gasoline a rating of 75-80. Aviation gasoline with such high octane numbers could only be refined through a process of distillation of high-grade petroleum. Germany’s domestic oil was not of this quality. Only the additive tetra-ethyl lead could raise the octane to a maximum of 87. The license for the production of this additive was acquired in 1935 from the American holder of the patents, but without high-grade Romanian oil even this additive was not very effective. 100 octane fuel, designated either 'C-2' (natural) or 'C-3' (synthethic) was introduced in late 1939 with the Daimler-Benz DB 601N engine, used in certain of the Luftwaffe`s Bf 109E and Bf 109F single-engined fighters, Bf 110C twin-engined fighters, and several bomber types. Some later combat types, most notably the BMW 801D-powered Fw 190A, F and G series, and later war Bf 109G and K models, used C-3 as well. The nominally 87 octane aviation fuel designated 'B-4' was produced in parallel during the war.

In the United States the oil was not "as good", and the oil industry had to invest heavily in various expensive boosting systems. This turned out to have benefits: the US industry started delivering fuels of increasing octane ratings by adding more of the boosting agents, and the infrastructure was in place for a post-war octane-agents additive industry. Good crude oil was no longer a factor during wartime, and by war's end American aviation fuel was commonly 130 octane, and 150 octane was available in limited quantities for fighters from mid-1944. This high octane could easily be used in existing engines to deliver much more power by increasing the pressure delivered by the superchargers.

In late 1942, the Germans increased the octane rating of their high-grade 'C-3' aviation fuel to 150 octane. The relative volumes of production of the two grades B-4 and C-3 cannot be accurately given, but in the last war years perhaps two-thirds of the total was C-3. Every effort was being made toward the end of the war to increase isoparaffin production; more isoparaffin meant more C-3 available for fighter plane use.

A common misconception exists concerning wartime fuel octane numbers. There are two octane numbers for each fuel, one for lean mix and one for rich mix, rich being greater. The misunderstanding that German fuels had a lower octane number (and thus a poorer quality) arose because the Germans quoted the lean mix octane number for their fuels while the Allies quoted the rich mix number. Standard German high-grade 'C-3' aviation fuel used in the later part of the war had lean/rich octane numbers of 100/130. The Germans listed this as a 100 octane fuel, the Allies as 130 octane.

[John 3rd]

OK.  Looks like a possibility.  Thanks Pax and BK!  What would the net impact of this be if we went along with the plant being up-and-running?
 
 

[mikemike]

I've missed the last few days of posts in this thread, so my comments are a bit late.

Some things I got from the book I quoted (I left out a lot of the text):

The switch of the Zero engine from Sakae to Kinsei was not primarily prompted by expected better performance (although that must have been a welcome effect), but by fears that Sakae production might not be up to delivering the needed numbers. The Navy had no such fears concerning Kinsei supply for the whole Zero output, so I think limiting Kinsei production so not all Zeros can be Kinsei-powered would be quite counterfactual.

The A7M was started in April 1942 because the IJNAF was aware that the USA was producing planes of superior performance (the discussion expressly mentions the P-38) and that further performance improvements would be probable so they foresaw that the Zero would become outclassed a few years down the line and they'd need something a lot better at that point. The author doesn't say so outright, but it seems Horikoshi wanted the MK9 (Ha-43) because he trusted Mitsubishi more to come up with the goods than Nakajima, but the Navy was fixated on the Homare.

Mitsubishi's Nagoya works also had design responsibility for the Betty and its successor, for the Rufe, and for a 17-shi interceptor. These were all projects not worked on by the Horikoshi design group.

Now some remarks of my own:

The designers estimated the A7M would need at least 2000 HP to meet specifications but when the aircraft was tested with the 2000 HP Homare the performance wasn't better than the A6M5, so finally the MK9 was used which got the aircraft up to 390 mph. Less power would have meant even worse performance, and that would have become clear at the preliminary design stage where the fundamental parameters of the design are established. bklooste has quoted power/weight ratio in his defence of the Kinsei A7M, but p/w ratio never tells all the story (if P/W ratio was the only parameter influencing speed, the Harrier with its thrust/weight ratio of greater than 1 would be faster than the F-104 or the F-4, both of which had far worse T/W), there is also drag, and as you know, the Japanese put great importance on the agility of their fighters, more agility means more lift, and more lift means more induced drag, there is no escaping that. From another angle, if you have two planes with the same engine, the one that is far heavier and bigger will of course have a worse performance.

The Kasei was really too big for a plane the size of the Jack, but the A7M was a big plane, and the Ha-43 was a big engine, too. The same goes for the Ha-104 which had a cooling fan like the BMW 801 and could have been put in a Fw-190-like low-drag installation.

One of the problems the Japanese had was duplication of effort in the engine sector. Mitsubishi built the Kasei (1800-1860 HP), the Ha-104 (1900-2000 HP), the MK9 (Ha-43, 2200 HP), the Ha-214 (2400 HP), while Nakajima had the Mamoru (1800 HP), the Homare (1900-2000 HP), the Ha-44 (2400 HP). Now it's interesting that Nakajima had in this high-power lineup one complete flop (the Mamoru) and one troubled engine (the Homare), while Mitsubishi's engines were apparently reliable, yet everyone used the Homare, while the equivalent Ha-104 (available early in 1943) was used only on the Ki-67 (which does't seem to have had engine troubles). Either Nakajima had very effective salesmen or they had better connections to the powers-that-be.

[bklooste]

ORIGINAL: mikemike

I've missed the last few days of posts in this thread, so my comments are a bit late.

Some things I got from the book I quoted (I left out a lot of the text):

The switch of the Zero engine from Sakae to Kinsei was not primarily prompted by expected better performance (although that must have been a welcome effect), but by fears that Sakae production might not be up to delivering the needed numbers. The Navy had no such fears concerning Kinsei supply for the whole Zero output, so I think limiting Kinsei production so not all Zeros can be Kinsei-powered would be quite counterfactual.

This is actually shown in the stats there is not a lot of difference between the A6M8 vs A6M5. However the Kinsei does give better climb speed due to power to weight.

Wide spread adoption of the Kinsei 62 in 43 or even late 42 would have certainly been much better. That said there must have been some issues ( maybe cost ?) as the G3 was upgraded with a kinsei 5x series in early 43 when the 62 was being provided for the Dinah III.

With regard to output there is quite a bit of demand for the Kinsei , i have no doubt that the engine can be produced in numbers and this is shown by an early date 1/43. However producing a large amount of Kinsei 62 will take time , you could use an earlier Kinsei like the 50 series but performance would be below an M5.

The A7M was started in April 1942 because the IJNAF was aware that the USA was producing planes of superior performance (the discussion expressly mentions the P-38) and that further performance improvements would be probable so they foresaw that the Zero would become outclassed a few years down the line and they'd need something a lot better at that point. The author doesn't say so outright, but it seems Horikoshi wanted the MK9 (Ha-43) because he trusted Mitsubishi more to come up with the goods than Nakajima, but the Navy was fixated on the Homare.

Mitsubishi's Nagoya works also had design responsibility for the Betty and its successor, for the Rufe, and for a 17-shi interceptor. These were all projects not worked on by the Horikoshi design group.

Now some remarks of my own:

The designers estimated the A7M would need at least 2000 HP to meet specifications but when the aircraft was tested with the 2000 HP Homare the performance wasn't better than the A6M5, so finally the MK9 was used which got the aircraft up to 390 mph. Less power would have meant even worse performance, and that would have become clear at the preliminary design stage where the fundamental parameters of the design are established. bklooste has quoted power/weight ratio in his defence of the Kinsei A7M, but p/w ratio never tells all the story (if P/W ratio was the only parameter influencing speed, the Harrier with its thrust/weight ratio of greater than 1 would be faster than the F-104 or the F-4, both of which had far worse T/W), there is also drag, and as you know, the Japanese put great importance on the agility of their fighters, more agility means more lift, and more lift means more induced drag, there is no escaping that. From another angle, if you have two planes with the same engine, the one that is far heavier and bigger will of course have a worse performance.

The Kasei was really too big for a plane the size of the Jack, but the A7M was a big plane, and the Ha-43 was a big engine, too. The same goes for the Ha-104 which had a cooling fan like the BMW 801 and could have been put in a Fw-190-like low-drag installation.

One of the problems the Japanese had was duplication of effort in the engine sector. Mitsubishi built the Kasei (1800-1860 HP), the Ha-104 (1900-2000 HP), the MK9 (Ha-43, 2200 HP), the Ha-214 (2400 HP), while Nakajima had the Mamoru (1800 HP), the Homare (1900-2000 HP), the Ha-44 (2400 HP). Now it's interesting that Nakajima had in this high-power lineup one complete flop (the Mamoru) and one troubled engine (the Homare), while Mitsubishi's engines were apparently reliable, yet everyone used the Homare, while the equivalent Ha-104 (available early in 1943) was used only on the Ki-67 (which does't seem to have had engine troubles). Either Nakajima had very effective salesmen or they had better connections to the powers-that-be.

Yes the Mitusbishi engines wer reliable the Homares were a world leading design and were certainly pushing the limits

[John 3rd]

It would APPEAR that we are locked in now with the new warships and aircraft tracks.  Does any of the contributors have a final thing to say before we shift from the research, debate, and decision process to the actual creation of the Mod?  I'll leave this question open for a few hours...
 

[ny59giants]

Theme to Jeopardy plays softly in the background.

[John 3rd]

New Thread has been started as the Reluctant Admiral.