Hello all,

I have Il-2 1946 and its brilliant, but one minor gripe (it really is minor, i'm just very pedantic) is that the jets have flames coming out of the exhausts. Unless i'm completely mistaken, this is very inaccurate. Is there a way of turning this off without affecting the rocket powered aircraft?

- Alex

Yeah, that's one of the things that I find annoying also!
Those jets look like they're on fire, not realistic at all!
Hope someone will make a little mod for removing the flaming exhaust.

Best regards, Kodiak.

Here is something else...

just got out of the 4.09 Jets server at Hyperlobby and it seems the jets are a lot tougher. I hit two different types of jets several times and failed to down either one.

It used to be that any hit on a jet would bring it down...yet I do not see any change in the 4.09 readme for the jets.

Actually, I find the look realistic. Those jets worked different than modern turbine engines, and produce a far different flame.

From what I've read, the guys who flew & fought in WWII & Korea said the jets were harder to shoot down that prop jobs. They took more hits & they thought it was that there was less 'plumbing' in jets than props. The plumbing is my take, not their word.
Yes, there's very little in comparison to those early flame throwers, as what they were called, till now. They consumed lots of fuel with poor efficiency thus more fire.

FWIW,
Good Hunting!

It may not be that inaccurate. http://www.youtube.com/watch?v=CAsGmHjdlTA sure this is just a startup but if flames can pass thrugh the turbine then it may during high power settings.

Not really an accurate comparison as those engines are not what the wartime 262s had. What we see here, as you mentioned, was startup, but are also modern types. Just watching early jets take off with all their smoke & fire compared to todays makes for quite a difference. Seeng film clips of those early B52s or even early passenger jet planes & the ones now with more modern engines, is quite remarkable. Not near der smoke und fire.

FWIW,
Good Hunting!

I'm pretty sure it is unrealistic as you only get the flame when there's a second injection of fuel after the turbine (as far as I know).

At the very least, there shouldn't be smoke AND a flame, as the flame is caused by the unused fuel being ignited (why aircraft with afterburners on don't produce smoke).

While i've never seen a '262 fly i've seen several other early jets in flight (including a T-33 which is closely related to the P-80) and it certainly didn't have that exhaust effect.

Same with meteors, vampires, venoms etc.

It's all in the throttle settings. Even mit pistons.
FWIW,
Good Hunting!

Being a jet engine mechanic I can tell you that afterburner works with fuel being supplied after the turbine section. This is to make use of the cooling air which is most of the air taken in by the compressor. Fuel to the afterburner spray bars is only supplied when the power controls are set in afterburner. Since this cooling air passes through the lining of the combustion can all fuel from the main fuel nozzles will be burned, it just depends on how far it needs to go before it does. It is possible to have flames pass from the combustion section through the turbine section and out the exhaust although it is not the norm. Considering that was new technology at the time I can see the engines working like this since poor design in the combustion can, Venturi, and fuel nozzles would cause extended fuel burning.

The smoke produced unless white is not fuel. The F-4 had afterburner and produced black smoke although not as dark as shown in the game. Also jet fuel has changed over the years and if the p-80 used jp-4 back then it is most likely using jet-a now with is the equivalent of jp-8 for the military which could change the efficiency of burning which would mean less carbon in the exaust.

The fact that I saw flames come from the exhaust from that video makes me think that it was possible and black smoke is a little overdone in my opinion but I have seen it on real aircraft.

Good points there SE. Fuel quality & quantity can make a big difference in quality of burn. Overly rich due to too large a quanity or poor burn because of too poor a quality, can make for an overabundance of smoke & fire. I'm still in awe when I remember seeing my first & only B52 take off in the 70s. I couldn't see much fire but sure lots of smoke.
Fuel octane was always a problem with the Germans in WWII. Whilst the Allies enjoyed close to 100, the Huns were about 80, not much different than our low grade pump gas today. The DB engines when under full throttle smoked so bad that Allied pilots thought they were damaged so gave up the chase. All the Hun was doing was extending to safe distance & then come back under more favourable conditions.
Anyways, thanks for all the input & I have been known to be wrong sometimes so maybe an education is in store for me, AGAIN!

FWIW,
Good Hunting!

I used to spend a lot of time at RAF Binbrook in the late 70's and had the pleasure of watching the English Electric Lightings spool up and take off. Very little fire except for a blue plume at the initial "fire" then just a heat ripple and hot red close to the exaust. I recall one throwing a turbine blade and the addition of a spark shower made a pretty sight but that was the exception rather than the rule!

That was one of the sweetest aircraft I have ever been around, I miss them dearly.

Ogs.

I'm really glad I started this thread - its turning quite interesting! Thanks for all the factoids guys!

Cool experience Ogdens..

I spent some time around F-4E's at Hahn AB in the late seventies. I remember the black smoke emissions quite well and the noise could be unnerving too. They'd take off in pairs at night sometimes.

The Illinois National Guard used F-4's in the 70's.
I lived close to the airport and we would go watch them takeoff on the weekends.
They always took off in pairs.


Wheels

Random quote from the internets... so it MUST be true!



But that cock and bull about the smoking Hun was funny too

Be nice Hauschild, it doesn't cost any more.
German Fuels
A3-80 Octane
B4-87 Octane
C3-100 Octane

Due to a shortage of C3, DB went to concave pistons to lower the compression so it's engine could run on the lower octane numbers. This limited preignition & detonation within the cylinders on the compression stroke. Even our higher output engines of today with computer controlled timing & fuel mix don't do well on our 87 low grade fuels. I'm not talking about plain jane engines, which most are, but the higher output ones. Because of their higher compression ratios, they smoke & make noises under heavy acceleration. That's why I believed in what I've read about the DBs doing the same thing. The first time I read about this smoke was in James F. Craig's book, The Messerschmitt BF 109. I think he called it a 'sooty black exhaust'. Since then I've read it quit a few times & with my auto repair experience, I did & still believe it.
The bottom line is, overly rich running internal combustion engines give off black smoke. The computers on the vehicles of today, making auto adjustment, stop most of the noise & smoke. In the engines of old, under heavy acceleration, went rich & smoked. With carbs one rplaces jets for mixture whilst with injection, it's an adjutment. Jet or adjust for leaner or richer, altitude being a factor. An air/fuel mixture @ sealevel would not be suficient @ a higher altitude. A clean burn @ the lower would be a richer burn @ the higher. That's why the carb ones would keep adjusting their mixtures for inches of mercury so a more efficent burn would take place. I don't know wether the injection DBs had this abilty. Methinks it was adjusted on the ground, for whatever job was in store, ground attack or bomber busting etc.
Anyways, I've gone long enough. I've found that trying to change attitudes is hopless & it quickly goes into a who's right or wrong rather than what's right or wrong.
Thanks for all the input!

FWIW,
Good Hunting!

These engines didn't have an afterburner.

IIRC correctly, Iowa ANG was still using F-100's in the mid 70's. They'd fly'em into the airshow at Offut AFB.

DB601
Compression ratio: 6.9:1

DB605
Compression ratio: 7.5/7.3:1 with 87-octane fuel; 8.5/8.3:1 with 100-octane fuel

DB603
Compression ratio: 7.5:1 left block, 7.3:1 right block

Merlins had a 6:1 CR and the Allisons were slightly above 6:1.

Don't see no lowering of CRs.

Late war C3 fuel was pushing 140PN.

Since this started, I've been doing some online checks & there is so much more than my books or what I've heard said over the years, & a lot of it contradictory. Late war fuel production was bad, & the supply of isoparaffin so short, that to get even 100 octane was a stretch. Some say it was closer to 95, German numbers. The Allied numbers were about 130 to the German's 100. Just a different way of figuring it out. Methinks low to high alt was in there someplace. Think about it, around the clock bombing on roads, rails, & industry. There were no luxuries afforded to fuel for trucks, fuel for tanks, fuel for different aircraft, etc. On some air bases, from what I've read, there were differnt fuel tanks for the different planes & one better get the right fuel for the the proper application or all Hades would break out. There was always a shortage so the lowering of the CRs for all AC was beneficial to all concerned.
Now to the concave pistons, for an example, Chev had an engine called a 327 & this egine, over its' life span, was put in family cars, corvettes, & trucks. HP ratings from 210,225,250,275,300,325,350,& 375, all from the factory, all from the same basic engine. The pistons were either concave, for some trucks, flat tops for your family cars, & dome tops for the muscle ones. The concave gave more cylinder volume for better volumetric effiency, but also lower CR which adversely affected HP output. Also, a lower grade of fuel could be used as compared to the muscle cars. Now when I read about the Concave Pistons in later DB engines, I naturally assumed that the process was the same. Unless they increased the piston stroke, I still stand behind the concave theory. Domes for more, concave for less. The one other thing they might of done, was change the cylinder head dimensions, thus the squish band. Now this could increase Compression Ratios.
I've got an tape of actual footage of 262s taking off & there is black smoke. I'm going to try & find it & play it again & see what else is on it. Stay tuned.

FWIW,
Good Hunting!

PS. I hope I don't sound like I'm turning this posting into a who's right or wrong rather than a what's right or wrong. Me trying to sound the more intellegent to boost my ego by faulting the other person is just plain BS. I've been known to do it all so really trying not to do so.

USSBS


Strategic Air Attack on the German Chemical Industry
http://www.angelfire.com/super/ussbs/ussbsappa.html#lead

The relative volumes of production of the two grades cannot be accurately given, but in the last war years the major volume, perhaps two-thirds (2/3) of this total has the C-3 grade. Every effort was being made toward the end of the war to increase isoparaffin production so that C-3 volume could be increased for fighter plane use. The isoparaffin usage in that grade had already been cut to a minimum

http://www.fischer-tropsch.org/primary_d...0Specifications

Man, I really screwed up here. From too much fire/smoke to fuel production was quite a leap & I guess I started it. Me bad!
What was being produced & what was reaching the fighting & training units are two different stories. Books Iv'e read, written by first hand pilots, have said that the fuel quantities were low & that new recruits coming in had very little flying time because of this shortage of fuel. Production is moot if it's not reaching the consumer. Sometimes only a few planes got into the air & the others stayed on the ground with empty tanks. Also, because of a real shortage of higher octane fuel, the engines were being modified to burn the more common lower octane fuels @ the front lines. Shipping one is much simpler than shipping multies & more of a chance of getting enough to the front lines.
Anyways, over the years, even before I came on here, there was always discussions of German fuel quantity & quality. The ones who opt for the quantity/quality think that's why Germany lost the war & the other camp rigorously refuted that. The graphs would come out & in a lot of case, some graphs contradicted each other. Who knows what is true in graph land but I still believe more of the ones who were there, not so much the history books.
The fuel problem, quantity & quality, sure curtailed the German war machine & I THANK THE GODS FOR THAT!!!!!!!!!!!

FWIW,
Good Hunting!

Kraut, you do know that the Fw190 with the BMW801 engine required C3 fuel.

No, I didn't know that. I do remember reading someplace where the later 190 radials had spark plug problems & it was fuel related. Now if this was an isolated incidence or not I don't know. I do know that low octane/quality fuel can cause preignition & detonation which plays havoc on plugs so I assumed this was the problem here. What was required & what was available are two different things & the articles I read from the pilots themselves also could be isolated incidences. I've run a tank of Esso summer fuel that's had been sitting for a while, in mid winter, I had a tendancy to blame Esso Oils. One time & I'm quick to blame.
I've been an engine nut for over 55 years starting with my parents lawnmower so this stuff interests me. I had a ball in the 60s with muscle cars & now just focus on Harley Davidson bikes. Just going to do a top end overhaul on my new toy, an 84 Evo engine. To think, these V Twins from are a spin off of a 7 cyl. radial AC engine.
Anyways, KraziKanuk, thanks for all your info. It sure has broadened my knowledge base & even @ my age, I can still learn more about things that I thought I knew.
I think I use to call you KK a few years ago. I asked about the AC War Museum in Ottawa & the wife & I rode down & saw it out @ the airport. Great ride, great country, & a must see Museum.

FWIW,
Good Hunting!

German fuels had more aromatic content than Allied fuels. This is why the British test of the Fw190A had engine problems.

Data sheets on some DB engines
http://www.fischer-tropsch.org/Tom%20Reels/Linked/A5464/A5464-0638-0654%20Item%206A.pdf

Next time you are up here, visit the Gateneau airport.
http://www.vintagewings.ca/page?s=63&lang=en-CA

Great stuff there. I especially like the address you gave about the Gateneau Airport. There's some great reads on that site, most info being completly new to me. I don't know how many books & mags I've read over the years about WWII AC, but lots. Reading autobiographies from pilots gave me some moments. Like the plane they flew was the best when the 'books/charts' said otherwise. Just reading from that above site about the 109 flight contradicts what other pilots have said. Even that British test pilot who flew one was more in favour. Hades, I've read where Charles Linberg & Major Al Williams gave rave reviews after flying a 109 in 1938. Lindbergs quotes, "The plane hsndled beautifully". "The 109 takes off and lands as easily as it flies". Those statements are not we read & see today but the 109 pilots loved them, the ones who survived the early days of flying them. Now back to fuels, who in hades knows due to the different charts & statements. My guess, nobody. Just look @ the charts for flying, fighting, speeds, ROCs, etc., etc. & they're all over the board. Pilot Notes are more accurate but even then, some contradictions come out. I base my stuff on my 45+ years of repairing cars & light trucks & I'm not saying it's all right. The rules that apply to car/truck engines also apply to aero engines. An internal combustion engine is an internal combustion engine no matter what vehicle its in. Compression, fuel, spark @ the right time, & an expulsion of the exhaust gases is all that's needed. Altitude is what really sets aero engines apart in the fuel dept. Rich makes black smoke & overheats the exhaust system. Poor fuel or incorrect timing makes for knocking thus holes in pistons. Too low an octane does the same thing & in either case, poor performance.
FWIW,
Good Hunting!

Just two of the books I read were
Messerschmitt BF109 at War by Armand van Ishoven &
The Messerschmitt BF109 by James F. Craig

Linberg and Williams flew early models of the 109, much lighter a/c with a lower HP motor. The 109C weighed 5,062 lb while the 109E-3 weighed 5,062 lb, the 109F weighed 6,054 lb, the 109G-6 weighed 6,940 lbs and the 109K-4 weighed 7,400lb.

On late war lower CRs, the DB605D powered the 109G-10 and K-4.

Sorry posted the wrong link in a previous thread. Should be
http://mitglied.lycos.de/luftwaffe1/aircraft/lw/DB605_varianten.pdf

As can be seen, the CR was 1:8.5/8.3. The G-10 and K-4 were the major production models, late war. This engine could run on B4, B4 + MW50, C3 and C3 + MW50. From what I have read, it only took the use of a screw-driver when switching fuels.

The DB engines did not have removable heads like on the auto engines you mentioned Kraut. (are you familiar with the old Hurricane outboards from Mercury?) To change CRs the piston crown had to be changed.

I knew they were early models with just the rifle cal. MGs on board, but they were having problems even then. With the E line it even got worse and really bad, as you mentioned, as the weights & HP increased. The torque would be large on those landing gears & on an approach, sudden throttle changes were to be avoided if at all possible. I have numbers someplace on the problems with the first 109s even before opperational status. So when I read about those two gentlemen & thier experience, it just muddied the water, again. Williams did complain about the outward retracting LG & was assured by Udet that it would be changed to to fold inward. On a side note, a 109 engine in 18 could be changed and the AC ready to go in under 12 minutes. A standard USA engine between 24 & 36 hrs.
There's a faint recollectionf the cyl. heads but so faint as for me not to believe it. To bore & hone out an engine block from one end is really foreign to me & sounds so , well so weird, totally. If they put concave pistons in without legthening the stroke or doing work on the squish area, the CR would be less & they could burn a less octane fuel.They started with B4(87Octane) & then in 44 went to C3(100) & then back to B4 & MW50.
I've never worked on a boat engine except help change a plug & even then I wasen't in command of the tools. I've saeen model AC engines with that arrangement but I find it hard to bring my head around the same process for big cube engines.

Oops, gotta go & again thanks for your info. ya got my gears agoing!

FWIW,
Good Hunting!

Actually Kraut C3 was available during BoB and used by a 109 Gruppe and the 110.

One thing to think about is if the they thought the 109 was a sweet flying a/c, what does that say about American a/c.

On the engine change times, there is a lot not mentioned. example: Was the a/c already striped of prop and cowl panels? Were the oil and coolant lines already disconnected?

To attach the lift chain, remove the engine mounting bolts, lift the engine out and then reverse the procedure, it might be possible in 6-9 minutes but the a/c is surely not ready for flight.

Hi KK!
Well, I'm back. Civic duties can sometimes really cramp my style but somebody has to do some.
Now, where were we? oh yes, the cylinder heads. Nope, on some 2 strokes with no valves & thus valve seats but never on a 4 stroke. It just behoves me how they would install & grind valve seats from the bottom end. I know the huns could get real complicated but this is a mind bend. I've worked on Audi & VW for the past 7 years & talk about overkill. None of my books show about the headless DBs so I went OL but still nothing. Differences in CRs from bank to bank was another surprise to me. I'm starting to think I know next to nothing about these crates. They fly in the face of conventional wisdom, IMO.

Darn, another call & another all nighter.

FWIW,
Good Hunting!

check out this link Kraut, http://allaircraftarcade.com/forum/viewtopic.php?t=17837&sid=140b2a9f8839369880b71ef042f0bf4b

Notice the valves look to be vertical.

It's me again KK!
Thanks for the pics. How do you find all these gems?
Now I 'think' I can see how it's done. The cyclinder is short so when it's unbolted from the crankcase, the distance from the cyl. base to the where the valve seats are, is not all that long. Overhead valves inserted from the bottom & then locked in from the top as per conventional ways. But, the machining for a wartime piece of equipment, ala like their tank engines, makes little sense. All that for how long a life expectancy in combat?
This screww adjustment you mentioned above reminds me of an adjustment for enrichening or leaning fuel injection on early diesel engines.
When an aero engine from that area was on put onto WEP, a rich condition was in place. In fact, that one 109 take off above clearly shows the DB smoke trail when on T.O. Power. If it smokes that much @ low alts, it must of really smoked @ the higher ups. As I mentioned above, some pilots said & wrote, they thought it was damaged & heading out of the fight. Also, the Allied pilots knew which runway was used by the 262s by the scorch marks from their engines on take off. Those scorch marks I bet were from heat & carbon, ie. fire und smoke.
As far as the Octane for when & where is still all over the boards. I learned back in my discussions/arguments in Air Warrior & Warbird days that to read one set of 'facts' may & do, some times contradict another set of 'facts'.
Through all this, I have learned a lot about the DB engines & I thank you for that. I'd really like to touch one, & maybe give it a small kiss. No, the DB Engine!!!!!!!Now, what's left, oh, the BMW radials & Junker inlines. OUCH! Anyways, I need some rest now as I've been working with some addicts in recovery & some times they don't keep regular hours.

FWIW,
Good Hunting!

For the last link, Google image search.

Yes I have read also that the large quantity of black smoke produced from working the throttle was used as an escape tactic.

A lot of new info has been found in the last 10 or so years.

Heh KK, your needed up top on the tropical filter question.
FWIW,
Good Hunting!