Did anyone in Japan try/consider using the 18-cylinder Kasei ("Jusei") engine on the J2M Raiden?

[Kilkenny]

The Ki-67 Hiryu got them. Wouldn't it have been prudent for the IJN to put them in the J2M Raiden? This would have allowed for most pilot/fuel tank armor and perhaps a higher speed; and may not have delayed things any more than the J2M was already delayed.

 

[Shinpachi]

Sounds like a what-if for the modern enthusiasts.
"Jusei" makes no sense as Mitsubishi adopted planets' name though I am curious how it is written in Japanese.

 

[Kilkenny]

Sounds like a what-if for the modern enthusiasts.
"Jusei" makes no sense as Mitsubishi adopted planets' name though I am curious how it is written in Japanese.

Goodwin/Starkings says it means "Multiple Star". In any case, it was the MK6/Ha-42 joint engine. In a "what if" scenario, MHI would have had to develop it in 1941 and put it in service by 1943 (in a "J3M") for it to have made any difference. But of course we know that the ultimate fate of the IJN/IJAF and Japan would have been the same, just a year or two later...

(Thank you for responding, Sensei)

 

[Shinpachi]

Looks like not my job.
Thanks.

 

[AerialTorpedoDude69]

"Jusei" might mean 10-star, which could be all nine planets plus the Sun or 十星 (but this is without the "tsu" counter, which is not grammatically correct).

K Kilkenny each variant of the Kasei that was built for the Raiden had to be specially developed with an extension shaft and I don't see a single one that had been developed for the Raiden anywhere. My guess is that the additional four cylinders added enough weight that it made use on the Raiden unfeasible.

 

[tomo pauk]

Raiden with the Ha-42 is sorta Japanese land-based Bearcat?

 

[AerialTorpedoDude69]

Raiden with the Ha-42 is sorta Japanese land-based Bearcat

I didn't realize that was the Ha-42! Check out the Air and Space Museum's surviving model:

Mitsubishi Ha 42 Model 41 Ru (Ha 214 Ru), Radial 18 Engine

Type: Reciprocating, 18 cylinders, 2 rows, radial, air cooledPower rating: 1,715 kW (2,300 hp) at 2,500 rpmDisplacement: 54.1 L (3,300 cu in.)Bore and Stroke: 150 mm (5.91 in.) x 170 mm (6.69 in.)Weight: 1,235 kg (2,723 lb)Outside dual superchargers; Fuel injected; Cooling fan; T

airandspace.si.edu

It clearly has a fuel-injection system, although it's also an Ru (supercharged) variant.

 

[Kilkenny]

"Jusei" might mean 10-star, which could be all nine planets plus the Sun or 十星 (but this is without the "tsu" counter, which is not grammatically correct).

K Kilkenny each variant of the Kasei that was built for the Raiden had to be specially developed with an extension shaft and I don't see a single one that had been developed for the Raiden anywhere. My guess is that the additional four cylinders added enough weight that it made use on the Raiden unfeasible.

Yeah; of course they would have had to add to the length of the plane (or otherwise rebalanced things). But it seems that the extra power would have served a Raiden 2 well, especially if it enabled more protection (more speed was not really needed for bomber interception purposes).

 

[AerialTorpedoDude69]

Yeah; of course they would have had to add to the length of the plane (or otherwise rebalanced things). But it seems that the extra power would have served a Raiden 2 well, especially if it enabled more protection (more speed was not really needed for bomber interception purposes).

I think the weight of the Ha-42 isn't just a little more than the Ha-32, it's a lot more, and it has a larger diameter for whatever reason. From this discussion thread (written by C cherry blossom and S Shortround6 ) we have the following data:

Mitsubishi Kasei.............1850 HP................1340mm...........780kg............42L ( 2567ci ?)
Mitsubishi Ha-104.........1900 HP................1372 mm.........1140 kg.........54.1L (3301 ci)

Which suggests that for 50 more HP than the 32, it weighed 360kg more. NASM's site says that the Ha-42 (Ru subvariant) actually produced 2,300 HP, in which case, I'd also like to know why an interceptor wasn't considered based on it since the Ru version had good high-altitude performance as well as extremely high horsepower.

It could have been that its super heavy weight would have required a completely new airframe. In 1944, there were already aircraft in development with the necessary performance for intercepting B-29s. Bomber development was deprioritized in favor of interceptors so bomber engines may have also been pushed to the wayside.

 

[tomo pauk]

Which suggests that for 50 more HP than the 32, it weighed 360kg more. NASM's site says that the Ha-42 (Ru subvariant) actually produced 2,300 HP, in which case, I'd also like to know why an interceptor wasn't considered based on it since the Ru version had good high-altitude performance as well as extremely high horsepower.

'Ru' = has a turbosupercharger attached to the engine. Japanese production of turboes was minimal.

Mitsubishi Kasei.............1850 HP................1340mm...........780kg............42L ( 2567ci ?)
Mitsubishi Ha-104.........1900 HP................1372 mm.........1140 kg.........54.1L (3301 ci)

Ha 104 (Ha 42 Mod 11 - as used on the Ki-67) weighted under 1000 kg. Kaseis with extension shaft were around 850 kg. All dry weights.

 

[cherry blossom]

Goodwin and Starkings give a weight for the Ha-104 of 1140 kg on page 120. They don't actually say dry weight, so there is some wriggle room. They give the weight for the A18E version (Ha-214) which gave 2,300 hp as 1,235 kg on page 123 and suggest that it was significantly redesigned.