Best Japanese fighter

[razor1uk]

Ki-116, the Tsurugi? wasn't a lightweight fighter but a cheapest in cost and materials A/C to be used to carry out a suicide attack with a plan-form similar to the Ki44/84

 

[Civettone]

No mate, you are talking about the Ki-115 Tsurugi or Tōka.


Kris

 

[Ivan1GFP]

They tested a Ki-84 with a Ha-112 for conversion into the derived Ki-116, a lightweight Ki-84. There is no reason to assume that this was because the Homare was unsatisfactory. You said yourself that the Homare was working okay for the Shiden. In fact, that is not true either. The N1K2-J also had problems with the Homare. Of course the Kı-84s and Shidens still lost against American planes, the general level of the American pilots was far superior. Even if you read Japanese accounts on this or that plane, you have to take into consideration, that pilots have a limited view on things surrounding them. They may find their plane inferior or superior to the enemy, but the actual results will not always prove them right. A lot of it has to do with mentality and moral, they tend to cloud their judgment.

Kris

I believe I was correct in stating that the Ha-112 typically made more power in the field than the Ha-45 would. I don't remember trhe source, but the number I have seen was around 1300 HP for a Ha-45 which is nominally a 1900-2000 HP engine. The Homare simply could not reliably deliver the performance it was designed for.

Other than that, your disagreement with my post is strange because you are stating almost exactly what I was stating.

I never stated that the Shiden-KAI didn't have engine issues. I just said that it didn't have the same record of problems that the Hayate did. I have no evidence for this next statement but here goes anyway: I believe that a lot of the difference in mechanical reliability was because of where the units operating this aircraft were located in the supply chain. The 343 Kokutai was based on the home islands as opposed to China, Burma, New Guinea, etc.

The book Genda's Blade seems to show that 343 pilots thought they were generally doing pretty well. They thought they were shooting down a lot more US aircraft than they were. The US pilots thought the 343 was doing well also because their tactics and coordination was good. The 1 to 3 kill to loss ratio is MY OWN count from tallying up each side's losses for the recorded encounters. Both sides over-claimed as usual. What was rather pitiful was the deaths of some of the best Japanese pilots due to mechanical failure or circumstance (Kanno, Muto, Sugita).

Regards.
- Ivan.

 

[CORSNING]

And there you go. Nice summation again Ivan. The example of "where" a certain A/C was stationed, "what" A/C it fought, "who"(quality of pilots) was flying the A/C and "how" it was implemented had everything to do with how well it did in combat (its win/loss record). What I'm trying to say is, just because A/C No.1 had a better win/loss record than A/C No.2 does not always meanA/C No.1 was the superior fighter aircraft/fighting machine.

Jeff

 

[GregP]

Talked with Steve Hinton and Ed Maloney today about the Ki-84 we used to have. He said our example was barely flyable and had a very slightly bent prop and they could not get rid of the vibration ... and the gear up locks were nonfunctional. So, although it was quite pleasant to fly, they never got into the higher-performance part of its envelope. At the time, there was simply no demand for it on the airshow circuit and they had NO spare parts so, when the offer came in from Japan, they jumped at it.

The only people who flew it were Don Lycans and Bud Mahurin.

 

[cherry blossom]

I am coming to the view that the post-war American trial performance of the Ki-84 giving a maximum speed of 427 mph is misleading. My reasoning starts from the engine data given at q‹ó‹@ƒGƒ"ƒWƒ"ˆê——E"ú–{ŒR, which gives powers:

Ha-45 11 – Take off 1800/2900 – Military 1650/2000/2900 and 1460/5700/2900
Ha-45 22 – Take off 2000/3000 – Military 1890/1800/3000 and 1750/6450/3000

It also gives for the Mitsubishi's M9K

Ha 43-11 – Take off 2200/2900 – Military 2070/1000/2800 and 1930/5000/2800

Now the Navy's A7M1 Reppu was powered by a Nakajima Homare 22 and is quoted as only having a maximum speed of 310 Knots at 6,190 m (357 mph). The A7M2 was powered by the M9K and had a speed of 339 kt at 6,600 m (390 mph). If we take those speeds and cube them, we can guess the ratio of the horsepower as around 1.303 assuming the weight, drag and propeller efficiency is the same. In fact the M9K was heavier (980 kg vs. 830 kg.) and wider (1230 mm vs. 1180 mm) than the Homare and propellers get less efficient at higher speed. Thus the 1.3 ratio is too low. However, dividing the 1930 hp of the M9K by 1.303 gives 1480 hp. Thus we can be fairly sure that a Homare 22 as supplied to Mitsubishi in Japan gave less than 1480 hp at around 5000 m.

Now it is unlikely that Nakajima was simply telling lies about the performance of the Homare 22. A prototype engine would almost certainly give 1750 hp at 6450m at 3000 rpm. However, the production engines could not match this. Rinkol http://www.ww2aircraft.net/forum/aviation/kawanishi-n1k1-j-kasei-37359.html#post1023836 suggests "The early Homare engines suffered from production quality control problems affecting the intake passages" and that is the best explanation that I have found. Thus the only Homare 22 engines that Nakajima could supply to Mitsubishi had much worse performance than Nakajima prototypes.

Now if we go to the post-war American tests, everything makes sense if they managed to get the quoted performance out of the Ha-45. It is possible that the test aircraft actually had a hand made prototype engine from Nakajima. Alternatively, it is possible that the highly skilled American technicians had a translated manual quoting the expected power, realised that their engine was underperforming and set to work with their well equipped machine shop to remake any defective parts until they brought their engine up to its quoted performance.

The point is that most Homares in either the Ki-84 or the Shidens did not give their quoted performance and that the high speeds quoted could only be achieved with specially manufactured engines.

ps. On reflection, another possibility is that Nakajima actually solved the manufacturing problem very late in the war so that some Ha-45 engines were mass produced in 1945 with the theoretical performance and that one of those went to America for the Ki-84 test.

 

[Civettone]

My guess is that low quality control does not automatically mean less performance, only bigger chance of less performance. As such, I think some Homares delivered the expected performance, others did not. One can debate about the ratio.


Kris

 

[Rogi]

May we factor in captured aircraft that the Japanese used? Or just home grown Japanese aircraft?

Ki-61 if homegrown,

I will wait to see if captured is included

 

[fastmongrel]

My guess is that low quality control does not automatically mean less performance, only bigger chance of less performance. As such, I think some Homares delivered the expected performance, others did not. One can debate about the ratio.


Kris

Quality control gives you the chance of repeating a good engine again and again. Poor quality control can sometimes produce a cracker of a an engine but with no quality control you will never know how you did it, thus no chance of repeating. I used to work for my Aunt and Uncle who owned a British Leyland dealership my cousin and I used to pre delivery inspections and some of the engines were great they started first turn and ticked over smoothly, others from the same batch virtually needed a crankcase up rebuild. British Leyland QC was non existent so they didnt realise that the engine casting moulds were worn and tolerances had gone, plus things like crankcase bearing boring machines were old and worn so some cranks would spin with a finger others would only turn with the assistance of a scaffolding pole. Some people wonder why BL dissapeared others wonder how it lasted so long.

 

[GregP]

Poor surface quality in an intake passage will rob some power, but not much. Poor quality exahust passages will not affect power much if any. It certainly would in a normally aspirated engine, but all these engines were supercharged. Boosted engines are completely different from normally asiprated engines as far as flow goes. Of much more concern would be the main bearing clearances.

Tight clearances will overheat at higher rpm and cause premature failure and loose clearances will not allow the engine to develop full oil pressure and will limit manifold pressure unless you want engine failure. So the pilot would be able to pull only so much power before the oil pressure gets to the limit. Any more power would be a personal gamble.

One place where quality would really affect performance would be if the props were of poor quality finish.

Naturally, the airframe fit and finish is high on the list, too. Leaky gaps are very draggy. You want to prevent air from entering anywhere it is not supposed to enter.

 

[CORSNING]

I really miss the Triumph Spitfire. In my youth I was 6' 4 1/2" and a Spitfire fit like a tailor made glove. It would not win any drag races but who cared. It was pure fun. Now that was definitely one of the best cars to come out of the UK in the 60's/70's.

And I don't care who you are, Jeff.

 

[fastmongrel]

I really miss the Triumph Spitfire. In my youth I was 6' 4 1/2" and a Spitfire fit like a tailor made glove. It would not win any drag races but who cared. It was pure fun. Now that was definitely one of the best cars to come out of the UK in the 60's/70's.

And I don't care who you are, Jeff.

I like the Triumph Spitfires as well. I briefly had a MkI GT6 which looked beautiful, sounded beautiful but if you had to lift in a fast corner the Swing Axle and torque reaction from the drive shaft would make you go backwards through a hedge and end up in a field. Luckily the farmer towed it out of the muddy field before before it sank up to the door cills.

 

[GregP]

Hye Corsining,

I REALLY liked the Triumph GT-6. It was like a roller skate with a lot of power. That 6-cylinder was a real kick when you pushed it hard .... unutil you had to fix it, that is. Also loved the Austin-Healy 3000. Another kick in the panrts when stepping on the go-fast pedal.

Both are sort of like the difference between a Van's RV-4 and a Harmon Rocket. The RV-4 is sweet but the Harmon Rocket is just unbelievable and accelerates when climbing at a 45° angle.

Maybe back to Japanese fighters, like the Toyota 2000GT featured in an early James Bond film, You Only Live Twice. Anyway, back to subject ...

I think the top 3 - 4 were too close to call and "the best", like their European and American cousins, probably depended on the mission and the pilot more than the plane.

 

[cherry blossom]

I am not sure that Nakajima Homare engines were like British Leyland cars. My mother bought a Triumph Acclaim in 1982 and parked it soon after buying it only to discover that the gearbox had fallen out onto the ground under the car once it was no longer held in place by the transmission. However, not all British Leyland cars had such problems and my mother was not testing her Acclaim before buying several thousand. Had she been an important customer, someone may have checked the bolts which should have held the gearbox in place.

By contrast, Nakajima apparently couldn't find a good Homare 22 for the Reppu in 1944 when a major contract might have depended on finding one. We could imagine that they said "any old rubbish is good enough for Mitsubishi" but they must have known that Mitsubishi would use poor performance to argue for the use of the M9K (Ha 43).

It is also clear that the airframe and propeller could not account for the A7M2 going much faster and climbing much quicker than the A7M1. Mitsubishi calculated that their Homare was only giving 1300 hp when the spec said it should be giving 1750 hp.

 

[Milosh]

I to had a Triumph GT6+. It would go like stink (2l. and 2 speed overdrive). Never had a problem like you Fastmongrel in cornering. Didn't like the rain tho (water entered through the hood grills) and the carbs had to have oil added every so often. Eventually pulled the rear radius rods out of the floor they were attached to.

 

[Shortround6]

I had the big brother, A TR-250 (TR-5 with carbs instead of fuel injection).


Curse you, George Lucas.

 

[fastmongrel]

I to had a Triumph GT6+. It would go like stink (2l. and 2 speed overdrive). Never had a problem like you Fastmongrel in cornering. Didn't like the rain tho (water entered through the hood grills) and the carbs had to have oil added every so often. Eventually pulled the rear radius rods out of the floor they were attached to.

They cured the handling problems in the Mk2 GT6 Spitfires by fitting rubber dampers on the drive shafts and fitting a revised wishbone rear suspension which turned a lump into a Lotus beater. Modern radials and modern dampers keep the GT6 Mk1s on the road but you still better know a panel beater if you have to lift off and brake at speed in a bend. If you go to a Triumph owners meet you will soon find someone who put there GT6 Mk1 or Vitesse Mk1 through a hedge

The oil in the carb was a damper to stop the needle bouncing up and down and causing erratic running.

 

[fastmongrel]

Curse you, George Lucas.

He wasnt known as "The Prince of Darkness" for nothing

 

[Milosh]

The oil in the carb was a damper to stop the needle bouncing up and down and causing erratic running.

I know what the oil was for.

Rubber dampers. You mean the rubber universal joints.

 

[fastmongrel]

Yes the drive shaft do-nuts they are called Rotaflex or something. They act as CV joints and driveshaft dampers, basically a metallastic engine mount modified with a big hammer