Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: Mirage on February 01, 2011, 04:15:51 AM
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J2M vs Fw 190 A/F Cowl design, just browsing the net and am currious as to how the japanese were sccessful with the J2M's cowl design, did it suffer serious over heating problems? if not, how did then manage to get the cowl so tight but still allow sufficient cooling? because on all pictures, it seems like the J2M's cowl resembles Fw 190V-1's cowl?
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From what I recall, they had the bomber engine in the J2M set pretty far back and used and extend cowling so that they could get a tighter fit around the prop. They used a cooling fan to help pull air in for cooling. That's why shes got that extended snout, even with a radial engine.
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I realise that it is extended, my question was how they cooled it adequately with such a small opening
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I recall reading that the prototype J2M had an even longer cowl, but the main problem it had wasn't overheating, it was the long prop shaft causing vibrations or some such.
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And usually the front cylinders are fine, what ever the arrangement, but its the back cylinders which have trouble getting enough cooling if the engine cooling is a tight fit. I recall that it was a problem in BMW801 for quite long even after they had FW190 up and flying and realized that the engine needs baffling to get fresh air to back cylinders. Of course this is only a problem in twin radials. Also the venting in rear of the engine compartment helped to solve the overheating problem. It also seems that there was more venting in J2M than in FW190 which also relied on engine compartment overpressure to keep oil cooler effective. There was a separate oil cooler under the nose in at least J2M3 onwards, I don't know about the earlier variants.
Nice pic of Mitsubishi Kasei engine arrangement: http://galerie.palba.cz/displayimage.php?pos=-6948
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so they over came the fronts short comings by opening up the back even more, I never thought about this before but I just sort of made my own mental image of how the air behaves once it is in the cowl, that makes sence and thanks for the clarification
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I will add, that seeing those pictures really makes me want to see the J2M added to AH. I'd like to see it in two versions, J2M3 and J2M5.
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I will add, that seeing those pictures really makes me want to see the J2M added to AH. I'd like to see it in two versions, J2M3 and J2M5.
:aok
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Another brick like the A8 and nobody would fly it, except masochists... :uhoh
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The Fw190a8 IRL was more nimble than the rest of the FW A-series .
It had the same wingloading , due to a improved slight larger , lighter wing design, among other things.
With the GM-1 A8 was an equal in speed to its competitors at low-medium-alt.
50% of JG26s Focke-Wulfs where equpped with this booster-system during the fighting in france following the invasion.
In AH we have an overweight A8 with no GM-1.
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I think I am going to go pop a hit of acid and ponder this question of yours on a whole different level. Will return with the results in about 8 hours.
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It had the same wingloading , due to a improved slight larger , lighter wing design, among other things.
The wing area of the Fw190s remained unchanged throughout the A-models and also through the D-series.
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There was a small modification starting with the A-6, but the extent was simply reorganizing the outboard gun bay to accept the larger magazines and guns and internal stuff for the later outboard armaments (MG151/20s and Mk108s). It wasn't larger and it wasn't lighter and it wasn't an improvement (not aerodynamically, I mean).
Also, the 190A8 never had GM-1, and GM-1 will damage an engine if run below 30,000 feet or so. It's an extreme altitude boost only.
You may be thinking of MW50.... :noid
However, not many A8s had this installed. Many used the MW50 tank to store regular fuel. This is where the AUX tank in aces high comes into play. That's why the Dora doesn't have an AUX (it's holding MW50 instead).
The 190A9 may have had MW50 in small numbers, but overall it wasn't big for the Antons.
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Another brick like the A8 and nobody would fly it, except masochists... :uhoh
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I think the J2M could handily outclimb the A8, it with only 70% of the A8's wingloading should be more manueverable as well. It would give up 30-40 mph to the FW in top speed, and I couldn't guess at what its rollrate comparison would be. I think it looks much cooler than the N1K but would be similiar in performance and armament to the George, so maybe its not different enough to warrant inclusion in the game. Still, compared to other Japanese fighters like the Zero or Oscar it's a muscular brute with a powerful punch. I'd like to see it in game someday but then I fly the 39Q fairly often so I think I must be a masochist! :devil
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I would love to see the J2M's in AH in what ever variant we might get.
I still think the J2M didn't quite behave in the dives at 350mph+ like the George. The J2M did have the same number of cannons as the George, but only two of them were the Type 99 Mk2's. To smooth up the airframe they switched the outer cannons back the Type 99 Mk1's. I think the George would be better in the dive and still have better punch. Just those two differences for me would warrant its inclusion in AH, making it different than the George.
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I would love to see the J2M's in AH in what ever variant we might get.
I still think the J2M didn't quite behave in the dives at 350mph+ like the George. The J2M did have the same number of cannons as the George, but only two of them were the Type 99 Mk2's. To smooth up the airframe they switched the outer cannons back the Type 99 Mk1's. I think the George would be better in the dive and still have better punch. Just those two differences for me would warrant its inclusion in AH, making it different than the George.
As I understand it the guns depend on the version we get. J2M3 has mixed guns like you list and was the most common version. If we got the J2M3a or, better yet, J2M5 in addition to the J2M3 we'd also get one with a uniform armament of four Type 99 Model 2s as well.
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Another brick like the A8 and nobody would fly it, except masochists... :uhoh
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Don't go there in this forum Charge. :furious
The Fw190a8 IRL was more nimble than the rest of the FW A-series .
It had the same wingloading , due to a improved slight larger , lighter wing design, among other things.
With the GM-1 A8 was an equal in speed to its competitors at low-medium-alt.
50% of JG26s Focke-Wulfs where equpped with this booster-system during the fighting in france following the invasion.
In AH we have an overweight A8 with no GM-1.
This.
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Krusty is right A-8 is heavy, but GM-1 would be usless in AH as like krusty said, It was an ultra high altitude boost (which even the luftwaffe never really caught on too)
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As I understand it the guns depend on the version we get. J2M3 has mixed guns like you list and was the most common version. If we got the J2M3a or, better yet, J2M5 in addition to the J2M3 we'd also get one with a uniform armament of four Type 99 Model 2s as well.
It would be great if we got the J2M5 as well. Would be very usefull over Japan in 1945 for the FSO and Scenarios.
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There was a small modification starting with the A-6, but the extent was simply reorganizing the outboard gun bay to accept the larger magazines and guns and internal stuff for the later outboard armaments (MG151/20s and Mk108s). It wasn't larger and it wasn't lighter and it wasn't an improvement (not aerodynamically, I mean).
Also, the 190A8 never had GM-1, and GM-1 will damage an engine if run below 30,000 feet or so. It's an extreme altitude boost only.
You may be thinking of MW50.... :noid
However, not many A8s had this installed. Many used the MW50 tank to store regular fuel. This is where the AUX tank in aces high comes into play. That's why the Dora doesn't have an AUX (it's holding MW50 instead).
The 190A9 may have had MW50 in small numbers, but overall it wasn't big for the Antons.
GM1 could be safely used above the engine's critical altitude. MW50 was only tested on an A-4. The power boosting system was extra fuel being injected.
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http://www.wwiiaircraftperformance.org/fw190/fw190a5.html
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It would be great if we got the J2M5 as well. Would be very usefull over Japan in 1945 for the FSO and Scenarios.
J2M is the only plane that if added would cause me to switch from 190's
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There was a small modification starting with the A-6, but the extent was simply reorganizing the outboard gun bay to accept the larger magazines and guns and internal stuff for the later outboard armaments (MG151/20s and Mk108s). It wasn't larger and it wasn't lighter and it wasn't an improvement (not aerodynamically, I mean).
Also, the 190A8 never had GM-1, and GM-1 will damage an engine if run below 30,000 feet or so. It's an extreme altitude boost only.
You may be thinking of MW50.... :noid
However, not many A8s had this installed. Many used the MW50 tank to store regular fuel. This is where the AUX tank in aces high comes into play. That's why the Dora doesn't have an AUX (it's holding MW50 instead).
The 190A9 may have had MW50 in small numbers, but overall it wasn't big for the Antons.
According to JG26 war diary volume 2 p265 at least some squad aircraft was equipped with GKM-1 booster system after summer 1944. In that case that should have been the R4 version of The A8.
"It raised the fighters crititcal altitude from 5500 6300 meters ". "Its performance top speed my as much as 36mph at altitudes over 8000 meters "
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on a side note Charge, that gallery of the Kaisei engine, if you go to the pic on the left, It is an amazing picture of the experimental turbo charger that was equiped to the J2M4
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Indeed, looks almost like something snatched from a P47 or P38. ;)
Maybe it is a copy of an American design? Anybody know?
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Indeed, looks almost like something snatched from a P47 or P38. ;)
Maybe it is a copy of an American design? Anybody know?
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after sifting through lots of internet BS, It looks like the Kasei 23c engine was only a 2 off for both of the J2M4's, they never solved the problems with the turbo (most articles hint towards the tubo themselfs being the problem, so I would doubt they were copies) this is a really neat plane that has always been on the back burner for me over 190's, but after spending some time in other japanese rides, I would love to have it in game, one of my biggest hinderances to reasearching it in real life is the lack of info about it + I have only found 1 book about it, which I cannot locate to buy anywhere
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I hae just found possibly the best source of information and pictures available on the web and maybe in general aswell of the J2M, it is a 17 MB PDF file, and in japanese, but none the less contains some of the most amazing pictures of this plane I have ever seen
http://www.mediafire.com/?wecbp7ywhznuuym (http://www.mediafire.com/?wecbp7ywhznuuym)
here is a teaser picture of what this file contains:
(http://www.mediafire.com/imgbnc.php/9384fa136d28d7e94c65e071f5bc118a3ed4a759427c104433cabd91644482176g.jpg)
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I hae just found possibly the best source of information and pictures available on the web and maybe in general aswell of the J2M, it is a 17 MB PDF file, and in japanese, but none the less contains some of the most amazing pictures of this plane I have ever seen
http://www.mediafire.com/?wecbp7ywhznuuym (http://www.mediafire.com/?wecbp7ywhznuuym)
here is a teaser picture of what this file contains:
(http://www.mediafire.com/imgbnc.php/9384fa136d28d7e94c65e071f5bc118a3ed4a759427c104433cabd91644482176g.jpg)
Thank you. That had a lot of nice photos, the vast majority of which I had never seen before. Wish I could read the Japanese though.
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I know what you mean :( the pictures are great but I cant help wondering what the text contains
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I hae just found possibly the best source of information and pictures available on the web and maybe in general aswell of the J2M, it is a 17 MB PDF file, and in japanese, but none the less contains some of the most amazing pictures of this plane I have ever seen
http://www.mediafire.com/?wecbp7ywhznuuym (http://www.mediafire.com/?wecbp7ywhznuuym)
here is a teaser picture of what this file contains:
(http://www.mediafire.com/imgbnc.php/9384fa136d28d7e94c65e071f5bc118a3ed4a759427c104433cabd91644482176g.jpg)
Thanks man, good pics :aok
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Another good book regarding J2M .
http://www.wuala.com/-aper-/AH/Mitsubishi_J2M%20Fighter.pdf (http://www.wuala.com/-aper-/AH/Mitsubishi_J2M%20Fighter.pdf)
Might help HTC to model this plane ;)
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It is bigger than I thought it was. Until I'd looked through those two PDFs I'd never seen it with people standing next to it or on it.
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Indeed, looks almost like something snatched from a P47 or P38. ;)
Maybe it is a copy of an American design? Anybody know?
There were two different turbos tested in the J2M4 prototypes. The first prototype had Mitsubishi's own turbo and the second had a turbo made by the 21st Aircraft Arsenal of the Navy. So I'm quite sure they were in house designs. I think that, because of the quite straight forward working principle of a turbo, all aircraft turbos of the era tend to look very similar.
Interestingly enough, the same source states that J2M5 had a three-stage supercharger. Surely they meant to say three-speed supercharger? :headscratch:
(source: Mushroom publication's Raiden-book)
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No stage would be correct, I will explaine later as I just woke up and dont have the brain power to talk complex right now haha, and thats for the File!
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Thanks for this Aper, I doubt many western people have ever seen a cutaway of a J2M before (if you cant read the labels in this SS, DL the PDF aper posted, it has GREAT technical drawings)
(http://www.mediafire.com/imgbnc.php/35315085ef28a5f499ef0bb58f731c050a3065f4fcf5f45d4ddcc9abf90543d46g.jpg)
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"Interestingly enough, the same source states that J2M5 had a three-stage supercharger. Surely they meant to say three-speed supercharger?"
I'd say so since it is addition of stages that grows weight, more speed settings are easier to make, although the optimal speed of the impeller is so restricted that two speed setting pretty much covers what a single stage is capable of. A little more optimization is possible by using a variable speed unit as in 109 (or Szylowsky/Planiol etc.). IIRC Ta152s have two stage/three speed units and they were quite heavy.
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Need the J2M5 very much now.
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Lol indeed, this is its time to shine
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Jack would pwn