Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: SgtPappy on September 11, 2009, 04:49:33 PM
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Why is it sometimes oil drips out of one of some aircraft's many orifices and it's considered 'normal'?
A lot of airworthy planes on display will have pans under such said parts which will regularly drip a tiny a mount of oil. Spitfires for example, actually drip oil from the rad housing. I always supposed it was lubrication for parts, but something like a radiator door should be lubed with either grease or oil from say an oil can. Dripping oil looks like there's some kind of reservoir leaking.
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Why is it that the SR-71 leaks fuel like a sieve before a flight? It is the way it is. :D
Actually, in the case of the Blackbird, the skin has gaps in it to allow for the expansion at high mach speeds, which then seal it up nicely.
So aside from not answering your question with any authority, until someone who knows (or cares) comes along to answer you, "it is the way it is" will have to suffice.
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I'd be worried if they were not leaking because that means they're out of oil.
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Reminds me of the "hotseat" in a CH53.. Back in the day, there was a certain spot in CH53, where noone would sit, (no one who knew better)... Because above the overhead, was an oiltank.. When the oil got BLAZIN hot, it would overflow the tank, and drip thru the overhead panels, down the neck of anybody who sat in the "hotseat"... Hot oil burns Deep into flesh, ya know!!! I still have scars from it, LOL!!!
It was common practice to make sure the Noobs all got their turn!!! :devil
RC
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The standard routine for shutting down a radial powered aircraft after being chocked includes throttles to idle, mixtures to idle cutoff, magnetos off, battery off. Finally, drip pans under the engines.
Most radials leak oil like Chris Matthews leaks brain cells.
My regards,
Widewing
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Haha, wow WW, good one.
Would it have something to do, like ImADot said, about heat expansion? Perhaps a cooling engine would release oil out its crevices. After all, oil does get past the piston rings. Though I still don't know why it can come out a Spit's rads.
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The standard routine for shutting down a radial powered aircraft after being chocked includes throttles to idle, mixtures to idle cutoff, magnetos off, battery off. Finally, drip pans under the engines.
Most radials leak oil like Chris Matthews leaks brain cells.
My regards,
Widewing
Wow, that's almost the exact same procedure as my Panhead!
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...Spitfires for example, actually drip oil from the rad housing...
And everywhere else. Gotta love British 'engineering'.
(http://www.historyofwar.org/Pictures/spitfire_XII.jpg)
(http://cdn-www.airliners.net/aviation-photos/photos/0/5/6/1128650.jpg)
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PFFT all spits come with an emergency oil leak system that only gets used in the rare occurance that a bandit can actually get on your 6 and stay there !!
Think James Bond ;). Shoot me now with oil over your cockpit!! :devil.
2 very pretty pictures though :D
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Classic joke: WWWHHHYYYYYyy do Brits not make computers? They can't figger out how to make em leak oil :D
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Corsairs were also pretty notorious for throwing oil. Early Birdcages had cowl flaps that went all the way around, and were so bad about splattering oil all over the wind screen that ground crews permanently jammed the top four shut. They were eventually removed on the production line.
They also saw heavy leaking and staining around the oil cooler exhaust.
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the FA18 leaks oil when its not on... had to clean it up at an airshow.
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Sounds like there were no viable means of keeping oil in where it needed to be all the time.
Oil coolers, I suppose leak due to those small perforations in the cooler itself, and the full cowl flap birdcage F4U-1's was really a technical problem.
Looking at the Spit, there's oil behind the cab intake and even from small holes near that which look like their sole purpose is to let oil drain.
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I recall there is a special small container in P-51 which collects the oil spill from valve stack and dumps it out when the engine is running. Somewhere near exhaust stack?
-C+
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I recall there is a special small container in P-51 which collects the oil spill from valve stack and dumps it out when the engine is running. Somewhere near exhaust stack?
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Thats that plume of oil you see coming out of the hole on the right lower side of the cowling on Merlin 'Stangs.
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Ah that's interesting.
Now is this, as Treize69 puts it, 'British engineering' or is it something that's common on all piston aeroengines? Widewing already stated that Twin Wasps leak a lot.
If so, I guess there is just no way to keep oil completely sealed in every system it lubricates.
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"Now is this, as Treize69 puts it, 'British engineering' or is it something that's common on all piston aeroengines?"
I have seen pictures of both 109s and 190s with rather messy bellies so I'd think it is quite normal.
And bluish smoke in start-ups, I'd think thats oil burning. Did those engines even have valve guide seals at all?
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I was just being my normal anglo-degrading self. Please to be taking with a grain of salt. :)
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And everywhere else. Gotta love British 'engineering'.
There's a Lucas Electrics joke in there somewhere :D
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There's a Lucas Electrics joke in there somewhere :D
Ah, Lucas, Prince of Darkness..... Every Brit car I ever owned (many) would have baffled Tesla.
My regards,
Widewing
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I was just being my normal anglo-degrading self. Please to be taking with a grain of salt. :)
Oh pft. Don't worry bout it Treize. What I said was simply just quoting you; I'm sure none of us take offense. :)
Yes, Charge. Blue smoke means oil is burning. I'm not sure, but from what I've heard, Allison engines had more complicated, but better valve systems than the Merlin. There are, after all, a lot of innovations in current piston engines like valve taper, fuel injection and other things that make todays engines super-efficient.
That is weird though. You'd think for such awesome engines, valve guides and seals would be much better suited to keeping oil out of the manifolds.
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Radials do not leak. They're just marking their territory. (Sign seen under an F4U)
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Radials do not leak. They're just marking their territory. (Sign seen under an F4U)
I like that one. :D
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Look WWII aircraft are kinda like Harely Davidson motorcycles. If they aint leaking something there's a problem.
You just have to nod your head and repeat this phrase, "I believe" over and over again.
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Look WWII aircraft are kinda like Harely Davidson motorcycles. If they aint leaking something there's a problem.
You just have to nod your head and repeat this phrase, "I believe" over and over again.
I was actually going to mention BSA and triumph. Oil leaks and the prince of darkness.
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A lot of the oil that ends up under a radial gets there during startup when it's puked out of the lower cylinders.
Those "leaks" you see under aircraft that stream back from airflow are many times oil breather lines.
Even a small amount of oil spilled onto the engine when adding oil makes a big mess.
No reason a radial is going to leak any more than any other piston engine if well maintained. The problem being there are about a bazillion places for small leaks to occur...such as each end of the pushrod tubes.
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The problem being there are about a bazillion places for small leaks to occur...such as each end of the pushrod tubes.
Doesn't help that, on a radial, 1/4 to 1/3 of the cylinders are upside down...
Now that I think of it, I wonder how messy V and inline inverts were? I've never had the pleasure of wrenching on any, so I wouldn't know.
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And I suppose the technology put into making oils and the smaller, more precise tolerances and clearances in engine measurements allow for much less, if any oil leakages in current vehicles.
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PCV systems and better sealing materials.....
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And I suppose the technology put into making oils and the smaller, more precise tolerances and clearances in engine measurements allow for much less, if any oil leakages in current vehicles.
It may also be just a simple matter of fewer places to leak from. Unlike aviation engines, the cylinders in most automotive engines, for the last few decades anyways, are formed into one or two banks that connect to the crank case. This is contrasted with aviation engines, and even some motorcycle engines, where the cylinders attach individually. Fewer mating surfaces means fewer places for leaks to start.
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Ah, Lucas, Prince of Darkness..... Every Brit car I ever owned (many) would have baffled Tesla.
:rofl