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leiker06
02-20-2007, 04:48 PM
what i want to know is wonder why the 50 cal in PF is weak? i mean the US used insindiary bullets. i dont know if they used armor piercing bullets. but none the less i think that the american fighters are seriously handicapped. i mean basically it's like 6 50's are equal to one 20mm cannon. i dont get it. can somebody please shine some light on this. also i was just wondering if the p-40 in the game (E and M's) used a truss type of construction, because it seems like they skin is just weak like butter. i nicknamed the thing butter wings for god sake. well just wondering what you guys know.

berg417448
02-20-2007, 04:51 PM
You might try doing a forum search for other threads. This subject has been discussed many times before.

Choctaw111
02-20-2007, 04:53 PM
I will say this quickly here. If you know how to use them they are deadly.

MEGILE
02-20-2007, 04:55 PM
http://forums.ubi.com/images/smilies/sleepzzz.gif

VW-IceFire
02-20-2007, 04:55 PM
You might want to do a search for topics relating to the .50cal. Its a hot button issue.

Most people who try and use the .50cal for the first few times have completely wrong convergence values which hurts this weapon over most others. If you set convergence properly and according to your fighting style then the .50cal can quite easily take apart enemy aircraft. Most of the .50cal armed aircraft have them in the wings...the idea is you want all of the wing guns to hit one point at a given range (thats the convergence). So if its 250m then at 250m all of the bullets from all 6 guns hit the same spot. If you're hitting a target at 250m but your convergence is at 500m (which is a much less effective range) then you're not getting a concentrated burst. Depending on the plane...maybe you're hitting the outside of both wings and not the important stuff like fuel tanks and engines in the middle.

My ideal convergence for machine guns is 250m. At that range, with a 6 gun .50cal arrangement, you can take a FW190 apart in 2-3 second burst. Sustained hits on the same location are usually best for obtaining results. If you're a spray and pray shooter and you tend to only land glancing blows then the bigger weapons are better as you can hope for a critical one hit kill. With the .50cal you need to poor rounds into the enemy like the real pilots did...it doesn't take many but some good shooting is required to take the enemy down quickly.

Also keep in mind that cannons specialize in material destruction so they take wings off or tail sections or blow engines to bits. Heavy machine guns tend to be focused more on killing the innards. So a few seconds and the enemy plane is basically done for and won't be able to fight or do much of anything but the plane is still basically intact.

Marcel_Albert
02-20-2007, 04:59 PM
I agree with you on P-40 airframe is too weak in Il-2 , especially its engine .

For the .50 cal , i think they are about ok now , well offline , i use 150 meters convergence , and it works pretty well offline , online it works too , but less effectively because of lag/packet loss , but still works fine .

Disadvantage of short convergence is that you can't shoot very far and make high and distant deflections (and not handy for head-ons ) like if you had 300 or 500m convergence , but it's clearly more effective at short range , you can often slice a wing or set the a/c in flames with 130/150 meters convergence on a Mustang , P-40 or Jug on your first pass .


IMHO and according to many videos i saw , .50cal should be a tad more effective in air combat , but i think that what we have now is much better than what we used to have before PF and quite close to reality .

ElAurens
02-20-2007, 05:10 PM
I second (or third) the comments about the P40's relative structural weakness in this series.

Real P40s were quite robust, and very fast in the dive. Our in game P40 is sort of robust and not all that fast in the dive.

Still my favorite aircraft overall however.

Marcel_Albert
02-20-2007, 05:21 PM
Indeed , quite a few veteran accounts also confirm this , the P-40 could take some severe punishment , it saved many lives , while in the game , it's quite a fragile aircraft sadly .

But before they "fixed" the Mg-151 , don't remember which patch , P-40 was still tough structurally ( except the engine ) ,but since then , it kinda slightly unbalanced the DM ingame , planes like Sturmovik or P-40 are more vulnerable and farther from their reputation of tough a/c , same for B-17 whom are brought down too easily with 20mil IMHO , but i think the Mg151 was too weak in the past to be honest , and after all it's a sim , they can't model perfectly all these complex stuffs , well just my humble opinion .

Xiolablu3
02-20-2007, 06:01 PM
The 50 cal is very good in current IL2/PF,

Its never going to be as powerful as 20mm cannon, or anything like the 30mm cannon, and you must get much closer, make sure you are shooting at around 200metres or less, thats 0.2 range.

Watch guncam footage of the 50 cals which has not been chosen especially for dramatic effect. The rare colour guncam footage is good for this, as it shows a 'typical' 50 cal attack rather than the explosive clips chosen for TV.

FOr example see how much damage there is in these clips and compare how close he is and how much damage is done versus the game. In my opinon, the game 50 cals are even stronger.

Se how many hits this 109 takes (I am sure its the same one, as it has the glycol leak it gets in the first attack all the way through each clip) from different P47's, yet he still comes in to land :-


http://raincoaster.com/2006/06/25/p47-guncam-footage-from-wwii-in-colour/


Ju88 attack from 50-100metres looks just like the game :-

http://www.zippyvideos.com/2680436834573326/ju-88_alcanzado/

Single FW190 takes a LOT of hits :-

http://www.web-birds.com/8th/339/gun/339-01.mpg

These were the first 50 cal clips I found after searching the net for p47 and p51 guncam, and are typical examples.

Japanese footage involves much more flames and explosions, thx to their planes lack of armour and self sealing fuel tanks..

Japanese Guncam footage, very much like the game :-

http://youtube.com/watch?v=La3qJ4sptuE


The 50 cals are devastating versus Japanese planes in the game too. German planes are more heavily armoured tho. Keep practising, and set your convergeance for you preffered distance.

What version of the game are you using?

leiker06
02-20-2007, 06:09 PM
you all make valid points. but, what i want to know is, if the game uses insindiary's or not. it wouldnt surprise if it did. because i've fought the japanese offline and those suckers just light up. but im wondering if thats the aircraft, like it was programed that way or if it's the bullets. because i've fought other aircraft online like the 109 and spit. and those rarely catch fire. the most damage i inflict is and black, smokey engine. which isnt bad, just guys usually steal the kill.

Xiolablu3
02-20-2007, 06:17 PM
Yeah thats an annoying hting about the 50 cals, its easy to have your kills stolen if you are on an 'Airquake' server'.

The Japanese planes have no self sealing fuel tanks or armour so they light up easily. I am not sure exactly what type of bullets are used in the 50 cal belts. I would htink it would be a mixture of API, HE and AP, but someone else will be able to tell us properly.

Better to find a nicer server where the guys will not jump in and shoot at your target if you are in a good position, but will cover your attack from above. ALso if you fly on Historical servers, rather than arcade ones, its often ALL US planes on the red side, so everyone has 50's. Therefore there is less 'Stealing 20mm cannon blasting away your kill after you pump it full of 50's'

WHat server settings do you like to play with?

leiker06
02-20-2007, 06:18 PM
i am using 4.04m. i know about what you guys are saying about convergance. i have mine set at 150 meters right now. i might change that to 200. and your right that the germans were better armoured, but they didnt have self-sealing fuel tanks did they?

leiker06
02-20-2007, 06:21 PM
i use to play in 334th server, but they resently went to 4.08 now i cant fly anywhere.

Xiolablu3
02-20-2007, 06:22 PM
Yes mate, all sides had self sealing fuel tanks from early int he war except for the Japanese who viewed a lighter more manouvrable plane more important. (they soon learned different later in the war)

I suspect you are playing on Arcade servers if oyu are using 4.04. Get Il2 1946 and join some of the more historical servers where you dont get 5 red planes chasing 1 blue. You will see that the 50's are good when the guys next to you arent trying to steal your target.


If you like the more relaxed settings with cockpit off, then try Ukdeciated1, that has relaxed settings but excellent historical maps. And most of the player will cover you if you are in a good position, not try and shoot your target. (you will always get a few noobs, but most are honurable)

I am sure there will bea few more 4.04m servers, get hyperlobby and ask in the chat.

Make sure you order IL2 1946, it has all previous content and the new stuff on one easy to install disc. No messing with patches/addons/etc.

If you were flying on the 334th server, then its no wonder you dont like the 50 cals, in fact the US planes dont shine at all on those kinds of server. Historical servers are totally different with regards to teamwork and tactics. Here the US planes are great. If you intend to keep flying on arcade servers then get used to the La7/Spitfire 25lbs/Yak3/Dora/Ki84 because these are the best planes in that situation. I would forget the US planes, these shine in a realistic scenario where each side has ground targets and bombers to cover, like on UKded/Warclouds/SPits VS 109's etc.

On these servers each side has ground targets and they have 1 hour to destroy them before the end of the map to win. Each side must cover their own troops and attack the enemies. It leads to some realistic tactics rather than just one big furball where the turnfighters reign supreme. Here the US fighters with their armour and heavy payloads really shine.

leiker06
02-20-2007, 08:06 PM
most of time i use the p-40 and the p-38 when i was flying in there for american fighters anyways. but i really, really did well witht the 109G-2. the greatest 109 ever!! http://forums.ubi.com/images/smilies/11.gif

Ratsack
02-20-2007, 09:57 PM
Originally posted by berg417448:
... This subject has been discussed many times before.

No!! You jest.

Ratsack

FritzGryphon
02-20-2007, 10:24 PM
All stuff aside, it is simple.

Historically, 3 M2 was roughly as effective as 1 Hispano. From anecdotal evidence, and USAAF report on weapon effectiveness.

In tests performed in the game, planes are shot down in roughly 4x as many 50cal bullets as 20mm shells. This is a ratio of 3-1 guns.

Do the test yourself if you don't believe it. Shoot down 20 planes with M2, then shoot down 20 planes with Hispano. Compare number of hits using user STAT.

On average, a generic fighter takes 2-8 cannon shells to kill, or 10-40 M2 bullets. Low end is for weak planes like Zero, and high end is for planes like P-47. These are generic values for firing at normal ranges with normal precision.

PBNA-Boosher
02-20-2007, 10:47 PM
Learn to shoot bub.

JG53_Valantine
02-20-2007, 11:27 PM
Originally posted by Xiolablu3:
I suspect you are playing on Arcade servers if oyu are using 4.04.

Just wanted to point out that not all 4.04m servers are "arcady" Theres a fair few that are historical with all german planes on Blue and all russian on Red. Admittedly there arnt as many of them as there are for 4.08 but i personally prefer the 4.04m version as theres a fair list of things that i dislike about other patches. I play full real in my campaigns, on hyperlobby i try to play on full real servers if theres one running, online with my squadron we play nearly full real except complex engine management and we have external views (no not wonder woman)
We fly with 109G2 - Leiker06 if your looking for a group then check out JG53 @ http://web.ncf.ca/fk467
- http://www.bombs-away.net/forums/forumdisplay.php?f=24

Going back on topic the 50cals are very weak against german planes purely because of the thicker armour then the japanese planes. Frontal attacks with 50cals work very well against most planes but takes nerves of steal to do with such a fast closing rate! also attacking from height works nicely if yo ucan get close enough in a dive.

VW-IceFire
02-20-2007, 11:34 PM
Originally posted by leiker06:
you all make valid points. but, what i want to know is, if the game uses insindiary's or not. it wouldnt surprise if it did. because i've fought the japanese offline and those suckers just light up. but im wondering if thats the aircraft, like it was programed that way or if it's the bullets. because i've fought other aircraft online like the 109 and spit. and those rarely catch fire. the most damage i inflict is and black, smokey engine. which isnt bad, just guys usually steal the kill.
The .50cal tracer round is a APIT. So its armor piercing, incendiary, and tracer all in one shot. The bullet type is present...you can see the flashes on the target when you hit (game engine graphics thing). If its working properly is another...but that may be more down to the target aircraft DM. Note that planes like FW190s and 109s tend to be less prone to flaming up than a Zero. Even a N1K-2J was far more resilient than a Zero and it weighed quite a bit more (like a US fighter nearly).

Kill stealing is another matter...and generally not the fault of the weapon type. All heavy or light machine guns will suffer the same issue. If its a arcade like dogfight server then by all means take the biggest guns you can fit or just don't worry about the kills.

Bearcat99
02-21-2007, 06:15 AM
The best way to actually see what you are hitting is to either go into arcade mode.. or record a track and then watch ther bandit as you hit him.. or not. You will be surprised at how much you miss when looked at from that perspective.

VV_Holdenb
02-21-2007, 06:35 AM
Good posts on this thread I, have learnt
a lot http://forums.ubi.com/images/smilies/25.gif

What option do you need to set to see the
"bullet" tragetories as red arrows in external view/ tracks ? That would will help with optimising convergence settings too.

otpisan
02-21-2007, 07:51 AM
Originally posted by VV_Holdenb:
Good posts on this thread I, have learnt
a lot http://forums.ubi.com/images/smilies/25.gif

What option do you need to set to see the
"bullet" tragetories as red arrows in external view/ tracks ? That would will help with optimising convergence settings too.

arcade=1

in config.ini file in Ubi folder. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

http://forums.ubi.com/groupee_common/emoticons/icon_cool.gif

Friendly_flyer
02-21-2007, 07:53 AM
Originally posted by leiker06:
you all make valid points. but, what i want to know is, if the game uses insindiary's or not.

We did some testing a month or so ago, using planes sitting on the ground shooting from tower mounted guns. The comparison was between LMGs and HMGs (typically the M2 in the later case). I think the consensus was that the hitting power of the .50 is a tad over the top, but the .30ies starts fire much more effectively. Personally, I think the .50 should have more incinidary effect, and possibly reduce it's hitting power. As it is, a 1 second burst from two M2's can actually rip the wing of a B-25, which I think is a bit in excess.

AVGWarhawk
02-21-2007, 08:28 AM
I set my .50 at 200m. Works great for me at .30 out. But what do I know, I'm just a gamer... http://forums.ubi.com/images/smilies/shady.gif

Blutarski2004
02-21-2007, 09:38 AM
Originally posted by Friendly_flyer:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by leiker06:
you all make valid points. but, what i want to know is, if the game uses insindiary's or not.

We did some testing a month or so ago, using planes sitting on the ground shooting from tower mounted guns. The comparison was between LMGs and HMGs (typically the M2 in the later case). I think the consensus was that the hitting power of the .50 is a tad over the top, but the .30ies starts fire much more effectively. Personally, I think the .50 should have more incinidary effect, and possibly reduce it's hitting power. As it is, a 1 second burst from two M2's can actually rip the wing of a B-25, which I think is a bit in excess. </div></BLOCKQUOTE>


..... I think that the overall damage effects of 50cal fire in IL2 are about as close as can be reasonably expected - in the sense that the average number of hits required to shoot down a fighter parallels the historical data.

OTOH, I agree that taking wings off with air-to-air 50cal fire was not historically common. Perhaps the static nature of the target in your tests permitted an unusally high concentration of hits in a single damage cell. Possible?

PFflyer
02-21-2007, 09:42 AM
I hit an a6m3 with a half-second burst from my P-40 today and it exploded like a bomb! Nothing left but flames and fragments. I don't think a hit from any cannon would have done any better job than that!

Your convergence must be off, I set mine to 150m.

R988z
02-21-2007, 10:01 AM
Disadvantage of short convergence is that you can't shoot very far and make high and distant deflections (and not handy for head-ons ) like if you had 300 or 500m convergence , but it's clearly more effective at short range , you can often slice a wing or set the a/c in flames with 130/150 meters convergence on a Mustang , P-40 or Jug on your first pass .




If you can hold your nerve, short convergence can be utterly devastating in a head on.

VV_Holdenb
02-21-2007, 10:21 AM
@otpisan: thank you http://forums.ubi.com/groupee_common/emoticons/icon_cool.gif

drose01
02-21-2007, 11:35 AM
I'm going to have to respectfully disagree that there is a "consensus" that .50s in game work as they should, at least in relation to the effectiveness of cannon.

I know that this is a dead horse, flogged incessantly, so I will stop here...

AVGWarhawk
02-21-2007, 12:01 PM
Originally posted by drose01:
I'm going to have to respectfully disagree that there is a "consensus" that .50s in game work as they should, at least in relation to the effectiveness of cannon.

I know that this is a dead horse, flogged incessantly, so I will stop here...

The cannon has an overwhelming advantage. The .50 seem fine to me also. It is never a dead horse. It is another opportunity for flaming to begin http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

Diablo310th
02-21-2007, 12:18 PM
changing the 50's loadout to api-api-api-api-apit would solve most if not all the problems with teh 50's assuming the incendiary values are correct.

AVGWarhawk
02-21-2007, 01:33 PM
Originally posted by Diablo310th:
changing the 50's loadout to api-api-api-api-apit would solve most if not all the problems with teh 50's assuming the incendiary values are correct.

Then on to the next moaning session....'Are the incendiary values correct?' yadda yadda yadda

Widowmaker214
02-21-2007, 02:30 PM
A very strong debate on this topic...
But if you really want to use the 50 cal effectively.. you have to get in close..and you need deflection shooting. Pure and simple. If you try and saddle up all you will do is chew up his tail section and perhaps get a lucky fuel tank burst. You'll waste alot of ammo.
You need to come in on at least SOME bit of an angle. Horizontal or vertical. Go for the wing roots/tanks or the nose and center of the fuselage. Get your bullets forward!
Correct convergence is just a given. Set them around 150-250 yards... which ever is your prefered shooting distance. I run mine between 200 and 250.

Incindeiary effects are best seen at less than 250 yards. They will do more "flamable" damage close in. Don't expect much from further out. And it does depend on the aircraft as well.

AVGWarhawk
02-21-2007, 02:38 PM
Originally posted by Widowmaker214:
A very strong debate on this topic...
But if you really want to use the 50 cal effectively.. you have to get in close..and you need deflection shooting. Pure and simple. If you try and saddle up all you will do is chew up his tail section and perhaps get a lucky fuel tank burst. You'll waste alot of ammo.
You need to come in on at least SOME bit of an angle. Horizontal or vertical. Go for the wing roots/tanks or the nose and center of the fuselage. Get your bullets forward!
Correct convergence is just a given. Set them around 150-250 yards... which ever is your prefered shooting distance. I run mine between 200 and 250.

Incindeiary effects are best seen at less than 250 yards. They will do more "flamable" damage close in. Don't expect much from further out. And it does depend on the aircraft as well.

Good one! I run mine at 200 meters to pretty good effect. Basically at .30 I fire, once the concentration of ammo hit the target, bye bye.

slappedsilly
02-21-2007, 03:04 PM
I have never shot a RL .50 cal. But I have seen the bullets and they aint little. The WW2 footage I've seen with .50 cal guns do look like they rip the planes up better than in the sim. I don't have any problem killing with them online but they usually just disable the plane or kill the engine and some bottom feeder put a few in on the way down, so all I end up with is a stolen kill. I've never seen a brit .303 but in the sim they seem to do better than the .50 cal. Some how that just don't seem right to me, but what the heck its a game so just get a different plane.

VW-IceFire
02-21-2007, 05:01 PM
.303's do better only in rate of fire and possibly due to the numbers of guns employed. The Spitfires IXc's four .303's are nearly useless compared to the twin .50cals on the IXe.

Xiolablu3
02-21-2007, 08:06 PM
There is no doubt that the 50 cals are more powerful than the .303's.

I really cant see much difference between the clips I posted of 50 cal fire and the game. In fact the game 50 cals seem more powerful , have you seen how close they are shooting in those guncams? If you get that close in the game, the enemy is going down after a 1 sec burst.

fordfan25
02-21-2007, 08:39 PM
Originally posted by Friendly_flyer:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by leiker06:
you all make valid points. but, what i want to know is, if the game uses insindiary's or not.

We did some testing a month or so ago, using planes sitting on the ground shooting from tower mounted guns. The comparison was between LMGs and HMGs (typically the M2 in the later case). I think the consensus was that the hitting power of the .50 is a tad over the top, but the .30ies starts fire much more effectively. Personally, I think the .50 should have more incinidary effect, and possibly reduce it's hitting power. As it is, a 1 second burst from two M2's can actually rip the wing of a B-25, which I think is a bit in excess. </div></BLOCKQUOTE>yet a FW190D can regualy absorb 70 even up to 120+ .50s and still fly back to base. yet if hit at the right angle a few will take a wing off strange how inconsistent DMs are when the .50 is used

Bull_dog_
02-21-2007, 09:43 PM
This argument introduces the B-25 damage model as a variable and is not valid....one could substitute an La-7, Fw or Beaufighter and reach the opposite conclusion.

Only Oleg knows the math involved...the damage modelling as a whole is better than other sims, but is sorely lacking in many areas making the whole conversation and debate rather difficult...

The effect of altitude on flammability is not modelled, there is substantial evidence that the loadouts for .50 cal weapons are historically incorrect, the inner parts of aircraft such as hoses, magnetos, struts, cables, radiators, oil and fuel lines are not specifically modelled, the effects of sharpnel and smoke/fire/oil in the cockpit are not modelled as well as pilot wounding and penatration of armor...I can't tell how that is done but there is certainly evidence that aircraft are very different....I see some aircraft that spout flames but are not damaged while others never catch on fire...ammo boxes don't explode when hit while other aircraft catch on fire and then the fire is mysteriously extinguished.....

When my hit % and kill ratio equals that of real pilots of similar experience and skill then I will know that the modelling is really good...right now that is not the case and I'll leave it at that. First thing I'd like to see changed is the bouncy instability of several aircraft dampened to increase hit % to reflect the real hit % and then I would comment on whether or not the .50's are accurate.

Right now, based on what I read, I suspect that I'm not getting the same hit% that real pilots with the flying hours that I have would have gotten...I feel the culprit is the fact that I fly with a joystick and don't feel any G-force and I am unable to keep the virtual plane as steady as a real plane.

I can't tell you how many virtual bullets I have fired, but it is probably in the millions so I make the assumption that I aught to be able to hit similar to real aces (about 10% based on a study I was made aware of) and my real % when I concentrate and don't waste ammo tends to be 4-6%

Blutarski2004
02-21-2007, 10:00 PM
Originally posted by Bull_dog_:
... the effects of sharpnel and smoke/fire/oil in the cockpit are not modelled as well as pilot wounding and penatration of armor


..... Engine fire = bail-out.

tigertalon
02-21-2007, 10:13 PM
If 9 out of 10 targets you shoot down with a .50cals go down for a reason different than being on fire, something must be wrong. 9 out of 10 should be on fire, not vice versa.

Bull_dog_
02-21-2007, 10:37 PM
Originally posted by Blutarski2004:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Bull_dog_:
... the effects of sharpnel and smoke/fire/oil in the cockpit are not modelled as well as pilot wounding and penatration of armor


..... Engine fire = bail-out. </div></BLOCKQUOTE>

There are several aircraft, mostly twins, that I can fly around with for a long time with the engine on fire.

Some aircraft, the Frank comes to mind, I just wait a bit and the fire goes out. Others, like the Ki-43 I do have to bail out but I can often wait a long time....the cockpits never fill up with smoke, my pilot is never burned, and hot oil never squirts me in the face....

One could model our virtual pilots without goggles since nothing ever gets in their eyes... We may be in violent agreement, but we may not be too...I cant tell from your post what your point was.

Blutarski2004
02-21-2007, 10:40 PM
Originally posted by tigertalon:
If 9 out of 10 targets you shoot down with a .50cals go down for a reason different than being on fire, something must be wrong. 9 out of 10 should be on fire, not vice versa.


..... A year or two back, when the great 50cal effectiveness debate was in full cry, I went through about 150 after action reports (from the book "America's Top WW2 Aces in Their own Words / Eighth Air Force") and collated all the descriptions of damage to e/a which were claimed as shot down. Fire was clearly observed on many occasions, but so were heavy black smoke from severed oil lines, heavy white clouds of leaking coolant evaporating off the engine, outright engine hits which stopped the prop, and a number of ooc's and spins attributed to PKs and/or shot-out flying controls. The rarest observed damage IIRC was the loss of a wing.

For whatever it's worth.

WWMaxGunz
02-22-2007, 05:15 AM
There seems to be one fire mode graphic, no small fire that automatic shutoffs caught the
leak on. But then soon after there should be engine trouble develop unless there is a
backup oil line. Are we to that level yet where the engine has a functioning model of
its own and not just detailed DM?

leiker06
02-22-2007, 11:46 AM
usually when i fly my hit % is in the range of 8 to 10% i dont waste ammo. and the distance i begin to fire is from .25 or .20 on in. my convergance is 150 meters. so i think im pretty close. i fly full real as well. i just dont see why if the americans had insindiary's that the fuel tanks in 109's and 190's or any plane wouldnt catch fire. hello, gas + hot metal bullet= should equal flames most of time.

AVGWarhawk
02-22-2007, 12:25 PM
I was hitting Ki last night and 9 times out of 10 they caught fire. My convergence is 200m and I start shooting at .30 out. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif I think the .50 are just fine.

HellToupee
02-22-2007, 01:03 PM
303s rip kis up, issues not the .50 but more the dm of many planes.

DKoor
02-22-2007, 01:25 PM
Originally posted by Marcel_Albert:
I agree with you on P-40 airframe is too weak in Il-2 , especially its engine . P-40 structural strength (as positive) is even mentioned in IL-2 in game object viewer.
But that is a crude joke, really. Especially if compared to some types.
Fact is that P-40 is one of the weakest fighters, as far as DM is concerned. And on top of that suffers from 7,62 engine insta-stoppage bug http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Vipez-
02-22-2007, 01:40 PM
P-40s have a nasty habit of loosing control cables with only couple of rifle caliber hits - be sure, this can be annoying.

P40s' Engine can be disabled with a single 7.92 mm hit. However, I don't see a problem with this, not any ww-2 era liquid-cooled engines made by any country were good at taking hits, radial engines clearly should have the advantage here. It should be different for some planes like JU-87D and IL-2s which carried additional armour plates to protect the fragile engine. It's more of some weird DM-modelling, some engines in the game (like Klimov 105 carried by Yaks/Laggs) have tendency to absorb huge amount of damage and still run fine.

AVGWarhawk
02-22-2007, 02:29 PM
Back on topic. If you aim for wing root or engine, the .50 are effective. Unfortunate they are not as effective as a cannon shell to the wing usually blowing it off. But, at the very least the wing hit by .50 makes the plane difficult to fly. At this point you can concentrate on the wing root, canopy or engine shot. Use the .50 at close range because the .50 looses velocity the farther it goes. Close up and it packs a wallop!

Set your concentration at close range and the .50 will do the job. http://forums.ubi.com/images/smilies/25.gif

WWMaxGunz
02-22-2007, 09:19 PM
Originally posted by leiker06:
usually when i fly my hit % is in the range of 8 to 10% i dont waste ammo. and the distance i begin to fire is from .25 or .20 on in. my convergance is 150 meters. so i think im pretty close. i fly full real as well. i just dont see why if the americans had insindiary's that the fuel tanks in 109's and 190's or any plane wouldnt catch fire. hello, gas + hot metal bullet= should equal flames most of time.

Regular bullet is not nearly that hot, it would melt first. It takes a spark to ingnite gas
fumes and air. Even a coal won't do, I've watched cigarette buts be put out in shallow gas
puddle just to show me. Of course with a not great shock, a cig butt mat knock a bit loose
that does flare up so they are not safe around gas fumes, a cigarette being inhaled on does
make many sparks and open flame inside. But the coal alone will not ignite gas fumes and\
a hot bullet (from gun barrel plus immense air friction which does soften lead tips) is
still nowhere near as hot as the coal let alone the spark or flame.

Now tracer or incendiary rounds, they can set fires.

Bearcat99
02-22-2007, 09:35 PM
Originally posted by Blutarski2004:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by tigertalon:
If 9 out of 10 targets you shoot down with a .50cals go down for a reason different than being on fire, something must be wrong. 9 out of 10 should be on fire, not vice versa.

..... A year or two back, when the great 50cal effectiveness debate was in full cry, I went through about 150 after action reports (from the book "America's Top WW2 Aces in Their own Words / Eighth Air Force") and collated all the descriptions of damage to e/a which were claimed as shot down. Fire was clearly observed on many occasions, but so were heavy black smoke from severed oil lines, heavy white clouds of leaking coolant evaporating off the engine, outright engine hits which stopped the prop, and a number of ooc's and spins attributed to PKs and/or shot-out flying controls. The rarest observed damage IIRC was the loss of a wing.

For whatever it's worth. </div></BLOCKQUOTE>

One other thing I noticed about a lot of the guncam footage I have seen was that there were a lot of bailouts... more than we see in the AI of this sim... IMO as far as the AI goes.. when a plane is set to smoking the AI should bail shortly thereafter. In reality not too many pilots would stay with a smoking plane for too long.... where there is smoke there is fire.. and no pilot wanted to risk having his O2 go up... or being fried in the pit... or passing out from the smoke and going down with the plane.. most decided to take their chances in a chute...

Xiolablu3
02-22-2007, 10:33 PM
If you can throw a cigerette into a puddle of petrol it goes out.

I guess it would have to be dedicated incendary ammo to set a plane on fire. Maybe Aviation fuel is more potenet than todays petrol tho?

Not sure tbh.

StellarRat
02-23-2007, 12:32 AM
"Maybe Aviation fuel is more potenet than todays petrol tho?"

No, I don't think so. Gasoline hasn't changed much since WWII other then the additives for octane that are used. If you're talking jet fuel, it is even less explosive.

An API bullet is much, much hotter than a cigerette. White hot in fact, and it doesn't need a source of oxygen to ignite. The oxidizer is part of the chemical that is used. If there is any chance of something catching fire it is hot enough to get it started. Gasoline fumes in a partially full tank would be extremely dangerous if hit by an API round. There is a chance of an explosion. At the least I would expect a fire, but it could go out depending on the speed of the plane and other factors. Hitting any
kind of ammo storage would be even more deadly because the fire wouldn't go out (ammo propellent doesn't need air to burn) and warheads for explosive rounds would probably start detontating in short order.

Blutarski2004
02-23-2007, 05:17 AM
Originally posted by Bearcat99:
One other thing I noticed about a lot of the guncam footage I have seen was that there were a lot of bailouts... more than we see in the AI of this sim... IMO as far as the AI goes.. when a plane is set to smoking the AI should bail shortly thereafter. In reality not too many pilots would stay with a smoking plane for too long.... where there is smoke there is fire.. and no pilot wanted to risk having his O2 go up... or being fried in the pit... or passing out from the smoke and going down with the plane.. most decided to take their chances in a chute...


..... Couldn't agree more, Bearcat.

AVGWarhawk
02-23-2007, 08:38 AM
@Bearcat,

Good point. Heck even I bail and I'm sitting in a computer chair http://forums.ubi.com/images/smilies/16x16_smiley-tongue.gif

I still find the .50 effective against Japanese aircraft. The Luftwaffen is a different story. The .50 do not seem as effective but I believe because 109/190 has better armor and sealing tanks. All in all, I'm happy with the .50 http://forums.ubi.com/images/smilies/25.gif

WWMaxGunz
02-23-2007, 09:26 AM
Smoke and/or flames do not get inside our modelled cockpits unless that's where pilot dies.
AI should bail sooner and smoke in cockpit would be cool even if windows opaqued first.
But then when we bail it is never a struggle with ctaching latches....

HarryVoyager
02-23-2007, 10:01 AM
Well, I've just been playing off-line missions, so I can't really comment on the online portion, but I've found that the 0.50 is an excellent weapon for disabling targets, but is a poor weapon for generating a clean kill.

Just a few minutes ago I was running a 4v4 P-47D (Late) v 109K-4 C3s. While we swept the 109's, none of the kills were outright. Every single 109 kill was an engine disable, typically either a trailing oil, or a coolant hit. The drill was to get a burst onto them until they started trailing, and then disengage that target, and then just wait for them to die. That's basically how you kill with 0.50 cal.

Radials are a bit more challenging, simply because they don't tend to have a convenient radiator to shoot out, however, I have noticed that the 190A seem to have grown an oil-cooler while I was away, and it now much more vulnerable to a good solid burst from head-on. (Quite the comforting thought, no?) And the F6F seems to have its oil cooler in the chin. I haven't fought the La-5/7 since I started playing again, but it looks like their oil coolers are in the wing roots and immediately under the cowl. Also, last I was playing, wood construction seemed to be especially vulnerable to heavy machine guns. That may have changed, but it might not.

Cannon, by contrast, tend to operate on the principle of taking a large enough divet out of a target that it structurally fails. This tend to lead to a much higher ratio of immediate clean kills, than the 0.50's crippling approach to combat. For extended anti-fighter operations, where individual kill-count isn't the core objective, I find that the ability for 0.50's to take a target out of the engagement with a small number of rounds tend to be for more effective than cannon's bust damage ability. (At least part of the reason we swept the 109K's so thoroughly was one of them exhausted his 30mm rounds early, without generating a kill, and had to break off, giving us a de facto numerical advantage.)

On the subject of incendiaries, one of the reasons aircraft non-self-sealing fuel tanks tended to be prone to detonation, is because they tend to be only partially liquid full in combat; the remaining capacity is taken up by *highly* ignitable gasoline vapor. The Zero was especially prone to this, simply because its range necessitated very large fuel tanks for its size, giving it a much bigger bang for its buck.

German and Russian aircraft are especially resilient to this effect, as they tended to have exceptionally small fuel tanks for their size and performance class, simply due to their very very short range.

On the subject of the P-40, performance tend to be relative. Against the Japanese pre-1944 fighters, it does have a superior dive and durable robust construction, provided you can protect the engine. Its armour, in general can stand up to the punishment IJA/IJN 7.62 and 12.6mm machine gun pairs can deal against it long enough for a wingman to cripple of kill a trailing Zero/Ki-43, and it has some solid survivability against the Japanese 20mm's if you can keep the hitcount down.

If you try that against German aircraft, you're screwed, because the 109 has enough armour to survive your wingman's pass long enough to make certain you aren't getting home, and the 1942-43 190s have a whole order of magnitude more firepower than anything you'd face in the Pacific, enough to make sure you wingman doesn't even get time to line up his pass.

The caveat is, in my experience at least, the P-40 is actually noticeably more maneuverable than either the 109 or the 190. If you can sucker them into a low altitude turn fight, suddenly, they have a problem. That, I think, really screws up a lot of virtual P-40 pilots; depending on which theater of operations you are in, you must use tactics that, where you in the other theater, would get you very dead, very quickly.

In DF servers, where you've got both a 190 BnZing you, and an A6M TnBing on you, you're just dead; you extend to BnZ the Zeke, and the Focke-Wulf unloads all the 30mm in the world into you, and if you sucker the 190, you've got a Zeke chewing up both your tails.

This is a lot of the reason I don't do Dog Fight servers anymore.

Harry Voyager

AVGWarhawk
02-23-2007, 10:15 AM
@Harry,

Yes, some DF servers do not attempt to keep plane sets relative to the place, date and planes that met each other. I create DF maps with specifically date and aircraft that fought against one another in that date. Seems kind of silly to have 190/109 and Zeros banging away at Hawks. Some DF servers are set up with date, planes that fought each other(Zeke v Wildcat) for one is a nice server. Anyway, as far as getting AI smoking, as Bearcat mentioned, perhaps more AI should be bailing more often when their plane is shot to hell. I do know that even if the .50 have a plane smoking and sputtering, it is out of action. Unfortunate you do not get the clean kill but still, the AI is done for. I have also noticed if you chew up a plane enough and this plane makes it back to base, it is damaged enough to award the kill. Thats fine but you do miss the plane exploding and debris going all over the place.

shotdownski
02-23-2007, 11:51 AM
As for gasoline and hot coals or cigs...it's mostly about vapor pressure and temperature. Liquid petroleum doesn't burn, petroleum vapors do. Higher temps mean more vapors (think evaporation), thus higher flamability. Cold gasoline is difficult to light, hot gasoline very, very easy. Don't go flicking your cig butts in puddles of gasoline unless you're in the Antarctic in winter. Note that some a/c (B-17s I think) diverted some of the engine exhaust gasses into the fuel tanks to displace gasoline vapors, thus lessoning the explosion hazard.

Another key factor in a/c fires is atomized fuel spewing from a puctured tank (think Concord). Atomized fuel should be very easily ignited and catastrophic.

Viper2005_
02-23-2007, 11:57 AM
Originally posted by Xiolablu3:
If you can throw a cigerette into a puddle of petrol it goes out.

I guess it would have to be dedicated incendary ammo to set a plane on fire. Maybe Aviation fuel is more potenet than todays petrol tho?

Not sure tbh.

Actually, that depends upon the fuel, the temperature and the cigarette... Do Not Try This At Home!!!

Actually, contrary to popular belief, because of its relatively high vapour pressure, the vapour above the fuel in a half-full tank of avgas is unlikley to be flammable unless it's very very cold.

At sea level temperatures the tank must be almost completely empty before the vapour space above the tank gets within the rich limit allowing combustion to take place.

JetA/Diesel type fuels have a lower vapour pressure and therefore actually cause more problems, though even then you need a fairly precise combination of circumstances to put the vapour within the flammable mixture range.

Fuel tank explosions are therefore relatively rare in aircraft.

I would expect instead to see fires starting outside the fuel tanks after holes are punched in the tanks.

Such fires would quite rapidly destroy the aircraft since Aluminium alloys rapidly lose strength above about 150ÂșC.

Usually however, fires actually kill via less obvious mechanisms:

1) toxic smoke in the cockpit kills the pilot

2) fire in the cockpit kills the pilot

3) fire burns through control rods/cables. If, for example, the elevator controls are disconnected in flight the nose will generally pitch down quite violently...

Typically only quite small fires are needed for these things to happen - no need for Hollywood Special Effects...

Usually burn times of 5-15 minutes are fatal, though there are exceptions, eg:


C. Discussion

1. This airplane caught fire in the air and was grounded before comparitive tests with other propellers could be conducted. One flight only was made with the hub cuffs removed from the A. O. Smith propeller. Results showed an increase of approximately 1 mph throughout the 12,000' cruising range.

2. Fire in the P-47D, Number 42-74616, resulted from a loose coupling on the left exhaust manifold adjacent to the turbo. The fire wall around the manifolds offered partial protection, however, the heat was intense enough to partially melt down the bulk head over the turbo, the left rudder pulley was burnt badly, the gasket on the air duct from the turbo to the carburetor was burnt away, and the fuselage skin and formers were warped from the break to the tail wheel.

2. Two thermocouples were installed on this airplane for the purpose of investigating temperatures in the fuselage resulting from the standard turbo installation; one was suspended approximately 2" ahead of the tail wheel, and the other adjacent to the push-pull rod directly over the turbo. The highest temperatures obtained under all flight conditions with the thermocouples in these positions were as follows:

Tail wheel temperatures of 150?C were obtained at take-off with the tail wheel in the down position. Under all other flight conditions the maximum tail wheel and push-pull rod temperatures were 50?C and 60?C respectively.

For further investigation the push pull rod thermocouple was moved to a position on the bulkhead over the turbo adjacent to the right rudder cable pulley. When the break occurred, this thermcouple read 150?C even though the broken manifold was on the other side of the fuselage. The pilot closed the turbo at the sign of smoke, but fully opened the turbo several times in order to investigate the cause. It is believed that this greatly increased the damage first done to the airplane.

Any simultaneous occurrance of smoke with high thermocouple temperatures and zero tachometer readings with subsequent drop in manifold pressure should immediately warn the pilot to close the turbo and to leave it in the "off" position.

http://www.wwiiaircraftperformance.org/p-47/p-47d-74616.html

It is unlikely that this fire would have been dramatic to look at - the pilot didn't even know about it until after landing. But the damage done was sufficient to ground the aircraft. The chances are that in a less sturdily constructed aeroplane than the P-47 (which also used a fair bit of steel in its construction) the results would have been rather less happy for all concerned...

This sort of fire could be started by a single round puncturing an exhaust manifold - no incendiaries required.

GR142-Pipper
02-24-2007, 01:39 AM
Originally posted by Xiolablu3:
I suspect you are playing on Arcade servers if oyu are using 4.04. Get Il2 1946 and join some of the more historical servers where you dont get 5 red planes chasing 1 blue. You will see that the 50's are good when the guys next to you arent trying to steal your target. The arcade servers do provide a useful function for those building their skills to play on full real servers as well as those who already play on them....specifically, building maneuver and gunnery skills. The problem with the "historical" servers is that the action is typically so glacially slow that new pilots just aren't going to build their gunnery and/or flight abilities there. IMO, it's best to learn how to fly and fight on an arcade server. That way when it comes to flying on the "historical" servers it will be more manageable as they're primarily BnZ anyway.

GR142-Pipper

Xiolablu3
02-24-2007, 04:22 PM
I agree you get more action to practise gunnery in arcade servers, but there are some great historical action packed servers.

You should check out Ukded2, that has Cockpit on, Externals on, and the maps are designed so that the action is thick and fast for bombers/fighters and Jabos.


Its all in the map design http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

My fav UKded map right now is a fantastic map made by ICefire, which has B29's attacking a Japanese ISland from high alt 4000m (airstart for Yanks). Escorted by P47's,P51D's,Hellcats,Corsairs. The Japanese must get airbourne and defend in Ki84/J2M3/Zeros/N1K2.

Its absolutely amazing, the P47 is my plane of choice on the map, it rips up the Japanese planes.

There is never a lack of action on these servers, and they manage to stick to mostly historical planesets and scenarios.

Great job on the map Icefire.

BTW Astro, or anyone else. Map suggestions are most welcome, they have af orum just for this. CHeck out the detail and tweaking in order to make a great map.

Spec and development thread for Hastings for example...

http://www.battle-fields.com/commscentre/showthread.php...6&highlight=hastings (http://www.battle-fields.com/commscentre/showthread.php?t=10896&highlight=hastings)

Forum :

http://www.battle-fields.com/commscentre/forumdisplay.php?f=70

WB_Outlaw
02-24-2007, 05:06 PM
Originally posted by Viper2005_:
Actually, contrary to popular belief, because of its relatively high vapour pressure, the vapour above the fuel in a half-full tank of avgas is unlikley to be flammable unless it's very very cold.

At sea level temperatures the tank must be almost completely empty before the vapour space above the tank gets within the rich limit allowing combustion to take place.

JetA/Diesel type fuels have a lower vapour pressure and therefore actually cause more problems, though even then you need a fairly precise combination of circumstances to put the vapour within the flammable mixture range.


Viper,
I haven't double checked but I think you have the Diesel/Gasoline backwards with respect to vapor pressure. Gasoline is much more dangerous than diesel when it comes to explosions. IIRC, that's one of the reasons tankers hated running gas engines so much.

I'm going to double check when I get a chance and I'll post some numbers.

--Outlaw.

AVGWarhawk
02-25-2007, 06:14 AM
Originally posted by WB_Outlaw:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Viper2005_:
Actually, contrary to popular belief, because of its relatively high vapour pressure, the vapour above the fuel in a half-full tank of avgas is unlikley to be flammable unless it's very very cold.

At sea level temperatures the tank must be almost completely empty before the vapour space above the tank gets within the rich limit allowing combustion to take place.

JetA/Diesel type fuels have a lower vapour pressure and therefore actually cause more problems, though even then you need a fairly precise combination of circumstances to put the vapour within the flammable mixture range.


Viper,
I haven't double checked but I think you have the Diesel/Gasoline backwards with respect to vapor pressure. Gasoline is much more dangerous than diesel when it comes to explosions. IIRC, that's one of the reasons tankers hated running gas engines so much.

I'm going to double check when I get a chance and I'll post some numbers.

--Outlaw. </div></BLOCKQUOTE>

Yes, diesel, the bottom of the barrel, will ignite through high compression. Gasoline is much more combustible. Gasoline in a liquid state is not bad but in a vapor state, look out. It is the vapors that ignite and burn. For example, the automobile industry has found that 14.1 parts O2 to 1 part gasoline is the most efficient burn. How is this mixture obtained? Through carborations and fuel injection. The latter more efficient. The carborator/fuel injector create a mist/vapor of the gasoline. it mixes with O2 and sucked in to the piston chamber, ignited and pushed out the exhaust on the final 4th stroke of that piston.

Anyway, the vapor trail of a leaking aircraft is quite volatile. Not to mention the vapor getting caught in pockets of the wing, fuselage and cockpit. One incindiary can ruin a whole day. Also, I believe the incindiary would not go out once it hits the plane. It would burn for a time. So perhaps it was two fold...light up vapor from gasoline and ignite materials that are part of the aircraft structure.

Now, some might say that aviation fuel is much more volitale than regular gas. I believe it is as the octane rating was much higher. I believe Jimmy Dolittle came up with this formula. From my understanding, when lower octane gas hits a hot surface it tends to ignite and leave hot spots on cylinder wall. This produces knock and pings because the gas/O2 mix is igniting before the compression stroke. It is found that low compression engines did not need high octane because the predetonation would not occur. Your car is a perfect example. Usually compression is 8:1. Your older cars(muscle cars) had factory compression of 13:1. These vehicles needed higher octane to prevent predetonation. Aircraft engines of the time were much the same, high compression engines. Dolittle found that high octane performed better in these engines. I will have to re-read my book on Dolittle for this point.

Outlaw is right, I have read plenty of books on German U-boats and their victims. The merchant men were not a big fan of transporting fuel. Usually the merchant was not totally loaded with fuel and the sailors would hope the torpedo would hit a hold that was ladened with anything other than a substance that burned. Most often the u-boat Kaleuns were so aggressive that it did not matter anyway. These Kaleuns would go after the vessels with impunity assuring a sinking. Of course this was during the "Happy Times" were ASW was not so great. Later on it was a different story.

WWMaxGunz
02-25-2007, 07:33 AM
I can pour a long trail of gasoline on warm pavement and light off one end of it,
the flame will begin to propagate at 100 mph let alone over 200 kph. Inside the
plane is a different matter but I don't think that IL2 models fuel leaked inside
the plane as a fire hazard.

WB_Outlaw
02-25-2007, 10:11 AM
Originally posted by AVGWarhawk:
Your older cars(muscle cars) had factory compression of 13:1. These vehicles needed higher octane to prevent predetonation. Aircraft engines of the time were much the same, high compression engines.

13:1 is a VERY high compression ratio for a gasoline engine and I'd bet would require an insanely high octane gas or some type of charge cooling. Diesels run higher CRs (greater than 15 in some cases IIRC) b/c the heat that ignites the fuel comes from compression. Supercharged WW-II aircraft engines were fairly low compression, around 7.5:1 I believe.

--Outlaw.

AVGWarhawk
02-25-2007, 12:38 PM
Here is a good article on octane/compression/water injection

http://www.rallycars.com/Cars/WaterInjection.html

Here is another:
http://www.nagel-engine.com/tech.html


Looks like you are correct on the 7:1 ratio.

Judging by these articles the aircraft still experienced detonation when fuel entered the chamber apparently do to supercharging.

Both good articles.

I

Blutarski2004
02-25-2007, 04:40 PM
Originally posted by WB_Outlaw:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by AVGWarhawk:
Your older cars(muscle cars) had factory compression of 13:1. These vehicles needed higher octane to prevent predetonation. Aircraft engines of the time were much the same, high compression engines.

13:1 is a VERY high compression ratio for a gasoline engine and I'd bet would require an insanely high octane gas or some type of charge cooling. Diesels run higher CRs (greater than 15 in some cases IIRC) b/c the heat that ignites the fuel comes from compression. Supercharged WW-II aircraft engines were fairly low compression, around 7.5:1 I believe.

--Outlaw. </div></BLOCKQUOTE>


Chevrolet 427 L71 - 11.25:1 compression ratio
Chevrolet 427 L88 - 12.00:1 compression ratio
Plymouth 413 Max Wedge - 14.00:1 compression ratio


Only the L71 was really streetable on pump gas. The L88 and Max Wedge were both really race-only motors.

AVGWarhawk
02-25-2007, 05:10 PM
@Blut

Yep, I built a Windsor 351 with Chevy flat top pistons. Compression was 13:1. Detonation was a very real thing with this motor. High octane gas and timing adjustment got some out but all in all, water injection of some sort would have been nice. I sold the car (65 Mustang) so it did not concern me anymore.

Anyway, I believe the high octane/water injection to handle the supercharges on aircraft engines in WW2 service. I'm digging around for imformation on it.

WWMaxGunz
02-25-2007, 07:49 PM
J.C. Whitney (are they still around?) used to sell water injection kits......

WB_Outlaw
02-25-2007, 09:17 PM
Originally posted by AVGWarhawk:
@Blut

Yep, I built a Windsor 351 with Chevy flat top pistons. Compression was 13:1. Detonation was a very real thing with this motor. High octane gas and timing adjustment got some out but all in all, water injection of some sort would have been nice. I sold the car (65 Mustang) so it did not concern me anymore.

Anyway, I believe the high octane/water injection to handle the supercharges on aircraft engines in WW2 service. I'm digging around for imformation on it.

There were a variety of methods used to control the high temperatures caused by the high charge pressures in WW-II aircraft engines. If an intercooler wasn't enough then water and/or alcohol injection were often used. Nitrous oxide also did double duty in that it cooled the incoming charge and added more O2. Of course you have to be careful with the Nox b/c the extra O2 can rapidly increase combustion chamber temperatures to unacceptable levels.

IIRC, the Super Corsair that used to race at Reno (before the fire and subsequent loss of the aircraft) had a 300 gallon water tank that was empty at the end of the very short race. I'm not sure what the boost pressure was but I think it was just short of a billion PSI.

--Outlaw.

AVGWarhawk
02-26-2007, 06:50 AM
I do know that higher octane fuels burn slower than the lower octanes. As a result, the higher octane does not ignite when it contacts hot piston walls and piston itself(this create knock and headache when a hole is blown throw the top of the piston).

Nitro...I messed with the bottle once. Chevy big block bored to 468CID/tunnel ram/two 850 Holley double pumpers. Motor ran nice. I hit the juice and my double roller timing gears went south along with the motor. http://forums.ubi.com/images/smilies/16x16_smiley-mad.gif I had the motor in a corvette that was all glass/tubed/tunneled. 4 link rear. 8.90 car on the 1/4 mile. Grew up, had kids, sold car. End of story.


300 gallons of water!!!! That was a lot of weight to haul around! I bet it was empty at the end. Talk about power!!!! I suspect the aircraft left an impression on your arse http://forums.ubi.com/groupee_common/emoticons/icon_eek.gif Shame to see them go up in flames.

Sergio_101
02-28-2007, 04:41 PM
Ok, myth busting time.

Typical Diesels run from 16:1 to 22:1 compression.
Higher compression than 22:1 is rarely used as
the trade off in parasitic power loss
and reliability means it is not worth it.

In non supercharged racing engines it is not
at all uncommon to see compression ratios up to
16:1. I have built a couple of SB Chevys with 16.4:1
for drag racing. They require some extreme measures
to keep them together.
I have also run a 13.4:1 compression street/strip motor.
It's possible, but NOT advisable. 100LL or VP16 race gas
mixed with premimum unleaded is needed.

Water injection will reduce power in any engine if
there is no boost or compression increase with it.
In an non supercharged engine Water Alchohol injection
is taboo, just a good way to ruin an expensive motor.

As to the topic of this thread. The Soviet/Russian 12.7MM
is basicly the ballistic twin of the US .50. Each has
some minor advantages over the other. But they are 99% the same
in performance.

Note how the russian 12.7 performs compared to the US .50.....
Need I say more?

Sergio

AVGWarhawk
02-28-2007, 05:04 PM
I never did run CAM2 racing fuel in the 351. The bottom half was built for nitro. Balanced and blue printed. Like I said, sold it of for other things in life.

I never played with alcohol. I leave that the NHRA professionals!!!!!!

ImpStarDuece
02-28-2007, 06:26 PM
Originally posted by Sergio_101:
Ok, myth busting time....

<snip>

As to the topic of this thread. The Soviet/Russian 12.7MM is basicly the ballistic twin of the US .50. Each has some minor advantages over the other. But they are 99% the same in performance.

Note how the russian 12.7 performs compared to the US .50.....
Need I say more?

Sergio

Hmmm, yes, you do need to say more, particularly when you ignore the facts.

The UB fires a heavier round (15% heavier) with more than twice the HE/Incendiary content (.85 grams vs 2 grams) at higher rpm (850-1100 rpm, depending on whether the gun is syncehed or not) and only slightly lower muzzle velocity (about 5% lower).

In terms of 'horsepower" per gun, it should be about a third more effective.

Don't believe me, then lets look at some armament experts opinions (Tony Williams and Emmanuel Gustin, authors of "Flying Guns of WWII"):

Tony Williams: "Round power"
M2 (12.7x99): 4.6
UB (108x99): 5.7

i.e. UB does approximately 20% more damage per round

"Gun efficiency"
M2: 2.1
UB: 3-3.9 (depending on synched or non-synched fire)

i.e. UB is approximately 40%-85% more efficient.

Emmanuel Gustin:

"Q" factor [(KE x RoF)/Weight]:

M2: 7.7
UBK (synched): 10.3
UBS (unsynched): 13.5

i.e. UB is approximately 33%-75% more efficient

"M" factor (mass output/weight):

M2: 19.9
UBK: 27.7
UBS: 36.4

i.e UB is approximately 40%-80% more efficient

Wow!

So the UB fires a round that is 20% more destructive, and does so anywhere from 33%-85% more efficiently.

Now, what were you saying about the two guns being "99% the same in performance"?

WWMaxGunz
02-28-2007, 07:25 PM
From Oleg's Guns and Ammo chart:

.50 Browning: all bullets mass .0485, speed 870, APIT explosive TNT equal .002

UBS/UBT: APIT mass .0448, speed 850, explosive .001; AP mass .051, speed 850 explosive 0;
UBS/UBT: HEI mass .0428, speed 850, explosive .00114 + .00128 (HE + I)

Nothing about ROF but UBS unsynch is good deal higher than .50 Browning.

Not much to choose from except IIRC 50% higher ROF of UBS makes that the better choice
without going to mass of the guns themselves.

FritzGryphon
02-28-2007, 07:36 PM
Maybe this is interesting. Side by side comparison of UB and M2 tracer bullets in game.

http://members.shaw.ca/evilgryphon3/compare.mov

The furthest air race marker is 2km. The barrage balloons are at 100m. Shots were fired horizontally, at 0 airspeed.

---


And just the M2 by itself. The average speed values are wrong, btw.

http://members.shaw.ca/evilgryphon3/m2ballistic.mov

Xiolablu3
02-28-2007, 09:37 PM
I was talking to an aircraft arms expert a few months ago, and he said of all the Allies in WW2, the Russians were far ahead in their development of cannons and heavy machine guns than the Western Allies.

Generally all of their near equivelent weapons, LMG .303, HMG .50, 20mm, 37mm were more effective than their western equivelents when you factor in weight of the gun and weight of fire.

Sorry I cant elaborate any more than that, we didnt get too deep into it.

I presume he's correct because he knows his sh*t on WW2 stuff.

Although the German HMG was not as effective as the rest of the nations, when you factor in its weight, I think its quite good, isnt it? I seem to remember the MG131 being very light for a HMG. WHo needs a HMG when you have 20mm and 30mm cannons that small tho!

WWMaxGunz
03-01-2007, 12:46 AM
I was watching one of those TV shows from one of those cable channels and this one was about
Allied planes doing ground attack. One of the US guys flew a P-47 and he was talking about
the .50 tracers while they rolled guncamera footage of a train attack.

He said flat out that the tracers were good because when they hit you know where they're hitting.
He said that while in the film the plane was shooting in daytime and the only sign of tracers
were big bright flashes as they hit the target. His name is Fred Krause.

I did see a few clips where yes I could see the tracers paths as moving white lines (B&W film)
at a close angle to the path of the plane but for those few there were many where maybe a bit
of tracer flight was there or not and so quickly the flashes where they hit. I am thinking
that perhaps lighting conditions may be the difference, would shutter time or F-stop be changed
by ground crew?

Just from about 20 or so clips of US fired tracers, I saw both no path and tracer paths both
but always-always the nasty big flashes where they hit. IMO those should light fuel and oil
up pretty well maybe even 1/2 meter or more from the strike. Even with only 1 tracer in a
few rounds the flashes were like drumrolls.

Ratsack
03-01-2007, 12:57 AM
This was one of the things that CFS2 did very well. The flashes of bullet strikes were actually very good. The tracers themselves looked like sh1te, but the impact flashes were very good.

cheers,
Ratsack

Fork-N-spoon
03-01-2007, 01:56 AM
Regarding bullets lighting gas tanks on fire...

I've personally machine-gunned fuel tanks numerous times. Be the tanks half full, nearly empty, full, empty, hot day, cold day, windy, dry, damp, incendiary ammo, tracers, add infinum, the gas tanks never caught fire. While I've machine-gunned gas tanks with various machine guns, the one I used the most was a Maxim 8mm belt fed water cooled machine gun. I shot up dozens of gas tanks, frequently running 200 round belts through the tank, meaning sustained fire, about 20 seconds. Repeat, the gas tanks never caught fire, even with tracers and incendiary 8mm ammunition. All the tanks were ferrous metal and the bullets were steel cased Chinese made circa 1950. Repeat, the tanks never caught fire.

Fuel tanks blowing up because 1 round from a 9mm pistol hit the thank is nothing more than Hollywood rubbish.

Blutarski2004
03-01-2007, 05:51 AM
Originally posted by Fork-N-spoon:
Regarding bullets lighting gas tanks on fire...

I've personally machine-gunned fuel tanks numerous times. Be the tanks half full, nearly empty, full, empty, hot day, cold day, windy, dry, damp, incendiary ammo, tracers, add infinum, the gas tanks never caught fire. While I've machine-gunned gas tanks with various machine guns, the one I used the most was a Maxim 8mm belt fed water cooled machine gun. I shot up dozens of gas tanks, frequently running 200 round belts through the tank, meaning sustained fire, about 20 seconds. Repeat, the gas tanks never caught fire, even with tracers and incendiary 8mm ammunition. All the tanks were ferrous metal and the bullets were steel cased Chinese made circa 1950. Repeat, the tanks never caught fire.

Fuel tanks blowing up because 1 round from a 9mm pistol hit the thank is nothing more than Hollywood rubbish.


..... Interesting. But how then do we explain the highly flammable behavior of Japanese a/c under 50cal fire?

shotdownski
03-01-2007, 09:45 AM
Originally posted by Blutarski2004:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Fork-N-spoon:
Regarding bullets lighting gas tanks on fire...

I've personally machine-gunned fuel tanks numerous times. Be the tanks half full, nearly empty, full, empty, hot day, cold day, windy, dry, damp, incendiary ammo, tracers, add infinum, the gas tanks never caught fire. While I've machine-gunned gas tanks with various machine guns, the one I used the most was a Maxim 8mm belt fed water cooled machine gun. I shot up dozens of gas tanks, frequently running 200 round belts through the tank, meaning sustained fire, about 20 seconds. Repeat, the gas tanks never caught fire, even with tracers and incendiary 8mm ammunition. All the tanks were ferrous metal and the bullets were steel cased Chinese made circa 1950. Repeat, the tanks never caught fire.

Fuel tanks blowing up because 1 round from a 9mm pistol hit the thank is nothing more than Hollywood rubbish.


..... Interesting. But how then do we explain the highly flammable behavior of Japanese a/c under 50cal fire? </div></BLOCKQUOTE>

My guess? Atomized fuel, fuel from a holed tank or fuel line in the airstream is more easily ignited. Kind of like how a carbarator works.

WWMaxGunz
03-01-2007, 11:04 AM
Originally posted by Blutarski2004:
..... Interesting. But how then do we explain the highly flammable behavior of Japanese a/c under 50cal fire?

Burning tracer material on thin magnesium skin?

You know how to tell historic film of a burning Zero from recreation? In the historic film,
the Zero shines so bright it overwhelms the film like a small sun falling and the recreation
does not at least so far I haven't seen the blaze CGI'd in.

Monguse
02-26-2008, 06:09 AM
Posted:
http://forums.ubi.com/eve/forums/a/tpc/f/63110913/m/8231039685/p/2

1c Bannana Forums
http://forum.1cpublishing.eu/showthread.php?t=2830

BOA_Allmenroder
02-26-2008, 07:22 AM
Originally posted by Fork-N-spoon:
Regarding bullets lighting gas tanks on fire...

I've personally machine-gunned fuel tanks numerous times. Be the tanks half full, nearly empty, full, empty, hot day, cold day, windy, dry, damp, incendiary ammo, tracers, add infinum, the gas tanks never caught fire. While I've machine-gunned gas tanks with various machine guns, the one I used the most was a Maxim 8mm belt fed water cooled machine gun. I shot up dozens of gas tanks, frequently running 200 round belts through the tank, meaning sustained fire, about 20 seconds. Repeat, the gas tanks never caught fire, even with tracers and incendiary 8mm ammunition. All the tanks were ferrous metal and the bullets were steel cased Chinese made circa 1950. Repeat, the tanks never caught fire.

Fuel tanks blowing up because 1 round from a 9mm pistol hit the thank is nothing more than Hollywood rubbish.

That's because the fuel tanks you shot probably were not pressurized.

Once you pressurize the fuel cell and hit it with something hot: boom, fire.

Tater-SW-
02-26-2008, 07:37 AM
While I'm usually not a huge fan of the quality of the experiments done on mythbusters, they fired tracers and incendiary into a propane tank, and no fire. Then they borrowed a minigun with incendiary ammo and it made quite a boom.

Friendly_flyer
02-26-2008, 07:53 AM
Originally posted by BOA_Allmenroder:
Once you pressurize the fuel cell and hit it with something hot: boom, fire.

It's not like a pressurized tank will blow up. It's more likely to do so that an unpressurized one (which, like Fork-N-spoon reported isn't likely to start burning at all), but that doesn't mean it will it will blow up automatically if pierced by a hot bullet.