N1K2, ver 0.45's Ultimate Vulch Machine ?

[Vermillion]

Last couple of nights I have flown, have been atypical of my AH career. Instead of the usual Hi-Alt meeting engagements, its been more of one side having air superiority over the enemy base, while they try to sortie plane after plane in a suicidal low level defense.

As can be expected my typical plane of choice, the de-fanged P-51 (still a great plane IMO), just didn't feel right for the situation, so I started to shop around the planeset for these Vulch missions.

Tried out the Fw190, but I just couldnt' get it too work in the vertical. I could get kills, but I always ended up dying to the Spitfire/Veltro defenses, and I still like to fly to live.

So looking for firepower, and manueverability in the vertical, I jumped back into my old ride the N1K2 Shinden.

WoW !!  

Either Pyro has made some changes to this planes FM (come on Pyro you can tell us, we're your buds right? hehehe). Or all of a sudden, I have "become one with the Force" when I am flying old George.

Here is my impression, even though it doesn't make alot of sense given what little I know of flight mechanics.

It doesn't seem any faster (or very little), but the plane seems to climb better, accelerate better, and work the vertical much better.

Basically, without a stream of much higher Pony's/Corsair's coming in, it is virtually untouchable in a field supression situation.

You can go in at about 8k-10k, dive into the fight, nail a much lower defender with those great cannons in a single pass, then go vertical and then climb right back up to near your initial altitude.  If you get too low after a fight, just seperate a little and use its climbrate to get back to a "safe" altitude.

Only times I died (twice), was when I got stupid and greedy. I would miss the first guns pass (3% gunnery will do that too you), and then try to turn with the defenders.

Anyone else noticed a difference with this plane or is it just me??

Might go back and redo my original climb/max speed tests to see for sure.

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Vermillion
WB's: (verm--), **MOL**, Men of Leisure,
"Real men fly Radials, Nancy Boys fly Spitfires "

[juzz]

6'55" to 20k, that's 40 seconds faster than last time I checked. Still slow like it's always been before 0.45.

So Vermillion, by your own admission your plane of choice is a Spitfire (inline)engined, wussy Runstang? For shame! You are not a real man at all!    

[This message has been edited by juzz (edited 01-11-2000).]

[Vermillion]

Yep I turned to the dark side Juzz, just another wussy Nancy Boy Runstang pilot now  .

Give me a La-7 or the F4U-4, and I will consider going back to the Light side permanently.

Hey, and give me a little credit  , I did just admitt to flying the N1K2 more in the past two days, than in the past 3 or 4 revisions.

I'm trying.... hehhehehehehe

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Vermillion
WB's: (verm--), **MOL**, Men of Leisure,
"Real men fly Radials, Nancy Boys fly Spitfires "

[Dingy]

<in deep resonant voice>

Verm....

Resistance is futile.  You are destined to fly the Stang.  You and the stang are one....

-Ding

PS...I've tried resisting...I just find the pull too strong!  

[fats]

The P-51 Mustang and its pilots are one, they are a match made in heaven. Formed to be one entity never to be separated. And how could you? There's nothing you could separate after the Mustangs detonate time after time in front of my Fw 190 and its mighty cannons.


//fats

[Ghosth]

Found this entry in Combat Aircraft of WWII,

"N1K2-J Shiden KAI "George 21"
Type Intercepter Fighter
Eng 1 1,990 hp Nakajima Nk9h Homare 21
Max speed at 18,375 feet 369 mph
Cruiseing speed 230
Max range 1,293
7 min 22 sec to 19,685 feet (6km)
wingspan 39' 4", Lenght 30' 8", Height 13'
252.95 sq feet wing area,
4 20mm type 99 Model 2 Cannon in wings
bomb load 1,102 pounds (500 Kg)

Remarks,  Ultimate in Nik series development,
Nik2-j was basicly a much modified but simplified redesign of Shiden Predecessor."

Like you the Niki has been feeling very good to me since the last revisions. Unfortunatly I've been down with a flu bug & unable to take advantage of it.  Stay high, & watch your ammo use & you can live a long time.

Rock on niki's  


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Maj Ghosth
XO 332nd Flying Mongrels

[wells]

More on the Homare engine...

It was an 18 cylinder version of the 'Sakae' engine (950 hp @ 2600 rpm), with the same cylinders, just an increased capacity and able to turn a higher rpm (3000) due to better construction materials and design.  So displacement was in the area of 2000 c.i.  compared to 1700 ci for the 'Sakae' with a compression ratio of 7:1.

Note that the BMW801D displaces about 2500 c.i with a compression of 7.22:1 and it put out 1700 hp.  The R-2800 put out 2000 hp with a displacement of 2800 ci and a compression ratio of 6.7:1.  

Rough figuring of displacements and RPM's puts the Homare's power rating somewhere in the 1300-1600 hp range, which is significantly lower than the commonly printed 1900-2000 hp figure.  It may have produced the latter figures with water injection, but power at altitude (20k) would be in the range of 1100-1400 hp, again, much lower than the 1600-1700 hp figure that is generally quoted for the engine.  

It just doesn't make any sense that the Homare would be that powerful.  Perhaps the U.S. was under the impression that an 18 cylinder engine under developement in Japan would be a copy of the R-2800 as found in the Hellcats and Corsairs.  They then based performance estimates on that assumption (see Vermillion's AW charts).  

[Vermillion]

Some more info on the Homare 21

From "Japanese Aircraft of the Pacific War", by Francillon

One Nakajima NK9H Homare 21 eighteen cyclinder air-cooled radial rated at:
1,990 hp at takeoff
1,825 hp at 1,750m (5,740 ft)
1,625 hp at 6,100m (20,015 ft)


From: "World Encyclopedia of Aero Engines", by Bill Gunston.  (Book isn't worth its high cost btw, pass on it)

Its very thin on the Japanese engines, but here is what it has

Nakajima Sakae NK1 - A6M's Powerplant
(including Ha-25, Ha-102, Ha-105, Ha-115)
9 cylinder single row radial
950hp - 1,230 hp

Nakajima Homare NK9 - N1K2 and Ki-84 Powerplant
18 cylinder double row radial
NK9/Ha-45, NK11/Ha-44, and Ha-145 (all with Sakae size 130 x 150mm cylinders, giving 32 liters (1953 cu inch's))
producing 1,800 hp - 2,400 hp
Ha-217/Ha-46 of 3,000hp

There was also the 4 row, 9 cyclinder version of the Homare the Ha-505 that was rated at 5,000hp.

Not sure where they are getting it from Wells, but given the progression of the engines, it looks like a straight linear progression from the late model 9 cyclinder Sakae (1230hp) up to the 18 cyclinder Homare (1800-2400). So the Homare fits the relationship with the Sakae.

Also which R-2800 are you comparing it too? The R-2800 started the war with 2,000hp, but by wars end, in the "C" series, was producing ratings of 2,800 hp. And didn't the same engine produce even higher ratings in the "Korean" vintage F4U-5's and later?

That gives the later 2800's a 1:1 cu-inch/hp ratio, very similar to the Homare's 1.01:1 cu-inch:hp

How big was the R-4360 ? This book lists it as having 3,000-3,500 hp by VJ Day, and shortly thereafter exceeded 4,000hp with a VDT (variable discharge turbine), but it was canceled before full scale production.

Admittedly, this may have also been the source of the legendary Homare engine problems. The engine was just wound up too tight for the remaining industrial capacity of Japan at that time.

Not sure Wells, I admitt to my ignorance, and have grabbed this stuff from a book. So I am not arguing with you but just offering additional data, but are you sure??

That 1,990-2000 number is awful consistent in every reference I have ever seen for that particular variant installed in the N1K2.

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Vermillion
WB's: (verm--), **MOL**, Men of Leisure,
"Real men fly Radials, Nancy Boys fly Spitfires "

[wells]

I don't believe those figures for the Homare are MIL power ratings.  I could believe them if they were acheived with water injection.

This makes more sense, given the displacement of the engine...

1600 hp MIL / 2000 hp with water at sea level
1300 hp MIL / 1625 hp with water at 20k

I haven't done any flight testing in 0.45 except for a small climb test, but I'll see what I can get for speeds with WEP on.  I would expect to get close to 350 down low and 400 up high! (325 and 370 at MIL settings)

[kjb]

Wells,  There is a lot more than C.I.D. and RPMs, to determine horsepower.  

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KJB
aka kjb  

[wells]

You're right, I don't know what the mean pressure is, but it must be some rediculous value to obtain that kind of power!  I'll post some figures soon....

[wells]

I stand corrected...

The power goes up with the number of cylinders squared, assuming same cylinder dimensions and directly with RPM, so, comparing to the Sakae (14 cylinder 2 row)

(18/14)^2 * (3000/2600) * 950 hp = 1812 hp

Anyone got any anecdotes or any data on what kind of manifold pressure was used on these engines?

[kjb]

Wells, correct me if i'm wrong, but there are other things such as cam, and cam timing, the ignition and the way it is set up, Octane and quality of fuel, exhaust restriction or lack of it. just to name a few of the factors used to determine horsepower.  I don't believe you cn look at cubic inches and decide horse power. You can get a very rough idea of it butt that is about all.

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KJB
aka kjb  

[wells]

I can determine what the theoretical maximum output of an engine could be.  What it actually produces depends on all those things you mentioned, and by comparing both sets of numbers, I should be able to come up with some efficiencies.  If the Homare works out to more than 100% efficiency, then there's a problem!    For the most part, the engines are in the 65-75% efficiency range.

The R-2800 is actually a really low efficiency powerplant in comparison to some others like the DB605, BMW801, Allison, Merlin... That's probably the reason why it was such a robust and reliable powerplant!  It was overbuilt for the power it puts out!