Fw 190 - GM-1 bottles?

[Krusty]

Black smoke was just an indication that he was running full out, not of any particular boost he was using. The German fuels were coal-based. Even early in the war bomber gunners would shoot at a a 109 or 110 and see smoke and claim a victory, when in fact the German had simply finished his attack run and firewalled the throttle to dive away to safety, the result being a belch of black smoke from the exhausts.

[kilo2]

GM-1 bottle was almost directly behind the pilot in the 152, it contained 22.45 gallons of the nitrous oxide.

[PR3D4TOR]

Black smoke was just an indication that he was running full out, not of any particular boost he was using. The German fuels were coal-based. Even early in the war bomber gunners would shoot at a a 109 or 110 and see smoke and claim a victory, when in fact the German had simply finished his attack run and firewalled the throttle to dive away to safety, the result being a belch of black smoke from the exhausts.

Lol, you make it sound like the German planes needed a stoker.

True, the German Fischer–Tropsch process produced synthetic fuel from coal, but being ultra-clean and low sulfur it was actually of a higher quality than gasoline refined from oil. Any smoke produced by German aero-engines had nothing to do with fuel quality, but probably more to do with running a very rich mixture to increase cooling of the cylinder heads at high boost levels. Even more so if GM-1 was being used.

In these oil starved days the Fischer–Tropsch process is again being used to produce fuels, this time in the U.S. The Air Force is trying a 50/50 blend of JP8 and synthetic fuel to lessen the reliance on imported oil.

[MiloMorai]

I have heard of 109 pilots using a tactic that caused the engine to smoke heavily. They would fall off like they had been hit and the attacking pilot would then break off the attack.

[PR3D4TOR]

Old school cheaters! 

[Krusty]

Lol, you make it sound like the German planes needed a stoker.

I did no such thing. If you want to start a debate about what was richer, or higher quality, feel free. That's beside the point that the engines belched black smoke trails when pushed. This is readily evident in most war-time photos, as the staining on Heinkel wings took over the camo in most cases. It was very heavy on planes that weren't kept constantly clean.


Whatever other merits you want to argue, you can't deny it was dirty exhaust..

[PR3D4TOR]

I think you'll find that on all aircraft with inverted cylinders.

[Krusty]

No, once again you don't understand. The B-17 stains are not exhaust, they are oil. The exhaust was out of the bottom turbocharger.

The German fuel made a noticable cloud of smoke. Enough so, that enemies that saw it thought they had scored killing hits on it.

Front-line, top-tier fighters were regularly cleaned by ground crews as a matter of moral, maintenance, and of pride, however others (i.e. not bf109s) often faired worse. There are cases where cleaning even the front-line fighters was hard to do, such as in the desert. There you see what the planes looked like with regular use.



This 110 has large swaths of its upper and lower wings covered as well as most of the cowling, but the exhaust is so thick it extends back and obscures most of the vertical stabilzers as well.



On bombers it was particularly noticable.





Anybody who knows what they're talking about knows that German fuels belched smoke. Lots of it. This is told in tales from both sides, anecdotally, and recorded in the majority of wartime photos.

[PR3D4TOR]

Again... Inverted cylinders. Nothing to do with the fuel. All engines with inverted cylinders collect lubrication oil in the cylinders. When the engine is started this oil is ejected into the exhaust manifold where it evaporates and spews out the exhaust stacks... onto the aircraft.

http://www.youtube.com/watch?feature=player_detailpage&v=mzgYkfq9OVw#t=104s

This 109G-4 is not running on German wartime synthetic fuel and the soot is still clearly visible on this well cared for show-bird.


Here's a B-17 starting up with half its cylinders full of oil:

http://www.youtube.com/watch?v=rAk9Ap0tyLI

Again, nothing to do with the fuel.


Restored 109G-6:



Again, no German wartime fuel.

Inverted cylinders.

[MiloMorai]

Upright cylinder engines smoked on start up.

http://www.youtube.com/watch?v=BzVBlMXJDms&feature=related

[PR3D4TOR]

Smoke yes. Spewing hot oil vapor, no. Injecting oil into the exhaust manifold is what show planes do to create smoke. It is thick and white, but leaves a sooty oily residue on anything it touches. Like the wingroot of this biplane: http://www.youtube.com/watch?v=yvGZQFra78c


190A-5 startup: http://www.youtube.com/watch?feature=player_detailpage&v=Y2BZnSYTRrI#t=101s

Bristol Hercules: http://www.youtube.com/watch?feature=player_detailpage&v=J0q9l8xejrE#t=14s

[PR3D4TOR]

Black smoke = Uncombusted fuel vapor. White/blue smoke = Vaporized oil.

[PR3D4TOR]

This one is extreme: http://www.youtube.com/watch?v=IWj3oLjHEJY

It's been "pickled" so all its cylinders are oily.

[Babalonian]

Again... Inverted cylinders. Nothing to do with the fuel. All engines with inverted cylinders collect lubrication oil in the cylinders. When the engine is started this oil is ejected into the exhaust manifold where it evaporates and spews out the exhaust stacks... onto the aircraft.

http://www.youtube.com/watch?feature=player_detailpage&v=mzgYkfq9OVw#t=104s

This 109G-4 is not running on German wartime synthetic fuel and the soot is still clearly visible on this well cared for show-bird.


Here's a B-17 starting up with half its cylinders full of oil:

http://www.youtube.com/watch?v=rAk9Ap0tyLI

Again, nothing to do with the fuel.


Restored 109G-6:

(Image removed from quote.)

Again, no German wartime fuel.

Inverted cylinders.

I see smoke that's typical of a radial engine until it warms up and its seals expand just enough to make everything running tight inside just right... where is this half-the-cylinders worth (a couple gallons worth I'd think) of accumulated oil being spewed out?

[PR3D4TOR]

Oil vapor... The accumulated oil in the lower cylinders are ejected into the exhaust manifold where it vaporizes.

I was hoping I wouldn't have to go into detail, but here it goes...

If a radial or inverted-V engine hasn't been rotated for a day or more you'd need to hand crank the engine a few revs to pump the oil out or you'd risk liquid lock. You can never be too careful with inverted cylinders. I'm sure you've seen ground crew hand pulling revs on the props of B-17s and other radial engined planes plenty of times in videos, or even in the movies.

The oil comes out of the big Pratts and Wrights so slowly that you'll pull through a couple of blades fairly easily and then it suddenly comes to a stop, and then you're heaving, or rather leaning on the blade as it moves ever so slowly as the oil pours out, then frees up for another few blades until it comes to the oiled pot again which pulls through with less resistance than before and produces another run of oil, and the third time around the resistance is pretty even. Then you can try a start, but its going to be a while running on 8 or 16 before the fuel washes the plugs on the bottom cylinders clean enough to fire. Nine blades by hand in the normal direction of rotation on a DC3 to make sure it was OK to start. Even after pulling through 9 blades there's gallons of the stuff still swilling around. If you encounter a liquid lock remove lower plugs and move the prop until all the oil is out.

Also, with many radial engines, if it's not run for more than a few days it's cowlings off and take out the drain plugs in the inlet pipes of the lower cylinders. Oil can collect there and it won't come out by hand pulling it through as the "elbow" in those inlet pipes is below the level of the exhaust valves. So any oil stays there until start up, whereupon it gets sucked into the cylinder where it can cause a lock. If you are lucky, the engine breaks there and then and you get you wallet out. If you are unlucky you bend a con rod and the engine fails some time later, and somewhat dramatically, as the rod breaks in the air one day.

Oil consumption in flight was also higher with inverted cylinders, radials in particular, for the R3350 (B-29) acceptable oil consumption in flight was 3 gallons per hour. The B-17 has a 37 gallon oil tank per engine.

If you for some reason don't take my word for it: http://www.youtube.com/watch?v=UD910YCkLn0