Friday 2010-12-10 Dev. video update and Discussion
 

Hi,

I promised to post videos some time.
Here is the first of them.

1. Engine start. Flame and smoke effect. Every start is different (in realtion to emulation of real engine cylinders work by a program).
Sound is currently a place holder. Unfortunately I wasn't able to record in a track at the moment maximal settings (some unpredictable bug in recording of video need to be found and eliminated )

http://www.youtube.com/watch?v=G836qqOhhZ8

2. Effect of exhaust flame at night time. Emulation of each cylinder exhaust in relation to emulation of real engine cylinders work by a program.
My question to community: isn't it too yellow? Maybe to add a bit red color in a mix with yellow? It is tunable really, so I would like to listen suggestions

http://www.youtube.com/watch?v=KTx5v8jeFdw

awesome...maybe a little red or orange would be good.

Well this is not a british engine but maybe this gives you an idea how it should look like?
http://www.youtube.com/watch?v=4ZzvKCQwWj0

Very nice update! Videos are always so much more than still pictures.. :D
Yeah, maybe a little too yellow.. should it not be more white rather than redish?
[EDIT] ok.. after seing Wutz vid of the DB.. (I wasn't way off with "more white") I change my mind to whitish-blue ;)

Sweet, thanks Oleg.

Yes a bit too yellow, needs to be turned down and perhaps blue after effects added like in the video Wutz linked too...

Way too small detail to worry about...release the game as it is :-P!

I would go more with Blue...

Hello Oleg --

many thanks for the update !

Yes, I think it's too yellow. It should actualle be more white/blueish, like in the DB 605 engine video posted above. But I have to admit that I have no idea what the difference from engine type to engine type makes.

In all of the accounts I've read, the pilots refer to Blue flames from the exhausts at night.

The flames matching the firing order is very impressive!:grin:

Excellent work. Probably less yellow.

RedToo.

No, this doesn't give me idea... Load the sound file from this video in a professional sound edit program and look for the spectrum... You will see there soo poor range and will be very impressed if you will load the same from a track above (our), even it is a place holder yet...

However I see the color of exhaust here in DB. Interesting with which gazoline and settings for start :) Becasue exaust color depending of many-many "settings".

:) WOW ,Thanks Oleg.Tunable colours and pistons firing imprecisely according to differing conditions that sounds good.
Will the engine be able to be made to misfire due to poor management inflight or due to damage?
LOL :) I wonder if the groundcrew can be singed and made sooty by backfiring engines :)

Sorry Oleg I did not mean the sound, but the exhaust flames coming out. Sorry if I did not state that clear enough.

It is depending of gazoline, pressure, RPM, and so many other factors... Even at different altitudes it is different really...

We have original table of the exhaust colors by which British crew were need to define is in good or not so good conditions the engine before the flight...

Hello Oleg!

If there is a program managing each exhaust pipe individually, could it be possible to expand it in order to make the exhaust flames yellow + puffs of black smoke + irregular firing tending quickly toward blue + no smoke (or slight stream of translucid grey), as Wutz video shows?
Exhaust flames at high RPM were indeed blue (assuming the pilots were managing mixture, which was generally the case!)

JVM

Don't forget the cooling effect of the exhaust stacks on the spit. I don't have a video to hand but you would have much cooler unburned fuel flames with this type of exhaust than with the straight stacks on the Daimler engine. I'm actually of a mind with Oleg, that the flame needs to be "cooled down" a little.

Blueish. Daimlers burn very rich though and burn low grade fuel, 87% octane. Would they still burn that now? They had much lower compression ratios than merlins but they were made that way because the Germans didn't have access to the good fuels that the allies had. Lower compression engines run well...better one low grade fuels than they do on high grade fuels. It's probably why they had such a bigger displacement than Merlins 27 I think and 34 liters. Bigger displacement to get the power.

Attention
 

I need immediatly to run from office.

Please if you find any materials that to show, read, and you own suggestion - write it here.
I and my guys will read it.

I will be back soon. Hope on Sunday.

Very impressive effects Oleg, thanks:grin:. I love the fact that you worry about little details like this. Will the engine require more turns of the prop sometimes before starting? Will we sometimes have to try twice to start it like in the DB video?

Thanks for taking the time to update us. It is appreciated.

Ok, but even if it's dependent on those factors, and there would be set of factors that would produce yellow colors like in the video you posted, it's still too yellow. Actually, the problem is (as far as I can see in compressed video) that the spectrum is too narrow. There should be a wider range of subtle hue/value (not saturation) difference in the different flames as they appear, in some random pattern.
It's however hard to tell -- who knows what the video codec does, and then it's that everyone has a different monitor. I played it however on my color calibrated Wacom Cintiq, and that is what I thought first.

Agree that most accounts I've read also mention intercepting at night by spotting blue flames.

Looks like my thread did the trick:rolleyes:

Thanks Oleg

S!

Thank you for the update :) Nice to see things shaping up. In that DB605 video you can see the root of the flame has reddish/yellow but the tip of it is blueish. Could the British and German difference be that Brits and other allies had carburettors and Germans had direct fuel injection in their DB/Jumo/BMW engines. The mixture in a fuel injected engine, like DB-series, is better than in a carburettor engine and high pressure spray of fuel gives more even fill of the cylinder at the right time compared to the suction in a carburettor system.

Also many nightfighter books I have read state blueish flames on British bombers. And there was a talk witha guy who tuned/maintained DB engines and he said the engine tunes were done in a dark room to see the exhaust flame color to adjust the injection etc. correctly.

Ok, have a good weekend all! :)

Merlin V12 Startup, I see a lot of blue

http://www.youtube.com/watch?v=Aqrbt...eature=related

GREAT , GREAT , Pictures and this in motion. :grin:

Thank you so much for this great Friday update. With every Friday evenning beats our hearts a little bit more for this great Game:-)

I think we all wish you, your famaly and your team too.. a nice peacefull christmastime and a happy new year 2011.

Thank you Mr. Oleg


with regards from Old Germany

Here is a Merlin engine being started, but one see no flames at all, maybe only visable during night time?
http://www.youtube.com/watch?v=yprfH...eature=related

Oleg.....Spitfire flames in the dark and they are blue!!


http://www.youtube.com/watch?v=QhFAwSk9Vqg

:) Do these help
http://www.youtube.com/watch?v=AqrbtxcNqbM

http://www.youtube.com/watch?v=3arJP...eature=related 7 mins in

http://www.youtube.com/watch?v=k9AGb...eature=related 3 mins in for night time CREDIT TO THE AUTHORS OF THE VIDEOS

Don't forget that in the Daimler video, (as far as it seems to me) they were starting the engine for the first time, so they went straight into a "break in run" at a much higher than Idle RPM. (it's been a long time since I've built an engine, but I think I'd typically "run in" a chevy big block at about 2000 RPM for about 15 minutes) That kind of RPM will of course produce a hotter flame than a typical start to idle of an already broken in engine. This will also (as Oleg pointed out ) explain the difference between the flame seen at start up and in flight.

Big LOLs. Oleg sure has his work cut out for him. I'd not be surprised if this thread doesn't cure him from appeals to us for help!

Re exhaust stacks; my understanding is that it was the cooling pipes that glowed red, and it was this 'hot metal' and not the flame which was visible from a distance - especially relevant in night fighting.

Mr. Maddox, a quick question on last weeks update; Was the map in the FMB a temporary version, or does the SoW map have structures from after the war? (Like the Basin de L'Atlantique at Gravelines, WSW of Dunkerque?)

Bear in mind that the Luftwaffe used effective flame dampeners. After extensive training in identifying flame patterns an American pilot said he never saw flames due to the dampeners but the training did help him separate Luftwaffe flights from Allied.

S!

I doubt they would run up the DB engine above idle as the manual for it states you have to wait until oil/fuel pressure exceed a certain limit. The idle RPM for DB605A-1 is 600-700rpm and in the video the RPM was not high IMO. But good points BadAim. Anyway in above videos can be clearly seen blue flames instead of yellow. I would bet the yellow would come if the mixture was way too rich or unburned fuel in the cylinders when firing up. Well, let's see..Also note that the blue flame did not light up the plane as much as in SoW video.

Please read with atention: The color of exhaust from the direct pipe and from the extended are different. The temperatue of the flame decreasing with the longer leght of pipe. More lower temperature - more red flame. The most hight is right from the hole without pipe.

As I told above a lot of factors is present in forming of color.

They're all pretty much the same. Big row of cylinders igniting avgas in them and venting the exhaust out the pipes in the side. Unless there was some sort of addidive that would change the colour (not likely) then they'd all be blue like you're suggesting.

The flashes are one reason why some 109's had the exhaust shield covering the pipes, so they would not be seen in low-light conditions, but as oleg just mentioned there are other factors at work.

.

S!

If comparing Spitfire Mk.I/Hurricane early marks and Bf109E-4 it can be easily seen that the Spitfire/Hurricane have longer exhaust pipes than Messerschmitt. I recall reading the exhausts on a DB engine were very short, in range of 10-15cm only.

I already corrected myself after Oleg's post.

Final size. No changes. We can't satisfy everything. There are limits in size by memory, limits of other type, etc. We was need to cut by this way. Originally plannen way more greater. But there is a great contradicitons between what to put in terms of detailization and what would be the size due to this detalization. Again it is impossible to make everything withouit going for compromisses.
In Il-2 in every map we had also compromisses. Repeat: in every, is it crimea or moscow map, etc. And we were need to cut other possible historical action as well due to this fact .

Lovely update. Love the individual cylinder firing. Shame early Spits have cylinder exhausts in pairs, I love to see them firing in proper firing order accompanied with the exhaust flames, faster and faster as RPM grow. Out of all all in-line engines, nothing beats the magnificent, almost perfectly balanced V12. :)

As for the flames, I too would like to see them more 'on the blue side'. However, as you have said it all depends on the fuel quality, which is nowhere near when compared with what we have nowadays. Definitely a mix of yellow/orange and blue burnout...

It was already in IL2, so should be the same in SOW.

Try taking a late war 109 for a spin and see how fast it runs out of the good stuff (30mm hub cannon). The only planes that seem to have "Hollywood" levels of ammo are the larger American fighters like the Corsair, and P-47. If you opt for the P-47 with extra ammo you can hold down the trigger the entire length of your mission and still land with enough lead in the guns to down a bomber.

I imagine that Oleg and Co. have figured out the exact historical loadout for all the fighters involved and you won't be given an extra round.

Just by dealing with exhaustion effect - during night - time, means only 1 thing ...

the new title has gone onto another level all together and that is apreciated by all

IL2 fanatic customers.

Oleg,

but if currently cities and towns on the BoB map are moddeled to large (compared to 1940's maps), are we not wasting fpsec on having our pc's draw and display houses/buildings which are not needed ?

see the end of last weeks thread for discussion on this, and historical maps of town sizes posted (in comparison to what was seen on the recent BoB preview maps)

note: this is intended as constructive input, not a "complaint"

S!

Quickly read some things and found this explaining the flame color quite simply and well: "The flame colour of stoichiometric burning is described as a "bunsen blue", turning to yellow if the mixture is rich and whitish-blue if too lean." I hope this helps.

I think that's a qualified assessment and I'm inclined to agree.

Hi Oleg, JAMF's question was I believe purely relating to geographical features visible on the mini-map that were not in existence in 1940 (or, indeed, until after the war).

In other words: content accuracy, not map size (also regarding the extent of some cities and towns in 1940).

Great video update, thankyou!

Incidentally I'm also in the "blue" flame camp. I acknowledge the aircraft I see at Duxford are using top-quality fuel that may not have been around in 1940, but I do recall pilot accounts in various books I've read describing blue flames from Merlin engines at night.

Cheers!

Spinner

Very nice Oleg. I know it's not to do with engine start, but looking at the first video, I wonder of the red gun port tape will change once the guns are fired? Small detail, but was just wondering.

PPanPan

Oleg,

JAMF is not referring to the size of the map (and, for example, no Duxford).

He is writing about some cities being larger than they were in 1940 and the map including POST-1940 structures. Dunkirk's Bassin de l'Atlantique, which is on the SoW:BoB map but wasn't built until after the war, for example.

C_G

I think the flames look great, going by those videos posted and seeing other engines at night in person I would have to agree more blue and red flames...but again I trust Oleg and his research on the different fuels and factors that I have no idea about.

My main concern is the flame reflections. In all the real videos posted you don't see any reflections of the flames on the aircraft. Where in the night video posted by Oleg it almost looks like a police car light reflecting off the aircraft.

Make the flames more red and blue, reduce reflections and I think we have a winner. Great update thanks! :grin:

Flying at night is going to be awesome in BoB!

Definitely less yellow or red, the fire should be a blue colour Oleg. This is caused because the exhaust outlets are for the gases made when the fuel is burn and that gas burns blue.
I loved the way when the spitfire started, it wasn't just one burst of flame. I love the modelling system you have for engine starts. Well done Oleg and team!

Rich mixes, air to fuel, helps older engines with lubrication also but you'd have to clean out ports and valves more often because of the excess carbon

Yes, the tape tears when the guns are fired.

Hi Oleg

You have the flame colour about right for initial start up but probably to fast in engine speed, slower start to run up.

I've seen a few of these engines start up :)

1. Lazy/slow red/yellow flame from fuel primed start up.

2. Blue smoke clearing cylinders with yellow flames to brown/grey smoke.

3. Blue with yellow tips on engine run up and under run.

4. Shut down black/grey exhaust smoke short burst.

If I can find some of my video will e-mail it.

What I like each time an update is posted is the army of volunteer Art directors and armchair historians/aviators that come in adding their salt to the soup.

This time it's exhaust flame color. Last time it was about map size. I'd be curious to see how many folks asking for changes or complaining ever worked on a game. How many of those folks are ready to upgrade their rigs to get a decent FPS.

Seriously there is a diffrence between asking questions and demanding changes on an unfinished product. It's already good that those little things are in there. It could just be a non lighted reddish texture mapped in the exhaust and have it called an exhaust glow but there are lights actually lighting up the engine cowling and particles, that's good.

Anyway keep up the good work, thanks for the updates, they make my day.

BTW are you alpha or you're beta?

I just clocked it(UP2.01 MkI).

1st: You're right
2nd: I am an Idiot, should have done that before.
3rd: deleted my post - to save space and the original is quoted anyway.

Sorry.

Duxford 2009 (the size of the pictures is reduced)

Awesome videos! Thanks for posting. I really like the way the propellor has been animated in BoB (it shows how the human eye would see it in real life - for added immersion :)). My question (more of a suggestion, really) is for those of us who wish to create screenshots with a period feel (where the prop blades are visible as dark bands around the propellor hub due to shutter speeds/refresh rates??). Would it be possible, perhaps in a future update of BoB to have propellor effects toggleable so that the default would be the realistic effect you have now in game but that an IL-2-style propellor effect could be selectable for the purposes of period screenshooting?

Just a thought,

Fafnir_6

DUDE, Oleg specifically asked for input on the exhaust flames!

No-one has been whining that they're not good enough. The posts on flame colour have all been constructive and backed-up their opinions with something.

Clearly this is something that Oleg is still tweaking.

He's made it clear that the map SIZE is set and not open to debate, but I don't see anyone whining about that. Some of us would like to know, however, if the map objects are still open to revision. Also not whining just a query.

C_G

Hi

Please read Olegs first post in this Friday update.

He's asking for advice from those that have seen these things in real life.


Woops well done C G you beat me to it :)

hehe..actually I am an art director ;-) but never mind, it's not about that.

That amount of flame from the stacks at start up points to one thing, and one thing only, the engine was grossly over primed before start up.

I have seen dozens upon dozens of Merlins, Allisons, Wasps, Cyclones, and a DB 601 start, all in day time, and never once have seen that much flame come out of the stacks. Smoke certainly, and lots of it on some engines, but never large curling flames like that. Operator error, pure and simple.

Not bad, but the flames are still too "yellowish" like in IL-2.

its sad to hear a spitfire with sounds of BF109 in IL2-1946

Its sad to hear some one say there is a DB601/5 engine sound in il2 :lol:

You've got to know that those sounds are no way the final sounds LOL

Here's a nice night vid with blue flames. Don't know the details of mixture setting, but for such a high RPM run-up we might suppose it was rather on the rich side. On the other hand, no short stacks here, so direct comparison is not possible...

http://www.youtube.com/watch?v=wMPdV6xA8X0

Cheers

He also explained why blue exaust in most instances is incorrect yet most here want it to be blue?

Maby the refferance in books saying the colour is blue is because they saw the flames in an angle looking straight down the stacks so to speak (from an angle and from behind) , like oleg explained, flames are blue just at the beginning of the outlet and gets more yellow the longer the stacks are.

just guessing.

Very interesting video! It is interesting to see how at high RPM the flames are definitely blue, even with long pipes, but when each flame appears could it be that for this short time the exhaust pipe itself goes cherry-red/yellow? This would maybe explain what one sees...

JV

One question about the last topic :
Will the ground vehicule could be weathered like the planes (maybe in a futur part) or not ?

Great work also :-)

the light radiating from the flame is too yellow no matter what the color of the flame, too much saturation

Flame colour has nothing to do with the angle you view it from or the length of the exhaust pipe, it is nothing to do with temperature either. It simply shows how efficiently the fuel is burning.

If the combustion is burning all the carbon you get blue flames and no smoke. If there's carbon coming out in the exhaust gases then you'll get yellow-er/smoky-er flame.

This is chemistry not opinion.

Hawker Sea Furry?

Seeing all the vids of merlins and DBs I'd say blueish like many before me.
The color of flames indicate temperature and as temperature increases flames turn more transparent (the hottest temperatures are nearly invisible as I remember from chemistry class) but hey, I'm not an expert at that
I think the flames should be more transparent (in case when you'd use blueish flames). They also should illuminate the fuselage just slightly... just my opinion as a draughtsman, from what I've seen in the vids posted.

Anyway, nice feature...

Edit: maybe winny is right about that, efficiency rather than temperature but still

Actually, Winny is right, it doesn't depend on those factors.
Color is related to the temperature of gases produced during combustion: the hotter, the whiter; the colder, the redder. Blue indicates a very high temperature. Near-perfect combustion of hydrocarbons is always blue.

Yellow indicates an imperfect combustion, i.e. lack of combustive agent (usually air) which causes production of soot, i.e. smoke. However, even a very rich mixture as used on a cold engine would not produce yellow flames, but add a yellowish hue at the end of blue flames.

Red indicates a very bad combustion. A damaged engine burning oil would probably produce reddish flames.

Hope this helps ;)

Fantastic job !!!

Is anyone familiar with the colour produced when the 'Ki gas' primer is used with full rich mixture, 100 octane fuel and a cold engine?

These are the only factors I can think of which might together produce a yellow flame, other than unburnt fuel igniting against hot exhaust stubs, which from video evidence already posted is more orange.

Otherwise, I'm a little confused as to why our opinions were invited. All evidences posted point to blue flames and yet we're told we're wrong.


'Confused' of Milton Keynes

The sound of the plane is the same as in il-2. Is it just temporary or final?

I'm probably being a little pedantic, sorry :)

Temperature is related to efficiency of burning too, so it is linked to the flame colour, but as they are both effects and have the same cause I ignored it..

You could get yellower flames from an exhaust pipe that had a build up of soot inside or around the edges of the pipe, but this would eventually burn away.. maybe they start yellower because the pipes are dirty?

I know that when they were testing the Spitfire at Boscombe Downs for night flights it was recorded that the exhaust flames were blue.

I was going to say something to this effect in harsher words but decided against it

these people seem to make sense

Welcome Changai.

Thanks for your first post here, and I can say that you are Spot On !

Following the A.P. 1565 A (Spitfire I, Merlin II or III engine) 'STARTING THE ENGINE AND WARMING' procedure, the mixture should be in Full Rich with a 1/2 inch open Throttle , not quite a blue near-perfect combustion situation. ;)

On this 'September Fury' dusk video, the blue flames panache appears only at a continuous high power regime.
Note the absence of blue light reflection on the 'Fury' fuselage.


and by the way, thanks for the Update. ; )


...

Yes, it's the 'Ki gas' primer I don't know about.:)

Exactly. In general, hot=blue, cool=red/yellow, plus a flame that's seen directly exiting the piston will be hotter than a flame seen after travelling the entire length of the exhaust pipe.

So, since the colour is a function of exhaust gas temperature, i guess that running on higher power will produce bluer flames. Also, leaning the mixture at night could be done by watching the flames, you just have to lean until the highest exhaust gas temp which means the bluest flame you can get, then enrich it again just a tad from that point.

I might know how the stuff generally works but it don't know what the correct colour for each circumstance is. However, i'm really excited about these features because they give the impression of a real, working machine under the hood. Excellent update!

:grin:


...and the way pilots of prop driven aircraft adjust their mixture today is by, guess what, a temperature gauge that monitors how hot the exhaust gas is. So you're correct generally, except the part where you say it has nothing to do with temperature. This is also not opinion but physics, whatever burns hotter is to the blue/white side of the spectrum and stuff that burns cooler is to the red/yellow side. It's the reason even the stars are not all the same colour. Cheers ;)


Edit: I just saw you corrected it yourself :grin:

So, now I've thought about it.. anytime the engine is running efficiently we should see blue-er flames in SoW.

The less efficiently the engine runs the yellow-er the flame.

That would beg the question, what effects an Aero engines effectivness at burning fuel?

Rubbish fuel?
Altitude?
Damage?
Mixture?

I put question marks because when it comes to engines I find them exactly like women.. I love them, but I dont understand how they work...

Great videos Trumper. I've put together a few stills from the Just Jane night runup you posted.

When running fast the flames were short and a dull red in colour.
When reduced to an idle the flames were longer and blue in colour.

The red flames flickered but were visible at all times from all exhausts.
The blue flames were intermittent - just ejected every now and then.

None of the flames were bright enough to illuminate the cowlings of the aircraft. This is my experience from a couple of merlin night runs I've witnessed. The only time the aircraft is lit up is when the engine has been overprimed and the full fuel flames are seen pouring out for a few seconds on initial start.

This makes sense since an aircraft lit up to the extent we see in the SoW video would have made a perfect target at night. I know the brightness of the exhausts was a problem at night for pilot vision - in First Light I remember reading that Geoff Wellum couldn't see the runway lights below him at night because strips of metal were attached to the fuselage of his Spit to hide the exhaust outlets from the pilot, partially obscuring his downward vision - he hadn't realised that and thought the runway lights were being switched off every time he flew approach!

Unfortunately, the stills I've captured from the Just Jane Lancaster nighttime runup show exactly the opposite Blackdog......when RPM is high we see short red flames. When idling the long blue flames are ejected intermittently. Could be that this old Lanc just isn't tuned up properly like a flyer would be.

Dunno!

EDIT: Sorry, it was someone else who related colour to engine speed. I agree it is temperature based like you say and the temperature at any RPM will be dependent on the efficiency of the burn...mixture, cold/warm engine, degree of wear in the barrels etc.

Did you read Oleg's first post? :rolleyes:

Engine runs with an external program... to me it sounds like your utilizing the a2a`s accusim

is this the case?

Try this Oleg

http://www.rogerdarlington.co.uk/Hurricane.html

"Even with the flame shields over the exhaust, I found the flickering blue flames strangely comforting over the water but, once over the French coast, one felt very conspicuous in the night sky". His squadron colleague Morrie Smith makes the same point: "I felt that everyone for miles around could see the exhaust stubs glowing in the night, but the anti-glare cowlings protected the pilot's night vision from this glow".

"As I descended deeper into the cloud, I experienced a frightening phenomenon: the whole inside of the cockpit was lit up by a red glow. My immediate reaction was: 'Fire!' But there was no heat and all my instruments showed everything to be in order, so I ventured to look outside. My two exhaust manifolds were belching out the usual flame, made perhaps a trifle more red and less blue from being throttled back, and this source had illuminated the surrounding very dense cloud. It was an eerie sensation but, once I knew what it was all about, it ceased to trouble me".

Don't forget the glowing stubs :)

Well, I've spent most of my life dealing with engines for a hobby, whether model aircraft, motorcycles or cars. I've also been an aircraft nut since I could walk , and I've never seen a yellow exhaust flame like that shown except from a damaged engine, or one with which I've had to fill the air filter with 'eezy-start' to get it running (which usually meant it was damaged anyway). Even then, the yellow flame soon clears unless the motor is really coked up or has badly pitted valve seats/bent valve stems. Even then the effect wouldn't be uniform for all cylinders. Most primers I've come across are methanol based, which also burns blue/violet.

Hence my question about the primer used. If the yellow flame is indicative of the primer, fair enough. If not, the flame should be blue.

(Actually, I just watched Rudolph's video post again, and the bloke is obviously hand pumping the primer, and, oh look, the flame is still blue!!)

The argument about altitude and RPM is also unfounded as the aircraft was on the ground and ticking over, as were the videos posted.

Like Blackdog, I'm also an amateur astronomer and yes red giants are cool and blue giants are hot. White Dwarfs are very hot and quite nasty, but the exhaust flame of a spit at night should be blue.:)

The MkI, II and IV spits had covers over each pair of exhaust stubs which purportedly produced a degree of 'boost'. It's possible that soot could build up in these somehow and burn to produce a yellow flame, but the ground crew should have been put on jankers for poor maintenance.

I'm beginning to think Mr Maddox does this deliberately just to keep us occupied.:grin:

The thought has struck me too :)

...


Around 08'00" , note the many glowing burnt fragments in the prop wash of this mighty Lanc confirming the bad combustion (dull red) of that transitionnal and intermediate engine power.

http://www.youtube.com/watch?v=k9AGb...ayer_embedded#!

...

Thanks for the up-date, the grass moving looks cool:grin:

Apparently a merlin 45,I don't see any flames:

http://www.youtube.com/watch?v=cv0Onh6NzPA

And another one:

http://www.youtube.com/watch?v=wIpgk-1OfFU

I often feel like that when I'm at work! ;)

I realy like the way the spitfires suspension reacts in the first video. That little dip of the wing as as the plane turns and comes to a halt. It really gives the impression of inertia and the mass of the aircraft.

Cheers and thanks for the update!

Well spotted Rodolphe, I skipped that video for some reason. I notice the same red flames as in the other clip but they appear clearer and longer since there was no external lighting this time. I agree that the engines are probably poorly set up in this case. So...blue flames when running efficiently and redder when the mixture is made richer.

I still see no reflections on the cowlings.

I've taken a few more stills to illustrate in the attached piccy.

That depends on how it's started. These are not typical, but show flames can occur:

http://www.spitfirespares.com/spitfi...h%20flames.jpg

http://www3.pictures.gi.zimbio.com/E...9_syXG3asl.jpg

I think the start-up video is ok. If I had one qualm with it, it is that the smoke of that quantity dissipates very quickly. Either the smoke should be much less, or it should hang around longer if it's going to be that big.

Here's an example, but every video shows the same thing:

http://www.youtube.com/watch?v=FzsJBjbCyvM

3:05

Regarding exhaust flame at night - I will leave color to the experts. I would like to point out that color doesn't always have to do with temperature. Some flames burn green for instance, or purple. I would also like to say that the ambient light from the exhaust seems too strong. While exhaust flames would have been an important factor in finding your enemy at night, I don't think they would paint the side of an airplane bright yellow (or any color for that matter). The same occurs in IL-2 when firing guns (bright yellow glow on side of plane and in cockpit), which I think is not accurate.

Regarding sounds - even in IL-2 they are good, but one that was missed was speed of sound in air. Explosions a mile away are heard instantly. I hope this feature will be implemented in SoW. Secondly, sounds are modified by air flow. If it's a windy or turbulent day, the drone of an engine is going to fade in and out in a random way, with the degree of rise and fall of volume increasing with distance. Thirdly, low frequencies travel farther than high frequencies. So, when listening to an engine that produces an array of frequencies, you will hear a low drone when it is far, and a higher click-clack buzzing when it is near. I can't decide if this is modeled in IL-2 or not, but I'm throwing it up here anyway.

Those Merlins have those fancy covers over the six stacks though. You can't really see if it's flaming or not. Come to think of it maybe that's why they're on there.

present color would be OK for a cold engine rich fuel startup. does the color change as engine warms and mixture is leaned?
blue with a pointed white center is optimum