Most Beautiful Aircraft of WW2?

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I wonder what a twin engined IJN fighter would have looked like. My guess, a mini Ki-96.
They had many twin-engined heavy fighter types.
Most were two-seaters like the KI-45, KI-83, KI-46 (Type 100 Air Defense Fighter) and KI-102.

The KI-96 was actually a single-seat version of the KI-45, BTW.

Then there were some prototypes like the J5N1, which was a single seater, KI-93 (two-seat), KI-38 (two-seat), etc.

There was also the unusual KI-64, which was a single-seat, twin-engine heavy fighter. It was unusual in the fact that both engines were in the fuselage (like a Do335 - sort of), but both engines driving the prop in the nose.
 
Having problems with my phone, so I missed the Navy part.

I did list the J5N1 and as it happened, the Navy was slow to come to the conclusion that they needed to consider land-based fighter types before 1942/43 and the loss of most of their fleet carriers occurred.
 
I'd want an IJN twin carrier fighter to be in-line powered for the least drag, like a DH Sea Hornet. But the IJN lacks the engines, so we're more likely radial powered. The Tigercat was quick enough.
 
Only problem with that is the Japanese were very good with radials and not so hot with inlines.

They never got the Atsuta (Japanese DB) right and a friend of mine who SHOULD know since he flew about 15 Atsutas after the war in Ki-61s, said it was because they missed an oil return line from the nose case. He claims the Atsuta would run for about an hour or so and then the nose case was full of oil and started to overheat while the rest of the engine was low on oil, too. Not too sure of he was right, but the Japanese radials were pretty good as far as reliability ... well, most of them. The Homare was OK when it was built right, but constant bombing made that problematic, to say the least, coupled with low stocks of critical metal raw material.
 
Well, the photos of Atsuta's I see, have the reduction gear case drain hoses. Difficult to argue with a passed-on comment. However, in my opinion the DB 601/605 in many versions may have been a bit weak on scavenge from the front of the cam covers where the oil return drains from the front reduction gear. These engines had problems with oil frothing and late versions introduced a centrifuge oil separator and additional scavenge pumps in the forward end of the cam covers. But, 100,000+ DB 601's and DB 605's worked without these changes, although they would have been better incorporated, and DB wanted too! Overall, DB oil problems are quite complex and even the oil was poor.

Eng
 
The source I heard said it was an oil return line not drilled from the nosecase through to the main crankcase.

The story was that this pilot had formerly been an A & P and, when the Ki-61 had engine trouble in Georgia or Alabama, he removed the engine, disassembled it, and found no oil return line that normally is drilled through the interface between the nosecase and the main crankcase.

I have no way of checking the information since I have no access to a WWII Atsuta engine. It remains a story that I heard but is unsubstantiated, and very likely to remain so. Any Atsuta display is likely owned by a museum or entity who won't like their engine disassembled, inspected, and reassembled by someone who is not a recognized warbird engine expert.

For two and half years I worked at an engine shop that overhauls Allisons and the odd Merlin, but that doesn't qualify me to claim I'm an expert. All it means is I'm more familiar with V-12 aircraft engine internals than someone who has never taken one apart.

So, take it with a grain of salt. But, there is SOME reason why the Atsuta never was developed into a reliable engine when the DB it was derived from was WAS reliable. Many of the stories I have read about Atsuta troubles mention oil issues, so ... the story above is one explanation from someone purportedly both a pilot and a mechanic, who got interested enough to pull a failed engine and look at it. Most US-based WWII Japanese airplanes that ran into issues were just scrapped without further ado.

The Mitsubishi J2M Raiden at the Planes of Fame was rescued by Ed Maloney from a playground where kids were climbing all over it after having mechanical issues while in service here in the U.S.A.. Granted, it never got returned to flying status. But that's more due to no parts for an engine with no U.S. equivalent than to anything else. The airframe is restorable. Not sure the actual engine is without some serious overhaul absent any parts to support same.
 
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Hi Greg,

Well, the DB 601/605 family crankcase, at the front where the reduction gear lives, is open to the main pistons, rods and crankthrows chamber only at the top, above the no1 Main bearing block cap. There is no connection or passage below that. Edit: See post#682.
Scavenge oil from reduction gear pressure lube feed collects in the bottom of the reduction gear case and exits down into two large bore flex pipes that lead one to the front of each cam cover, This is gravity drain. There is a hole in the middle of the front face for the engine cannon blast tube and the rear propshaft bearing but, there is an oil seal to stop oil going into the blast tube and propshaft.
I will put up a few illustrations after supper.

Cheers

Eng

Edit: See post #682 to cover crankcase forward oil drain path
 
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Hi Greg,
Here are a couple of illustrations. The first should be the front face of the crankcase. It is not totally obvious but, there is no passage back apart from, the area above the crank and the hole for the propshaft/blast-tube which has an oilseal. Below the case is the Y-piece and the oil drain pipes to the cam-covers.
The last pic is a dia of the oil circuit, you can see the oil collects in a bit of a bath below the reduction gear before going down the pipes, but this is artistic licence as there is no dam to create the bath.
Of course, the Atsuta may have been different and could have suffered oil circulation problems.
Cheers

Eng

 

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