Recent content by z42

Thank you. Exactly what I was looking for! So by looking at those specifications, it looks relatively similar to modern road diesel, e.g. the European spec EN 590 - Wikipedia (of course limits for sulphur and other unwanted stuff is much lower in contemporary specs). Viscosity for the Jumo fuel...

I've been trying to understand what kind of fuel was used for the aviation diesel engines in the interwar-WWII era, primarily the Ju 205, but if you have information for other aviation diesel engines feel free to contribute. On the internet one can find secondary(?) sources (Junkers Jumo 205 C4...

As for aero engines, did the Soviets ever introduce fuel injection (single point good enough..?) or the pressure carburetor during WWII? Seems they persisted with trying to make float carburetors work for quite a long time. Of course, not a uniquely Soviet failing.. Also a lot of blame can...

When looking at improving Soviet programs, starting with the wildly successful F-34 / zis-3 / etc. sounds strange. And same for the follow up 85 mm zis-s-53 that was used on the t-34/85. They're not winning any MV competitions, but so what? The 76.2x385 was a good compromise between barrel life...

For aircraft autocannons there might be a case to be made for a relatively short and stubby shell giving decent enough MV with a more or less straight walled cartridge? Not as efficient ballistically as a thinner and longer shell of the same weight, but at realistic shooting ranges might not...

Here's an article that made the rounds recently about why jet engines are expensive. https://www.construction-physics.com/p/why-its-so-hard-to-build-a-jet-engine The author is not an authoritative source on jet engines, but still, it's a decent enough overview. In particular it has some nice...

My point was that the 801D would also suffer from minute amounts of fuel getting past the rings into the crankcase. But since the temperature there was higher than in the 601N that fuel did evaporate (and eventually get out through the crankcase ventilation system) rather than mixing with the...

AFAIU the problem wasn't that the 601N couldn't efficiently combust C3 per se, but rather that minute amounts of fuel found their way past the rings into the crankcase (as happens with all engines to some extent), and because of the high boiling point it didn't evaporate away, and over some time...

IIRC in Calum's book it was mentioned that they ran out of capacity in the original injection pump, and rather than design a new pump with bigger capacity they just added a 15th pump to inject fuel into the supercharger inlet.

I'm not sure such a halfway position is that useful. You either have a battlefleet that has some chance of beating the enemy battlefleet, or you don't. If you don't, use your money for something else than building a fleet that will certainly be roflstomped by the enemy fleet.

Even if we ignore the treaties, to which Japan was still a signatory when these decisions would have to be made(?), as mentioned before ~1942 nobody was really sure that carriers were the new kingmakers of naval warfare. If you were in charge of naval strategy and procurement before that and you...

If we're happy with 25 kn carriers, I'd like to (re)toot my horn and propose carriers powered by low speed diesel engines! ;) https://ww2aircraft.net/forum/threads/japanese-logistics-purchase-programs-and-war-booty-reality-and-alternatives-1936-44.64955/post-2018241

Yes, as I mentioned back in the age of the dinosaurs on page 1 of the thread! https://ww2aircraft.net/forum/threads/japanese-logistics-purchase-programs-and-war-booty-reality-and-alternatives-1936-44.64955/post-2012013

Slightly (un)related to flying wings, I stumbled upon an interesting NASA paper about spanload distributions, including a flying wing experiment to prove those ideas. Based on a for some reason largely forgotten paper by Prandtl in 1933...

Keeping on the topic of Japanese engines, what about diesel engines for ships? In particular, low speed two stroke ones, having several advantages (which is why they have dominated oceanic shipping post war) : Ability to use the same cheap bunker fuel that steamships use. No need for an...