A new book in my library. (14 Viewers)

[SaparotRob]

I did not know all the Japanese even spoke French!

The things one learns here.

 

[MIflyer]

The things one learns here.

Interestingly enough some authorities have said that the Japanese radial engines were based on French designs and the Soviet in-line engines were based on French designs. With vastly superior American radials and British/American in-lines you have to wonder why that would be. Was availability of French engines better internationally?

 

[buffnut453]

Interestingly enough some authorities have said that the Japanese radial engines were based on French designs and the Soviet in-line engines were based on French designs. With vastly superior American radials and British/American in-lines you have to wonder why that would be. Was availability of French engines better internationally?

I'd be interested to learn what sources make this claim, plus their evidence for it. I can't see any common dimensions between contemporaneous French engines and the Sakai engine.

 

[Donivanp]

I don't know from nothing, but the French Gnome engines were used in several German aircraft such as the HS 129. That being said after the French capitulation it may be some of the Axis cross pollination going on. Again I repeat, I don't know nothing from nothing!

 

[cherry blossom]

If you look at the Sakai's big brother, the Ha-5 or Ha-41 or Ha-109, you might see the same bore as a 14N but a slightly shorter stroke. However, they may both be parallel developments from the Bristol Jupiter.

 

[MIflyer]

I'd be interested to learn what sources make this claim, plus their evidence for it. I can't see any common dimensions between contemporaneous French engines and the Sakai engine.

I believe that book "A History of Aircraft Piston Engines" by H. Smith makes that claim. It's a good book, quite comprehensive, although not everyone agrees with everything in it.

We know that the Soviets copied the R-1820 and the Germans copied some P&W engines, but as for most of the Soviet and Japanese engines I guess we don't really know.

 

[Shortround6]

We know that the Soviets copied the R-1820 and the Germans copied some P&W engines, but as for most of the Soviet and Japanese engines I guess we don't really know.

Germans licensed the P&W Hornet. Follow up technical transfer was ?
Soviets licensed the Bristol Jupiter, H-S 12Y, Wright R-1820. Tech support/updated lasted only a few years (late 30s at best).
Japanese licensed some engines in the later 20s or very earl 30s.
Wright was several generations past the engines sold/licensed to the Soviets in the early 30s. The engines sold/licensed to the Soviets were the F series of about 700hp.
Later Soviet engines were increasingly their own. Granted commercial Wright engines were available for copy but reverse engineering is hard.
And just because you have an engine doesn't mean you can copy it. You need the foundry capacity and machining capacity to make the parts.

 

[Donivanp]

 

[special ed]

Germans licensed the P&W Hornet. Follow up technical transfer was ?
Soviets licensed the Bristol Jupiter, H-S 12Y, Wright R-1820. Tech support/updated lasted only a few years (late 30s at best).
Japanese licensed some engines in the later 20s or very earl 30s.
Wright was several generations past the engines sold/licensed to the Soviets in the early 30s. The engines sold/licensed to the Soviets were the F series of about 700hp.
Later Soviet engines were increasingly their own. Granted commercial Wright engines were available for copy but reverse engineering is hard.
And just because you have an engine doesn't mean you can copy it. You need the foundry capacity and machining capacity to make the parts.

You mean, like the B-29 and her engines?

 

[MiTasol]

I believe that book "A History of Aircraft Piston Engines" by H. Smith makes that claim. It's a good book, quite comprehensive, although not everyone agrees with everything in it.

We know that the Soviets copied the R-1820 and the Germans copied some P&W engines, but as for most of the Soviet and Japanese engines I guess we don't really know.

The Germans built some US engines under licence and then improved them.

 

[MIflyer]

You mean, like the B-29 and her engines?

Actually the Soviets did not use the R-3350 in their TU-4 but instead another engine of their own design.

 

[Shortround6]

Actually the Soviets did not use the R-3350 in their TU-4 but instead another engine of their own design.

Kinda, sorta, maybe?
Wright took the cylinders off the R-1820 and cut 14.3mm off the bottom (actually they did that to make cylinders for the R-2600 and then used 9 cylinders in each row instead of 7 cylinders in each row.
Soviets of the ASh-73 took the cylinders from the ASh-60 series engines (R-1820) and cut just 4,5 mm off the bottom. Soviets had tried to make a 14 cylinder engine using full length cylinders but that didn't get far. Soviets also tried to make 3 different 18 cylinder engines using full length ASh-60 series/R-1820 cylinders but none of them worked well enough to go into production.
No idea of how much of Wright cylinders were left when the Soviets got to the ASh-73 or how much they learned about crankshaft and connecting rods from the captured R-3350 engines.