Yamato logic for single-engined, single seat fighter

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Admiral Beez said:
Yes, that's the very foundation of the thread. Japan pursues a 2000hp engine.
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So the US needed the honking big R-2800 to get an engine in the 2000hp class, using 100/130 fuel. So with Japan having lower octane fuel (91, or what was their standard fuel?), they'd need an even bigger and honkier engine to make up for the lack of high octane fuel. Say, adding 20% displacement to the R-2800 works out to about 55L. Now due to not being able to boost as high as the US engine, they can get away with somewhat lighter construction so the weight penalty could be lower than you'd get by just scaling up the R-2800? Though frontal area would still be bigger than the equally powerful R-2800. Could it still be good enough to power a competitive heavy fighter?

(Yes, the Homare went in the other direction, but given the reported issues with it, unclear whether even a massive program could have resulted in a reliable Homare in 1941.)
 
Perhaps a Japanese made engine similar to the Napier Sabre, but with poppet valves? I am not sure, but I think during development the Sabre was rated on 87/91 grade fuel, putting out about 1800-2000 BHP.

Admittedly, it is a complicated engine, but the Japanese did not seem to have a problem developing good engines when they were not at war with the US/UK/USSR. If they started about the same time Napier did (1935) on the Sabre?
 
z42 said:
So the US needed the honking big R-2800 to get an engine in the 2000hp class, using 100/130 fuel. So with Japan having lower octane fuel…
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I expect Japan would move to high octane fuel. Not an easy task, but neither was Yamato. This a the IJAAF's top project, so they'll allocate resources accordingly.
 
Admiral Beez said:
As there was with Yamato. Heavens, this forum needs a rule, no kneejerk contrarianism without a proffered solution to whatever the challenge is.
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Wait, just because someone points out a potential difficulty, that renders them a "knee-jerk contrarian" to you? Simply labeling and discarding a point without addressing it is not a discussion. Perhaps you could explain where that funding is going to come from given Japanese strategic priorities and military needs?
 
Admiral Beez said:
I expect Japan would move to high octane fuel. Not an easy task, but neither was Yamato. This a the IJAAF's top project, so they'll allocate resources accordingly.
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Japan had a steel industry. Japan had a ship building industry. Japan had gun making and armor industries.
Japan had been working on these industries since before the Russo-Japanese war of 1905.
Japan ha planned to build 4 battlecruisers with eight 18in guns in the 1920 but stopped due to the Washington treaty.

Number 13-class battleship - Wikipedia

en.wikipedia.org


47,500 tons (normal) Full load would have put them in the mid 50s. Slips had been assigned but actual construction had not started. They were the planned additions to the 8-8 plan of large battle ships and battle cruisers to counter the US South Dakota class of 1918-19. Twelve 16in guns and the Lexington class battlecruisers.

The Yamoto's were a huge effort, but they didn't require a big change in technology. Changes in scale yes but the Japanese had already drawn the plans for and started construction of ships that bridged the gap from the Nagato's to the Yamoto's. Keeping them secret was trick though.

100/130 fuel depends on a petrochemical industry that Japan did not have.
The US barely had the needed industry in 1939-40.
Knowledge in the lab is not the only problem.
The US had to balance the need for refining oil and related compounds with the need for steel for other construction and even ship building. A large refinery could take 10-20,000 tons of high grade steel. 100/130 fuel needs the aromatic compounds. You can switch them around but you need over 10% and a bit less than 20% aromatics or you don't have 100/130. Maybe you have 100/108 or 97/110 or something else.
Labs tested fuels with over 6cc of lead per gallon in the lab. Problem is that they could only use around 4.6cc and even with better spark plug technology they had a lot problems with lead fouling the Spark plugs and with deposits screwing up the exhaust valves.
Japanese use of water injection was actually a pretty ingenious work around.

For the Japanese to develop 100/130 as apposed to even 96 or 98/108 was calling for Japan to develop fuel and an industry that the Britain and the Us did not have in 1939-40.
 
The crucial ingredient behind the US being able to produce 100/130 fuel in volume was the Houdry process. Pilot plant went online in 1937.

Houdry Process for Catalytic Cracking - National Historic Chemical Landmark - American Chemical Society

American Chemical Society: Chemistry for Life.
www.acs.org

Hard to see how Japan could have replicated that and rolled it out to the various refineries both at home and in conquered Borneo and DEI in time to make a difference during WWII.

Germany was able to produce limited quantities of their C3 fuel, roughly similar to 100/130, though at eye-watering cost. In any case, Japan didn't have a synthetic fuel industry, so the point is moot.
 
Thumpalumpacus said:
Wait, just because someone points out a potential difficulty, that renders them a "knee-jerk contrarian" to you?
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No, it's not you or me, but the nature of how these discussion forums work. Have a look at this entire forum, have you ever seen a post where someone has suggested anything where replies are for the most part building up or expanding upon the idea. No, what we get instead is a steaming pile of replies on why whatever is proposed would, could or should not have been feasible. Perhaps that the nature of the internet, but it saddens me a little that this is where we always end up. This is something I've worked on in my own personal relationships, where I try not to play the contrarian on ideas or suggestions from family and friends - it's easy to tell our kids, spouses, etc. why something is a bad idea or wouldn't work, but more of a challenge to build it up, especially if we disagree with it. Canadian Thanksgiving is this weekend, and once the wine flows the extended family dinner can turn into a nightmare of contrarianism - so I make a point of not playing it. Look at my history of replies here on WW2aircraft.net and you'll see that I very rarely posit why an idea won't work, but instead I enjoy trying to sort out (without aliens or foresight) how it could be made to work, sometimes looking at how limited resources can be reallocated to get there. That's what I always, foolishly I admit, hope to find here: replies to ideas that present both the challenges AND suggest the solutions. My anti-contrarianism approach doesn't work for others, and I sense some are almost psychologically triggered, trolling the What-If forums for that "gotcha!" moment and dopamine hit to tell us all why an idea is shite.
 
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Admiral Beez said:
Have a look at this entire forum, have you ever seen a post where someone has suggested anything where replies are for the most part building up or expanding upon the idea.
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There have been "what-ifs" that I've replied to positively. Your accusation of my being a knee-jerk contrarian is not well-founded.
 
There were a lot of things done in WW II (and other wars) that were dumb. A lot of it was tactics/doctrine which at times influenced the actual hardware purchased.
However there were a lot of smart people working on things like hardware. (I will include fuel as hardware as apposed calling it a tactic or doctrine).
A problem with a lot of "what ifs" is that they call not for change in doctrine/tactics but for changes in technology or for changes in physical plant (number or size of factories).

I am very critical of some of the British army policies/tactics/doctrine of the late 30s and early 40s. This lead to building thousands of useless tanks (panic buying) and very less than good designs. The whole tanks should not have HE cannon projectiles thing. There was no reason whatsoever for this. They knew how to make HE shells of the needed size, they were making HE projectiles of the right size, they just didn't give them to tanks.

This is a bit different than calling for hypothetical engines using hypothetical fuel in a time period several years before such things existed. Or if they did exist (2000hp engine in 1940) they were very large and not very good. Wright took a look at their existing R-3350 engine and pretty much tossed it out and started over keeping the same bore and stroke.
Waving hands to say somebody could have done it if they just exerted the will and effort is not really overcoming the obstructionist points.

I really don't know what the problems were with Japanese engines in the late 30s or 1940. They were not really up to the US and British (?) standards although a few were close. Japanese just got the Kasai engine into production in 1940 which was rather comparable to the Wright R-2600 A series. although a bit lighter.
Japan did a lot of good things but a real problem is just size. They didn't have the same number of engineers and technical people just because of their smaller population and industrial base.
SO in this case we have to believe that steel workers, shipyard workers and their engineering staff can be shifted over to aircraft engines and petrochemical engineering and refining construction?

We know that the Yamato was a mistake but knowing it then is a harder sell. The Japanese requirements for the Val dive bomber were issued in 1936 when the plans for the Yamato were being worked on (plans for a battleship often took several years) and the D3A prototype did not fly until Dec 1937 (with a 710hp engine) and Yamato was ordered in March 1937 and laid down in Nov 1937. Chances of even 200 D3As sinking the Yamato were about zero. Beat the crap out of the upper superstructure and deck yes. 250kg bombs are not battleship killers.

Getting back to Japanese engines, the Kinsei engine used in the D3A didn't get a two speed supercharger until the summer of 1942.
There were a lot of things the Japanese might have been able to do to improve their aircraft in 1941-42-43. Trying for a 2000hp engine was not one of them. Nothing against the Japanese here, Germany didn't do it in 1941/42. Britain only had the Sabre and in 1941-2 it was pretty much a failure. The Americans only had the R-2800. The Americans had several failures sitting the workshops and the R-3350s used in the B-29 was a pretty sorry piece of work even in 1944.
 
The Mitsubishi Zero was reasonably well armed. Based on Emmanuel Gustin's website, the A6M2's 20mm cannon and 7.7mm machine guns delivered 2.62kg/s. The six .50 machine guns on Corsairs, Hellcats, most P40s, and P51Ds delivered 3.46kg/s. The four machine gun P51B and Cs did 2.31kg/s
 
This is true, but the F6F and F4U would deliver that weight of fire for around 30 seconds, not 6-7 seconds.
P-40E-N could deliver for 18 seconds but often carried a bit less ammo.
6 gun P-51s didn't carry the same amount of ammo per gun but even the least amount of ammo was good for about 18 seconds.

The US .50 cal was easier to defection shoot with. Not that it was easy to deflection shot, just that the .50 wasn't as hard.
 
Howard Gibson said:
Given the actual damage done by the Yamato and Mushashi in combat, you have to ask what the Japanese could have done if they had not designed and built them.
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Built a bunch of convoy escorts?
Figured out that a bunch of subs that could attack Allied supply ships or raw material transport may have been a good idea?
Heck, build more tankers to get the captured oil back to Japan.

And I have not even crossed over going from navy and ship building to aircraft engine building and petrochemical engineering

There is a bunch of things we can go back and figure out where the resources could have been better spent.
 
The Pladjoe Refinery at Palembang, Sumatra was captured virtually intact by the Japanese in Feb 1942. It was capable of producing 2,500 barrels of 100 octane aviation gasoline (with the addition of 4cc of tetra-ethyl lead per US gal) daily (912,000 barrels per year) as well as the same quantity of 90 octane (with the addition of 3.5cc per US gal).

The Soengaigerong Refinery also at Palembang, Sumatra was capable of producing 420,000 barrels of 100 octane and 360,000 barrels of 90 octane per year pre-war as well as lesser grades. Although completely destroyed in Feb 1942 it was restored to about 30% of its pre-war capacity by the Japanese.

The Pankalan Brandan refinery in northern Sumatra was capable of producing 80 (with the addition of 3cc tetra-ethyl lead ) & 91 octane (with the addiition of 4.6cc) fuels pre-war. While some damage and destruction was carried out in 1942 the Japanese got the plant up and running again.

This comes from US reports on the oil facilities in these locations produced in 1944/45. In addition I believe that the Pandansari Refinery at Balikpapan (1 of 2 in that location), the most modern refinery in the DEI at the start of the war also had the capability to produce 100 octane. While badly damaged in 1942 the Japanese had it back in production in 1943.
 
This sounds like they were producing two different base stocks, you don't get 10 points more octane with just 0.5 cc's of lead.
You also need spark plugs that will handle 4cc's of lead. Most engines and spark plugs with handle 3 CCs and under.

The Japanese may have need the better base stock fuel to blend with lower grades to get more 91-93 octane fuel?
In most fuels you get a smaller increase in octane rating per CC of lead. Going from O CCs of lead to I.0 CC of lead gets a substantial increase, going from 5cc to 6 ccs gets small increase. For the US 4.6 CCs was limit.
Also higher octane base stocks get a higher percentage increase per CC of lead than lower octane base stocks.

Getting much above 100 octane gets tricky. Paraffins react well to lead. Olefins, naphthenes and aromatics respond less to lead.
100/130 means 100 octane(PN) when running lean and 130 (PN) when running rich. But you need the Olefins, naphthenes and aromatics in order to get the rich response but you can't use too much or the BTUs per gallon goes down and you get a bit less range when cruising.
 
z42 said:
Germany was able to produce limited quantities of their C3 fuel, roughly similar to 100/130, though at eye-watering cost. In any case, Japan didn't have a synthetic fuel industry, so the point is moot.
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Japan did have a synthetic fuel industry. It might not have been large in the overall scheme of things but it did exist. From the Combined Fleet site
"Synthetic Oil


In the 1920s, the IJN undertook experimentation with synthetic fuels. Synthetic oil was produced from domestic coal, coal tar and oil shale via an industrial chemical process and refined into gasoline and other petroleum products. The bulk of the coal came from domestic mining. While the United States naval blockade and mining operations were very effective in preventing oil shipments from reaching Japan, synthetic oil could be produced on the Home Islands.

Despite production problems significant quantities of synthetic oil were produced. Synthetic oil production from May to August 1945 was 21,845,250 gallons.

The Ube Coal Liquifaction Company in Ube, Japan was capable of processing coal into hydrocarbon stock destined for conversion into gasoline and other needed products. The company was credited with the capacity to produce 475,000 barrels of synthetic oil, about 1/3 of Japanese home-island productlon. The plant most probably obtained coal from undersea mines located about a mile south. "

 
Hi
Japan may have had a smaller population than the USA but it was large compared with many European countries, it was nearly as large as Germany (+Austria) and much larger than the UK, see below with figures from 'The Air War 1939-1945' by R J Overy, page 151:


Mike
 
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