Author Topic: Aircooled engines (Read 672 times)

Charge · « **Reply #15 on:** June 14, 2002, 03:10:20 AM »

I guess that a white smoke pouring from a radial is actually fuel especially if the tanks are of self-sealing type. So the fuel lines of the engine has obvioiusly broken.

I remember an American pilot commenting about FW190 oilcooler that it was actually a rather weak constrution as it had an armored ring in front of it so any, even a small caliber, bullet fired from behind and ricoheting in engine compartment could cause the oil to spill on hot engine. He said that almost every FW he hit from behind started to pour a dense black smoke which was obviously caused by burning oil.

-Charge+

Wilbus · « **Reply #16 on:** June 14, 2002, 06:12:46 AM »

Yes Charge I've read that too, do you have a source where he/any other pilot says those 12 kills were confirmed (did he see the pilot bail out or the plane blow up etc?).

The reason I ask is that, while no other pilot who shot down multiple 190's said that every 190 pored black smoke, or even that a big number of them pored black smoke it might be that every 190 this pilot encountered used teh MW50 boost when they were fired upon. (no not saying the pilot is lying just wanna see some confirmation, interesting reading).

The MW50 boost gave extra power BUT it was also used to "trick" the enemy, when engaged, the MW50 pored out dense grey/black smoke and often fooled many pilots that the plane was dead.

RRAM · « **Reply #17 on:** June 14, 2002, 06:44:32 AM »

Quote

Originally posted by Wilbus

The MW50 boost gave extra power BUT it was also used to "trick" the enemy, when engaged, the MW50 pored out dense grey/black smoke and often fooled many pilots that the plane was dead.

Is that true?...if it is you might be on something good here, wil

AFAIK, what was vulnerable on the 190 was not the oil system (well the anular oil instalation was vulnerable to fire coming from the front), but the fuel injection system wich injected fuel directly into the cylinders. If one of those was blown out, the injection sistem kept on sending fuel to the broken cylinder, thus spraying the engine with high octane aviation fuel...something a bit tricky which causes high probabilities of a fire

but other than that the 190 was renowned for being a very rugged machine, and in any case there are quite many stories around of 190s returning to base in one piece with badly damaged engines, despite the fire hazard already mentioned.

HoHun · « **Reply #18 on:** June 14, 2002, 10:48:21 AM »

Hi RRAM,

>If one of those was blown out, the injection sistem kept on sending fuel to the broken cylinder, thus spraying the engine with high octane aviation fuel...something a bit tricky which causes high probabilities of a fire

Ouch!

But what would happen to a carburetted engine? Wouldn't a damaged line between carburettor and engine mean losing the boost pressure as well as blowing a combustible fuel-air mixture into the damaged engine? I'm not quite sure if any engine could be safe with regard to that type of critical damage.

Regards,

Henning (HoHun)

minus · « **Reply #19 on:** June 14, 2002, 11:31:54 AM »

hmmm so many big enginers around and stuff like this

are ever one of you ever seen the direct injection work ? mean the jet injector and how much fuel it ,, spray,, ?????????

if not then beter checkit out and surely you will be surprised about the volume of fuel

but a broken carburator exposed to air stream , that realy taking fuel around !

Starbird · « **Reply #20 on:** June 14, 2002, 02:16:31 PM »

hahaha

The fuel injector comments remind me of a show that was on the learning channel a number of years ago. I forget the name, or the name of the host. Was this wacky british guy that drew drew some wacky little animations. He would take things apart and show how they work.

Anyhow one episode was about how internal combustion engines worked.

when they got to the part about fuel injectors he had one setup on its side so it would shoot the fuel out horizontally. so he turns it on and fuel goes flying about 10-15 feet. then he takes a torch and ignites it. really neat. the flames went quite a ways..

senna · « **Reply #21 on:** June 14, 2002, 02:23:04 PM »

Yep, most modern day fuel injection systems run about 40 to 60 PSI.

On an engine such as a radial, if a carb or /rod/piston/clylinder was broken, the fuel would stop since that cylinder would stop "breathing" however on say a fuel injected radial like the bmw-801, the fuel would continue to be pumped via its (back then) mechanical system (lower pressures than today I bet). There could be alot of scenereos but good chance of fire.

In regards to the intake system, if an area was "holed" that would cause every cylinder to be affected in terms of manifold pressure or intake charge, the engine could possibly still run but with much reduced power output. Especially a superchared or urbocharged engine since these engines generally had a lower compression value than a normally aspirated engine.

Hooligan · « **Reply #22 on:** June 15, 2002, 09:49:22 AM »

starbird:

That was: "The Secret Life of Machines"

Hooligan

MiloMorai · « **Reply #23 on:** June 15, 2002, 10:10:32 AM »

A desciption of the Merlin

http://www.unlimitedexcitement.com/Pride%20of%20Pay%20n%20Pak/Rolls-Royce%20Merlin%20V-1650%20Engine.htm

and the P&W2800

http://www.stjohnsprep.org/htdocs/sjp_tec/projects/internet/gwojtkun/pr-2800.htm

and here (be sure to look, very interesting)

http://www.nomeking.com/radials.htm

Vector · « **Reply #24 on:** June 15, 2002, 10:57:17 AM »

Quote

Originally posted by RRAM
AFAIK, what was vulnerable on the 190 was not the oil system (well the anular oil instalation was vulnerable to fire coming from the front), but the fuel injection system wich injected fuel directly into the cylinders. If one of those was blown out, the injection sistem kept on sending fuel to the broken cylinder, thus spraying the engine with high octane aviation fuel...something a bit tricky which causes high probabilities of a fire

Oil system and fuel system has some relations.
Spraying fuel into non-functional cylinder would cause fuel not to evaporate enough thus "flowing" from between the cylinder and the piston mixing it with the oil and reducing its lubricating capability. Aviation fuel was high octane fuel, but I doubt it would all evaporate due the engine heat in broken cylinder.

What comes to fuel injection in WWII, we must remember that they actually were not electronically driver systems, they were mechanical. The amount of fuel sprayed into cylinder was way too much just because the clearance between the piston and cylinder was much greater than in present engines. You have any idea of how much oil burn was common in WWII aviation engines? WWII engines had very poor operating efficiency compared to present engines and that is the reason I would rise questions of engines loosing their lubriction capabilities instead of "burning". Sure, if engine runs long enough with reduced lubrication, camshaft and crankshaft would "cut" and make engine to "burn", but not engine to burn directly because of the fuel.
Just my food for thoughts

funkedup · « **Reply #25 on:** June 15, 2002, 12:36:21 PM »

Lots of gun camera footage of 190s getting hit in the forward fuselage and having huge engine fires...

-ammo- · « **Reply #26 on:** June 15, 2002, 12:46:13 PM »

I know this much, if you leave the fuel hose coming from the fuel pump to the carberauter/fuel injection system unhooked and turn the motor over on a early model chevy engine, fuel will squirt a long ways:) lots of it too:)

I put an electric fuel pump on an old camaro my brother and I was souping up in high school. That thing would squirt fuel for 8 feet in a steady stream from 10 foot of hose.

Vector · « **Reply #27 on:** June 15, 2002, 01:06:23 PM »

Quote

Originally posted by funkedup
Lots of gun camera footage of 190s getting hit in the forward fuselage and having huge engine fires...

Caused by.. (fuel or oil)? We never know. Both burns.

Vector · « **Reply #28 on:** June 15, 2002, 01:18:59 PM »

Quote

Originally posted by -ammo-
I know this much, if you leave the fuel hose coming from the fuel pump to the carberauter/fuel injection system unhooked and turn the motor over on a early model chevy engine, fuel will squirt a long ways:) lots of it too:)

Sure will, but we must remember that in aircooled fighter there is huge air velocity in engine compartment due the speed of the fighter and the air velocity of the propeller, that would cause fuel to fall behind (away from the exhaust manifolds) the engine

Besides, fuel as in liquid state, doesn't detonate as easily as fuel steam and air mixture.

senna · « **Reply #29 on:** June 15, 2002, 06:00:57 PM »

Sure carburators sometimes use fuel pumps as well but once the fuel goes into the carburator the pressure is much much lower (in the fuel lines) than in a fuel injected engine.