Twin-Boom Superplanes... With A Twist!: Mansyu Ki-98 & Mitsubishi J4M

In this video, we talk about two twin-boom pusher-prop plane designs from late World War 2 Imperial Japan, in the Mansyu Ki-98 and Mitsubishi J4M. We first start by talking about radial engines, how they typically work, and what their advantages and disadvantages are. Then we go into the war situation of Japan from mid-WW2 onward, with mainland Japan increasingly coming under bomber attack. We then look at the Ki-98, its early beginning as a ground attacker, and how the war situation led to it changing to a high altitude fighter and interceptor.
We also look at a similar, almost carbon-copy in the J4M that was intended to fill the same purpose. We talk about their projected incredibly high top speeds and how they had an odd design choice in using an air-cooled radial engine buried behind the cockpit in the body. We talk about why this was an odd choice and how they went about accounting for it. We end by talking about how even if these planes made it to combat, they wouldn't have changed anything about the war.

[@powellmountainmike8853]

Do not confuse the RADIAL engine with the ROTARY engine. They look similar when they are not running, but VERY different when they are. With the RADIAL engine, the cylinders and crank case remain stationary, only the crankshaft rotates. They are mostly all 4 cycle engines also. With the ROTARY engine, as the name implies, the whole crankcase and cylinders rotate along with the propeller, and the CRANKSHAFT is stationary and affixed to the body of the airplane. The rotary engines were also mostly 2 stroke. They were popular in World War 1. By World War 2, they were considered obsolete, and radial engines had entirely replaced them except on some very old planes which retained their original engines.

[@johnedwards3621]

Radial engine cyclinders have fixed positions that radiate from the center of a crankshaft that turns within the engine.. Rotary engine cyclinders, and the propeller, rotate around a crankshaft that is firmly fixed to the enrire aircraft; The propeller of a rotory engine is attached to the engine. The propeller and engine rotate as one assembly. Both provide better cooling than inline cylinder engines. The rotory engine has wicked gyroscopic precession that requires very different piloting skills compared to other airplanes.

[@rbilleaud]

I don't think anyone is confused by that, at least on this channel. Interesting tidbit on rotary engines. Early model Mazda automobiles used a rotary engine type known as the Wankel. Little bit different obviously from aero engines, but I found working on them fascinating.

[@powellmountainmike8853]

@@rbilleaud The Wankel engine, although termed a "rotary" engine, is an entirely different principle from the rotary aero engines used in the First World War. Those engines had pistons and cylinders, all of which, along with the crankcase, rotated and were attached to the propeller. The crankshaft was fixed to the aircraft's body. The Wankel engine has a fixed body. What rotates is a triangular piece inside geared to the power output shaft. There are no cylinders, per se. It is entirely different. The only similarity is the term "rotary."

[@roryhennessey8836]

​@powellmountainmike8853 that's what I kept thinking of. I didn't know there was two types of rotary engines

[@brianb-p6586]

@@rbilleaud Mazda used the Wankel design of rotary-piston engine for decades (1967 - 2012, plus again starting in 2023), not in its earliest cars, and not just in early models.

[@ethanmckinney203]

The FW190 had just such a cooling fan at the front of its radial, which allowed a tighter cowling with a large spinner. While it ate up significant horsepower, the net benefit was large. The Japanese were probably aware of the design by the time they started work on these aircraft.

[@Teh0X]

They used cooling fan like that in J2M.

[@enscroggs]

The photo of Ha-211 RU engine shows a cooling fan quite similar to the fan used by the BMW 801 installed on the propeller shaft.

[@fazole]

The Germans traded technology for needed resources like metals.

[@ThatsMrPencilneck2U]

@@enscroggs I thought the picture he showed was a BMW 801! I guess there are only so many ways to design a ducted fan.

[@webtoedman]

The cooling air has quite a lot of energy after picking up heAt from the engine. With the right ducting, it can provide a small but useful but useful amount of thrust, which may have been part of the reasoning behind using this design.

[@enscroggs]

Convergent evolution also demonstrates the same principle as "convergent engineering". The laws of nature tend to winnow out the most imaginative ideas from the most effective ones.

[@ashbirk4681]

I’ve been saying that wartime military development strongly resembles radiated adaptation, it’s an interesting phenomenon

[@jamiejones7325]

Great point. I’m an evolutionary biologist, but husband in military intel and sims. Ancestors in opposing militaries lol. But ‘convergent evolution’ is fascinating. Hopefully you men, 90% of all geniuses will always be you as 90% of retarded, autism for instance, to cure aging and diseases like cancer, Alzheimer’s etc. The same imagination, scientific method etc, you would be surprised his many cures for ‘A’ actually resulted from research on ‘Z’. Please boys, keep up your interests and ideas.

[@enscroggs]

@@ashbirk4681 Very true. Furthermore, these wartime developments often carry on less than optimal features for similar reasons seen in biological evolution. Whales drive themselves through the water by stroking their tail flukes vertically, whereas nearly all fish and the extinct Ichthyosaurs employ a horizontal side-to-side motion. Hydrodynamic principles suggest fish are more efficient swimmers on account of their horizontal tail motion. ( The flatfish -- flounders, sole, halibut -- are exceptions as they have traded efficiency for stealth.) Whales, however, have retained a spinal column evolved for fast running on land which doesn't really benefit their totally aquatic lifestyles. The overwhelming trend toward air-cooled radial engines in the Imperial Japanese forces can be viewed in the same light as the mammalian spine.

[@brucebartup6161]

I must say, I think you may all be al talking balderdash. Evolution is a matter of random change, blind luck and trial and error. And that is conceding that evolution has a purpose - long term survival. of many species, In fact it has no purpose at all Engineering design is a matter of ingenuity in service of some Human goal . It is purposive. deliberate and goal driven. In war of course each side develops new machinery, tactics; exploits opportunities and defends against new threats existing platforms will change To cite some even clearer examples: Would you say that a fox is a better inhabitant of English woodland scavenger/hunter niche because its teeth are more evolved than simpler badger's teeth in other words the fox has passed through more near extinction events connected to tooth construction? Would you say that a Spitfire mk XIX is a better design than a Hurricane Mk III one as a fighter thee other as a fighter bomber - just because 19 is bigger than 3? oohh dratt. I think I get it now,, you aren't saying they are the same kind of thing. You you're' saying they are analogous. Right? Because there's nothing whatever the matter with whales tails. From Blues to Orcas they were all doing just fine until humans showed up. No doubt some were on the edge of extinction. There always are some like that , without that preessre there woiuld be no evoliution and no us. And I take the point about adaptive evolution though beyond the finches i cant think of a good example

[@uingaeoc3905]

The only Pusher Prop Twin Boom fighter in WW2 period to make production and service was the Swedish Saab 21. It was later converted to carry a jet engine as the Saab 21-R as its configuration was so similar to the DH Vampire and used the same DH Goblin engine.

[@briancavanagh7048]

Surprised you mentioned a French pusher before a British aircraft. There was a many paper projects and some actual airframes- Vickers Type 161, Boulton Paul P99 & P100, Gloster F18/37.

[@SCjunk]

6:40 photo shows the Ki 94 mockup a push pull design similar to the Dornier Piefel D335

[@blueinmotion9438]

Same thought here. It looks like a push/pull design. And it's Pfeil (Arrow), ;)

[@edrosenquist6541]

STREET FIGHTER!!!! YEA!!! Awesome analogy!!! And a very cool plane that I've never heard of. Thank you.

[@HootOwl513]

Your mockup at frame [10:29] is a Pusher-Puller. The two aircraft you're high-lighting are Pushers.

[@johnniewoodard648]

11:36 The Netherlands S-21, Would love to see a video covering that design. I do realize that info on it may be lacking.

[@retepeyahaled2961]

The pictured mock up of the Mansyu seems to have a pusher propellor and a puller propellor?

[@Teh0X]

That's Ki-94-I.

[@jonniiinferno9098]

@@Teh0X - maybe so - but it was included with this video - which would obviously be confusing - specially when one had never heard of the KI-94-I

[@Teh0X]

@@jonniiinferno9098 No doubt about it. Certainly a mistake.

[@obsidianjane4413]

@@jonniiinferno9098 Should have been included in this essay since it was one of the candidate bids for their "wunderwaffesu" fighter. Perhaps he couldn't find enough info or cut it for time, but the pic snuck in?

[@nor0845]

The Mitsubishi looks similar to a prop version of the DH Vampire. Interesting vid. Thank you for posting.

[@patrickwentz8413]

But did if fight Godzilla like the Kyushu J7W Shinden?

[@LastGoatKnight]

Nope

[@davidhayes7596]

This would make a great kit plane project.

[@just_one_opinion]

Great Show.

[@williamromine5715]

I did enjoy the video, and I learned something at the same time. Having been born in January of 1942, I have always been interested in the Second World War, and it is gratifying to learn something new about the War. Thank you.

[@colintwyning9614]

Fascinating video. Thank you

[@steveshoemaker6347]

Thanks for the very interesting war bird video..... Old F-4 II Shoe🇺🇸

[@neiloflongbeck5705]

Isn't that a Sopwith Camel at the 0:44 mark within rotary engine?

[@Easy-Eight]

Yes. The author does not know the difference between a rotary (fixed crankshaft) and a radial (moving crankshaft).

[@martkbanjoboy8853]

Did the Crntral Powers use rotary engines on warplanes? It might have been a spectacular episode to attack such a warplane with an S.P.A.D. It's 37mm would probably make short work with one good hit on the engine spinning at high rpm!!

[@neiloflongbeck5705]

@@martkbanjoboy8853 yes, they did. The Fokker Eindekker and Dreidekker both had rotary engines, to name but two.

[@gandalf97]

the engine configuration reminds me of the italian p.119, it wasn't a twin boom but the engine location and type was exactly the same. they actually test fly it and guess what, had cooling problems, but it still performed decently well, before it had a problem when landing because of the landing gear, sadly it was not repaired because of the armistice. the chubby fuselage gave the designers a lot of room to put fuel and had a very high range compared to other italian planes

[@volters9561]

It didn't have a fan inside, and propeller was in front of the plane

[@Catsrule1132]

Could you do a video on some if those high efficiency hoten gliders or their super sonic concepts

[@harrikeinonen7576]

I’m not sure that the picture of the KI98 mockup is right. There are a couple of significant differences: the tail assembly is a different configuration with a low set tailplane and the fin shape is also different. But the biggest difference is that the mockup has two engines. One in the back and one in the front. It is in fact a photo of the Tachikawa KI94.

[@wormyboot]

I've always been baffled and fascinated by rotary engines. I don't understand how fuel moves from a fixed gas tank to a spinning set of cylinders. Absolute magic to me.

[@volters9561]

The crankshaft is hollow. And fuel goes thru there.

[@808bigisland]

Applies to a rotating engine - fuel is fed through the hollow crank - fixed solidly to the aircraft. Radial engines work like your car-engine and only the outputshaft rotates.

[@iskandartaib]

It follows that the conrods are also hollow, and the fuel-air mixture comes up through the middle of the piston? I think there's a spring loaded poppet valve in the piston crown.

[@obsidianjane4413]

Many were 2 strokes, or used the principle of passing the mixed fuel/air charge thru the crankcase to be drawn into the pistons from ports.

[@iskandartaib]

@@obsidianjane4413 I don't recall coming across any that were two strokes..

[@stephengardiner9867]

Radial and Rotary engines are similar in some respects but VERY different in operation. They do share air cooling as a common feature. Rotary engines were widespread during WWI but were soon replaced by the Radial shortly after.

[@GeorgeRuffner-iy7bm]

I definitely learned something from this video. Thanks. 🙈🙉🙊 😎 🇺🇸

[@johnforsyth7987]

Thank you for another informative entertaining video.

[@jeffapplewhite5981]

Never saw these planes. Good information. Thanks

[@drfill9210]

Been thinking about this. If the intake fan worked, it would also have mitigated boundary layer resistance... it might have been super slippery

[@stevenborham1584]

Yes and the shutters at the rear could have been tuned to produce a net thrust like in a P-51 Mustang. With propeller cuffs the whole design could have become very efficient.

[@drfill9210]

@@stevenborham1584 they were already doing that to late model zeroes

[@bigblue6917]

Thanks for the video. Having a long standing interest in military aviation I have come across these two aircraft but this has added much needed detail.

[@shaunmaree6493]

Looks like a propeller driven De havilland Vampire

[@kronop8884]

Or SAAB J21

[@speedfinder1]

It is possible that the hot air being expelled from the back, may even have provided some element of thrust. (The Meredith Effect.) It would depend on the integrity of the cowling but as the hot air would have expanded it could very well have had some measurable effect. This could have gone some way to balancing the engine power lost in driving the fan.🤔. An example of this system in action, can be seen in the P51 Mustangs cooling system.

[@kiwijonowilson]

These are great looking aircraft (if they would have ended up looking like that). Kind of looks a bit like a propeller version of a Vampire.

[@alexprost7505]

11:39 what exaclly names this s21 ? You have video about him?

[@jonniiinferno9098]

at 6:41 - that mock up looks like it has a prop in front as well as in the rear...

[@SomeOrdinaryJanitor]

slight side note, that mock up you showed at 11:00 is of the Tachikawa Ki-94-I, not of the Mansyu Ki-98

[@salvagedb2470]

Cool designs but with the Pusher prop , begs the Question how did the Pilot get out without being Diced ? ..Good vid.

[@Teh0X]

Twin-engine Ki-83 also used Ha-43 engine.

[@brucewelty7684]

Do pushers help with elevator control?

[@cabanford]

They fan in front of the radial is what the FW 190 used... HP of the engine is also similar - was the engine a copy of the BMW?

[@firstcynic92]

The J4M reminds me of Thunderbird 2.

[@Nightdare]

My thoughts exactly

[@stevenborham1584]

The J4m is a super sleek ship. It would have been better in the Saab 21 niche than the Saab 21 itself. The mid-wing would have reduced the propeller vibration experienced by the Kyushu J7W (less downwash and off-set masking effect). The large passive cooling air inlets would have helped its engine driven fan immensely simultaneousely creating a kind of 'Dynamic soaring' like effect at the rear fuselage. However it would have ultimately needed more power for its design weight, say the likes of the R-3350 size and +2,500hp as she is a fairly big bird.

[@douglasfur3808]

The SAAB 21 deserves more notice in that it was in service for ~4 years. However it had a water cooled engine. It was also later converted to a jet engine design.

[@demonicusa.k.a.theblindguy3929]

Please sir . . . Can I have some more? On the J7W.

[@ukulelemikeleii]

The ki 61 had a water cooled engine. Maybe they could have used that motor for these projects? Souped it up a little with a hot cam and fuel injection?

[@glitch9211]

Very cool video as I'd never heard of either aircraft (yes, I did learn something). As a side note, there's a big difference between a radial engine and a rotary engine, as shown in some of the photos early in the video and used extensively in early fighter aircraft.

[@user-dj9nc8ge8k]

Ki⭕️ Ha⭕️ 👍 Thank you from Japan

[@DaremoKamen]

The biggest problem the Japanese had with engines was that their fuel was lower octane. It was because they had much less oil to start with, so if they refined it to octane levels the Allies used they wouldn't have nearly enough. The Germans had a similar problem.

[@stephenkneller6435]

One merely need to look at the cooling issues B-36s suffered from with their six pusher radials, to see some of the issues such designs would have faced had they seen service.

[@mastathrash5609]

Never heard of the Mansyu, prototype or not it's a pretty cool design

[@ronaldbyrne3320]

Fascintating. I wonder if Japan had any help on these from Germany? Thank you for this video. 👍🏻👍🏻

[@thhseeking]

They'd have known about the BMW801 with its fan, and the Ki-61 used a licence-built DB601

[@ronaldbyrne3320]

@@thhseeking thank you. ☺️

[@evertR]

In WW1 there were also pusher planes, probably with radial or rotary engines

[@CaneFu]

It looks to me like the Japanese recognized the superiority of America's P-38 Lightning during World War 2. It's no coincidence that America's top ace all scored his kills while flying the Lightning with its superior nose guns placement. And Japan's top military leader who planned the Pearl Harbor attack was also shot down and killed by a P-38 Lighting.

[@cabanford]

Love the direct P-38 tail copy.

[@indicible4794]

The plane at 1:38 is a Curtiss P-36 Hawk (aka Curtiss H-75), for those wondering. en.wikipedia.org/wiki/Curtiss_P-36_Hawk

[@user-vj7el2wg9b]

Yes, thanks. I was wondering. With RAF markings?

[@builder396]

Yeah, I dont think the engines wouldve been adequately cooled that way. Germany tried much the same thing on the Fw190, with early prototypes having a cowling that left a mere slit between it and the propeller hub, but a fan, much like the one on the Ha-211, would fix it. It didnt. Also, the fan is so similar that honestly I was wondering if you were trying to sell a picture of a BMW801 off as a Japanese engine. In the end the cowling had to be opened up more, if for no other reason than that the pilots legs were being baked. But I also honestly see a very simple fix here. Just cut down the front fuselages width by making it slab-sided around the cockpit, so that around where the slots are you can keep it round and use the gap between the two as a giant air scoop on both sides. With that I could see a chance of it getting cooled properly.

[@SCjunk]

except the at aircraft shown at 0:47 is a rotary not a radial, a rotary works by having its crankshaft stationary and the cylinders fixed to the propellor to act as a flywheel.

[@VersusARCH]

Yup. A Sopwith Camel. The issue early on was cooling - with modest speeds of the early aircraft there was insufficient airflow to cool a (later) conventional radial engine so they solved the problem by having the cylinders rotate with the propeller.

[@onkelmicke9670]

How do you feed the fuel to the rotary cylinders?

[@Puckoon2002]

@@onkelmicke9670 Through the hub.

[@SatumangoTheGreat]

​@@onkelmicke9670the crankshaft is hollow, supplying the engine with a fuel/oil mixture (the oil is for lubrication).

[@giorgiotoso1039]

The Bristol family of Radials (Hercules, Centaur, ...) did not use poppet valves at all, but rather sleeves. They were generally successful, but also rather unique. 😃My best definition of a true radial would require radially mounted cylinders linked to a single crankshaft. BTW, there were a number of experimental "fake" radials made up of several inline blocks of cylinders mounted radially, each with its own crankshaft, geared to a common propeller shaft. These would be mostly water cooled...

[@brookeshenfield7156]

Aloha, going great! Mahalo for your work…

[@FlorinSutu]

6:40 and 10:26 - - The real prototype from the photo shows a push-pull with front and rear propellers, while the nice color artwork, along the whole video, shows pushers-only.

[@EricCoop]

Loving that Streetfighter reference with Blanco. I'm more of a Dhalsim fan. YOGA FLAME!

[@gregedwards1087]

Spark Plugs (plural, many, multiple), all internal combustion engines used for aircraft have at least TWO spark plugs and TWO ignition systems (two magnetos and two sets of plug leads) as a safety net against failure of one system.

[@the_unrepentant_anarchist.]

If we're talking 'unusual Japanese warplanes', how about the Shinden/Shinden Kai? Quite the fascinating little aircraft... 🍄

[@haroldshull6848]

There's another engineering factor for rotary engines which is usually glossed over. The propellor, cylinders, and crankcase spun around the center of the crankshaft; which was bolted to the firewall. The offset of the master rod was stationary. The pistons, attached to the connecting rods rolled in a circle around the offset the up and down motion being the offset of the two assemblies around the crankshaft. The attraction? Minimal vibration. The pistons scribed a circle around the crank offset, the cylinders scribed a circle around the center of the crank effectively double the offset. Vibration was a big concern with everything held together with glue and wood screws. The torque from all that spinning metal was manageable - barely. Great snap rolls, they were tremendous one way - the other way was a slow turn. Use what yea got ...

[@stupitdog9686]

I expect the enemy would know which way you would break if attacked from astern, and would be waiting for it !!?

[@Puckoon2002]

All WW1 engines were rotary, i.e. the crankshaft is bolted to the airframe and the propeller is bolted to the cylinders, so the whole engine spins with the engine. With the later radial engines the cylinders are bolted to the airframe and the propeller is bolted to the crankshaft, so only the propeller and crankshaft spins.

[@twinpiperzed7222]

Not all were radials

[@rej1960]

Not all. The French firm Salmson built water-cooled radial engines with stationary cylinders like WWII radial engines. Anzani also built air-cooled radial engines, up to a 20 cylinder engine good for 200hp in 1913.

[@knoll9812]

That external fan doesn't make sense. Put the fan on the engine so that it sucks air into bay. Also have slots protruding into air stream

[@petter5721]

Looks like the SAAB 21.

[@cabanford]

WWI was mostly "rotary" engines. WWII were radials.

[@speedandstyletony]

Rays? Never heard that term used for the cylinders of a radial engine before and couldn't find anything with google either. It is what they are from a geometry point of view but still not used from what I could tell.

[@brianb-p6586]

Correct - no one uses this terminology for engines. Radial engines have radially-configured cylinders.

[@davidjernigan8161]

The wind god looks like Ed Roth art.

[@obi-ron]

In the third year of fighting the Americans and having come up against P38s, but already beginning to suffer from materials shortages, this looks like the Japanese attempt at keeping up technologically but developing good inline engines would have taken years they didn't have. Nice video 👍

[@kengilmore2563]

Call them by the technical term used by people who have to work on them. Big ole roundie rounds.

[@jebise1126]

0:55 whats that? radials always have odd number of cylinders per row but this one has 6.

[@brianb-p6586]

Four-stroke radials with a single row have an odd number of cylinders so they can have a regular firing interval. multi-row radials don't need that, and there are some four-stroke multi-row radials with an even number of cylinders per row; they need separate camshafts for each bank of cylinders because the common cam rings only work with an odd number of cylinders. But the Anzani at 0:55 does not have 6 cylinders per row - it is a 2-row engine with 3 cylinders per row. The rows are very closely spaced (possible due to large gaps between cylinders with only 3 cylinders in a row) so it looks like a single-row engine unless you look carefully.

[@jebise1126]

@@brianb-p6586 oh you are right. it really is 2 row engine. also can you name any radial with even number of cylinders per row?

[@mickvonbornemann3824]

This aircraft reminds me of a Russian aircraft from about 1940. This aircraft was also a twin boomer with a rear engine in the main fuselage, combined with a pusher prop, together with heavy cannon armament at the front of the main fuselage & tricycle landing gear, but a ramjet contained within each of the 2 boom. So during take off, landing & cruising, only the main engine & prop operated, but in combat the 2 ramjets came in play, giving way over 400mph performance in 1940. However with Operation Barbarossa & the transfer of Russia’s aircraft industry being transferred east of the Urals, Russia cancelled all designs that didn't look like they would be finalised & fully sorted within 6 months. Also by having all the guns in the middle it would have all the benefits of zero deflection gunnery, meaning better accuracy, easier training & much simply sights to boot,

[@rbilleaud]

Re radial engines: Kurt Tank: Hold my beer.

[@HotelPapa100]

"These kinds of engines were incredibly common in the early days of aviation!" Proceeds to show a plane with a rotary engine. Which, technically, is a radial, but doesn't work at all according to the principle just demonstrated.

[@alecblunden8615]

You illustrate the concept of the radial engine by a photo of a rotary engined fighter. A different concept.

[@JustaPilot1]

I'll be that guy. Aircraft engines like the radial pictured have two plugs per cylinder and separate magitoes for each. Two plugs per cylinder, two magnetos.

[@maxasaurus3008]

Radials powered the United States through WW2 in the Sherman tank. That’s why they had such a high profile for a tank.

[@nomad8723]

Makes me wonder if one could make more efficient use of a pusher like this utilizing ducting geometry and/or the venturi effect to recoup some of the cooling air as thrust akin to a high bypass turbofan. I'm sure it would still be less optimal than traditional designs, but it would be a good project for undergrads.

[@MikeBracewell]

Not bad video, but the statement that radials were common in early aviation simply isn't true. Most aero engines were either inline or rotary, as illustrated by the picture of the Sopwith Came you used, which is a wholly inappropriate choice (you can even, just see the engine is spinning). No Camels & very few aircraft of that era were propelled by radial engines - these only began to gain popularity in the 20s. As others have said, rotary engines look the same as radials, when unpowered-up, but operate in a very different way. In a radial, the engine is fixed to the aircraft's firewall with it's crankshaft turning the propellor, just like in an inline engine. With a rotary, the crankshaft is fixed to the firewall & the rest of the engine rotates around it. The propellor is fixed to the engine & so turns with it. Rotary's run cooler & are even simpler than radials as fuel & oil is fed to the cylinders by centrifugal force & so require no gearbox, pumps, etc. The downsides are they generate dreadful gyroscopic torque effects & spray oil & uncombusted fuel everywhere. Another issue is the stress they place on the crankshafts, limiting the power & RPM such an engine can generate.

[@davetomlinson9063]

I would argue that for Japan everything after midway was second half of war as production costs outpaced supply.

[@davidrolfe9571]

Who would ever call the radially arranged cylinders "rays"? Or is this the previously unknown Ray-Deal engine?

[@user-wg8zj7dq1g]

It doesn't matter how cool your interceptors are if you don't have the fuel to deploy them.

[@haveraygunwilltravel]

Most radials had oil cooling along with air cooling.

[@philipfreeman72]

I prefer opposed piston engine . but even jets soon will be obsolete .

[@briandenison2325]

You show a Sopwith Camel, The Sopwith Camel had a rotary engine, not radial.

[@pibbles-a-plenty1105]

Rays? I thought those were called "cylinders." Gee, what I need to learn yet..... 🤔

[@bwjones8903]

Thought I might be the only one never to have heard of cylinders referred to as rays. Guess I’m not crazy.

[@pablolowenstein1371]

There was also the issue of bailing out..into a meat chopper.

[@TomPrickVixen]

Looks like clones of the Saab J21!

[@javierpatag3609]

IHYLS, sir, you *_gotta_* do a video about the De Schelde S.21 (11:32). It looks too weird and wacky not to cover. 😁❤ Even a really short video (or a YT Short) would do!

[@simonolsen9995]

same design concept + jet engine = Vampire

[@kronop8884]

A better comparison would be the SAAB J21 that to my knowledge was the only WWII pusher prop design to enter service, it was later converted to J21R spec using the same jet engine as the Vampire

[@mpojr]

if you had to bail out there is a good chance that the prop would have ground you up,,akin to an ejection seat in a helicopter.

[@briansteffmagnussen9078]

Why do the paint peel of on the Japanese planes? Bad quality og weather salt and age?

[@ukulelemikeleii]

It's because of the type of paint they used and the method for affixing it to the airplane. It was actually an expensive and time-consuming process.

[@Rose_Butterfly98]

18 cylinders? So it had 1 cylinder every 20°? Imagine how smooth that thing ran. Especially since these were 2 strokes.

[@brianb-p6586]

Yes, a cylinder every 40° in one row, and a second staggered to alternate with the front row. But like the vast majority of radials the Mitsubishi engines were four-strokes (with their design copied from Armstrong Siddeley and the Pratt & Whitney models), so only half of the cylinders fire on each revolution, and so there is a firing every 40° of crankshaft rotation. For more detailed information about the Mitsubishi Ha-43 (also known as Ha-211), you might be interested in the Old Machine Press article "Mitsubishi [Ha-43] (A20 / Ha-211 / MK9) Aircraft Engine". I suspect that some of the stills in this video came from the Old Machine Press article, or from the same source as that article.

[@Rose_Butterfly98]

@@brianb-p6586 it's a 4 stroke? Isn't that a nightmare to have to put valves all around? Wonder how the secondary imbalance in a radial engine acts

[@brianb-p6586]

@@Rose_Butterfly98 Yes, almost all radials are 4-strokes. The conventional design uses pushrods run by cam rings that are placed around the crankshaft and gear-driven at half crankshaft speed. The pushrods push rocker arms to operate the overhead valves, just like any overhead valve pushrod engine (which the majority of engines built until the world switched to overhead camshafts). Some engines (such as GM and Ford gasoline truck engines) still use pushrods this way. It's a lot of parts, but in any four-stroke most of the complication is the valvetrain.

[@guypehaim1080]

The WWI aircraft you show has a rotory engine, not a radial engine.

[@advorak8529]

Which shows that the creator @IHYLS has no idea about WW1 aircraft engine technology nor about rotary versus radial engines ... The rotary engine *rotates* around the airframe and the propeller is fixed to the engine block. The radial engine is a normal engine ... just the cylinders are differently arranged from inline to V to VVVVV stuck together to a full circle. The rotary engine allowed much better cooling at the engine speeds common in the days, as the cylinders actively move through air and it could be built light and small. Heck, there is even the Monosoupape design (for rotary engines), which has only one, single, valve per cylinder. The fewer mechanical parts, the less can break. This special design has the drawback that the power can only be reduced by switching off the ignition for a bit (as there is no throttle to reduce the air+fuel input), wasting the fuel and oil normally used; advanced systems would automatically switch off a cylinder once, two or three times before allowing a combustion stroke, on top of the manual blip switch. There are even counterrotation designs, where the crankshaft and cylinder block rotate in opposite ways, either each driving a propeller (1906, Redrup) or only one propeller, connected to the crankshaft (1914, Redrup), albeit that was never got reliable for actual use. Another design (Siemens-Halske Sh.III) ran at effectively 1800 RPM, with cylinders and crankcase running 900 RPM in one direction and the other internal parts at 900 RPM in the other direction, giving a low running speed and a lot of torque. Growing power needs were mostly solved by faster rotation engines --- but the drag of the cylinders through the air raises exponentially, and is not sustainable. Radial engines have static cylinders, still provide the smooth power of rotary engines, are well capable of high RPMs without the drag rotary engines have, do not require a complete-loss oiling system, ... The Parisian Air and Space Museum has a cut model of an engine that shows the difference between rotary and radial by switching between the 2 different methods. Fix the URL in the obvious way. https: //vimeo.com/ 41546699 Radial engines still have the cylinders directly facing the flight wind and at speed will get considerable cooling, and will keep running even with a failed cylinder, no water circulation system to get busted, ...

[@guypehaim1080]

@@advorak8529 Nice essay. I learned a few things. I have a couple of points to make. The crankcase of the rotory engine rotates around the crankshaft, not the airframe. It is true that early rotory engines had no throttle in the normal fashion that's why they used a kind of hit and miss way of reducing power. Later the engines were equipped with a slide valve carburetor similar in design to today's Mikuni models. Another problem with the rotory engines was the amount of torque the spinning engine imparted to the airframe. It was so much so that it killed a few fledgling pilots. With the clockwise rotation, it was easier to turn, bank and roll to the left as opposed to the right.

[@pilotblue6535]

It wasn't just Japanese technology but lack of experienced pilots to fly them

[@luiszuniga2859]

Godzilla -1....

[@robertrawlyss7373]

Looks like a thunderbird

[@dougstubbs9637]

Luke…I am your Pilot…

[@obsidianjane4413]

"Radial engines were simple" But then they became OMG.... "Japan did not have the mfg. capability to produce inline engines" That is not true. They just preferred radials. So their production capacity was centered on them. Choice of engine had no bearing on the success/failure of their pusher designs. They simply started work too late and did not have the resources/time to develop.

[@kevanhubbard9673]

Shintoism is held to be a Pantheistic religion in that there is no distinction between manifest divinity and unmanifest divinity.So we might see their wind god as an aspect of nature rather than something from outside of it.

[@davidjernigan8161]

The Mansyu looks like a Lighting, Mustang, and Curtis's Ascender got together and had a love child.