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It will be interesting to see what the Japanese come up with in place of their heavy fighters Kawasaki Ki-45, Ki-102 and Nakajima J1N. The IJAF thought they had the need of a heavy companion to their lightweight Ki-43, etc., so they'll design something for the heavy fighter, but what engine?
It will be interesting to see what the Japanese come up with in place of their heavy fighters Kawasaki Ki-45, Ki-102 and Nakajima J1N. The IJAF thought they had the need of a heavy companion to their lightweight Ki-43, etc., so they'll design something for the heavy fighter, but what engine?
Tomo is correct on the R-2180 however it may have made for a lousy fighter engine without a lot more development. All but one model used a single speed supercharger and while military power is not listed (for the most part) max continuous power seems to have been around 1000-1150hp at 9,000-7,000ft, please note that a 2 speed R-1830 running on 100 octane had a max continuous rating of 1100hp at 6100ft in low gear and and 1000hp at 12,500ft in high gear. The R-2180 twin Hornet was about 150lbs heavier and about 3 1/2 in larger in diameter. The post war version (1/2 of an R-4360) certainly made more power, it also weighed around 200lbs depending on which models you compare. It may have needed manufacturing techniques pioneered with the R-2800 C.
I didn't mention the IJAF heavy fighters because they were any good. These were their twin engine fighters that we're needing to either replace or entirely delete.Ki-45 was 'heavy' in sense that it used a lot of engine, but not in sense of bringing out a lot of firepower
As an engine for army fighter, the R-2180A will get a turbo to help out.
Is it an unlikely evolutionary leap to get to an engine in service by early 1942 that can support a Japanese single-engine heavy fighter? Something with armour, six or eight guns/cannons, bombs, 400 mph top speed, etc?They don't have a chance, they had no large, high power engine is service or about to be in service at the point in time the Ki-45 was designed.
The post war version (1/2 of an R-4360) certainly made more power, it also weighed around 200lbs depending on which models you compare. It may have needed manufacturing techniques pioneered with the R-2800 C.
The R-2180 was 19% bigger than the R-1830 but ran 92.6% as fast, power is going to be about 10% higher unless something changes.
This is probably why P & W tossed it in the Bin and went for a bigger engine. The R-2180 and the R-2800 use the same bore and stroke.
The R-2800 is basically (ver, very basically) an R-22180 with two extra cylinders per row.
The R-2180 was 19% bigger than the R-1830 but ran 92.6% as fast, power is going to be about 10% higher unless something changes.
This is probably why P & W tossed it in the Bin and went for a bigger engine. The R-2180 and the R-2800 use the same bore and stroke.
The R-2800 is basically (ver, very basically) an R-22180 with two extra cylinders per row.
They don't have a chance, they had no large, high power engine is service or about to be in service at the point in time the Ki-45 was designed. Their big bomber engines only offered a few hundred more HP than their fighter engines and sometimes not even that.
Is it an unlikely evolutionary leap to get to an engine in service by early 1942 that can support a Japanese single-engine heavy fighter? Something with armour, six or eight guns/cannons, bombs, 400 mph top speed, etc?
Can't we just add another bank to the 14 cylinder Mitsubishi Kinsei and Kasei or another nine pot bank to the 18 cylinder Nakajima Homare?
you are applying the retrospectroscope.
What were the available engines or engines in prototype form when the development of the twin engine planes was started.
The work on the Ki-45 was started in 1937, a Mock up was inspected in Dec 1937 and the Army oredred a prototype which first flew in Jan 1939 (not very well, lots of modifications needed) but the question isn't what engines were available in late 1941 but what were available in early 1939 or likely to be available in late 1939 or early 1940.
You can look at many WW II aircraft and say they were not designed well if you compare them to a plane using an engine 12-18 months later in timing.
From Wiki.(my bold)
Kasei was certainly available in 1939, the prototype of G4M flew with it.
From Swampyankee's list
the R-3350 and Centaurus can be taken out as any plane designed for the 1938 versions is years away from production. Wright for example added 2 inches to the length of the crankcase (and crankshaft) on the R-3350 in order to make room for vibration dampers. The engines used in the B-29 were much different than the first handful of 1938/39 engines.
- Merlin
- Vulture
- Exe
- R-2600
- R-3350
- R-2800
- Centaurus
- V-3420
All of the Napier H engines were designed by Major Frank Halford. I believe (open to correction) that he was operating as a consultant and not a direct employee of Napair.
Let's remember that the Man you designed the Napier Lion had jumped ship and joined Rolls Royce around 1930. In house idea men were short supply and even the men who did the grunt work ( stress and vibration) seem to have been a bit thinly stretched.