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Engine Oil

Posted: Wed Oct 06, 2004 1:42 am
by Christian
Hur much oil does a aircraft engine contain, and what kind of oil do they use, for an example in the PW4056 on the B-747-400?

RE: Engine Oil

Posted: Wed Oct 06, 2004 2:05 am
by MD11Engineer
First, what engine are you talking about? Turbine engines or piston engines?

A common brand for turbines is Mobil Jet 2, but the maintenance manual of the engine manufacturers lists several approved brands, like Exxon, Aeroshell or BP Aero oils.
The main thing is that you are not allowed to mix different brands, weven if they are approved for your engine.

The quantity can be as small as 5 quarts for a RR Tay engine or as big as 26 quarts on a PW 4000.

A quart is a little less than one litre.



Jan

[Edited 2004-10-05 19:06:19]

RE: Engine Oil

Posted: Wed Oct 06, 2004 2:09 am
by Christian
Thanks for the quick answer.
I'm talking about a turbine engine.

RE: Engine Oil

Posted: Wed Oct 06, 2004 6:16 am
by Dalmd88
Turbines use a synthetic oil. Pistons use stuff similar to auto oil, most people use semi-synthetic or full synthetic. They hold up longer than Dino oil.

RE: Engine Oil

Posted: Wed Oct 06, 2004 7:02 am
by A/c train
my companys fleet,
757 - RB211-535-E4 - 19 left / 20 right (quartz) ex aeroshell 560 now BP2197
321 - V2500 - 22.5 and above is good. (BP 2197)
320 - CFM-56 - 18 and above is good (aeroshell 560)
but the oils which are synthetic, are within the limits of manufacturer, simply customer preference, the engine oil/IDG oil and starter oil are all compatible. Each companys R+D dept will decide which oils perform better and will raise SB's for programmes to change the oils used on each type.
regds a/c

RE: Engine Oil

Posted: Wed Oct 06, 2004 8:05 am
by LMP737
The Trents on our 777 have a 25 quart capacity and use BP2197, as do all our other aircraft. We still use 2380 in our starters and will continue to do so till our stock of 2380 goes away. Or so I have heard.

RE: Engine Oil

Posted: Wed Oct 06, 2004 8:40 am
by LineMechQX
PW150A's on the q400's hold nearly 40 qts, but of course thats including a very large ACOC (air cooled oil cooler) and the RGB(reduction gear box) and of course the prop systems. All of which run in the same oil system (not seperated). Some people don't believe me, but trust me I've been in Montana on a cold winter night, changing out the oil, with only 30 qts that we brought with us, having to buy 10 more from the local FBO. This was after a oil overtemp, where as all the oil had to be drained and filters changed. I'm sure useable is more around 20 or so.

Late PC

RE: Engine Oil

Posted: Wed Oct 06, 2004 8:41 am
by L-188
Depends on the engine.

Manufactures will recommend different oils for different conditions or engines.

Just remember on a radial, if it ain't leaking....it's out!!!

RE: Engine Oil

Posted: Wed Oct 06, 2004 9:08 am
by Gecko
On older style turboprops eg RR Tyne or the Ivchenko AI-20 series use a sythetic/mineral mix - I forget the exact mix but I think it was 1/4 Aeroshell 100 to 3/4 Aeroshell Turbine 3.

Another oil that is used when available with the same properties as the mix is Aeroshell 750. It is preferred by the tech crew when available because it doesn't need to be mixed with anything.

There are many other oil brands available though essentially they are meant to perform the same way although it is forbidden to mix different brands or types of oil.

As for capacity for these engines it is around 20 litres.

RE: Engine Oil

Posted: Wed Oct 06, 2004 3:38 pm
by videns
There are many other oil brands available though essentially they are meant to perform the same way although it is forbidden to mix different brands or types of oil.

Is there a regulation not allowing to mix different oils? If so, are you supposed to drain the oil before adding a new one in?
What are the limits (and how do you measure that) for the remnant oil left behind after draining?

v

RE: Engine Oil

Posted: Wed Oct 06, 2004 3:54 pm
by Gecko
Sorry Videns I should clarify, you are able top-up using exactly the same brand and type oil, though you are unable to top-up using a different brand or designation. Even though these oils are meant to do essentially the same job as each other they may not be compatible.

In short, if you want to use a different oil as what is in the system you must drain and flush the entire engine including filters.

RE: Engine Oil

Posted: Wed Oct 06, 2004 4:06 pm
by L-188
Videns, oil type would be specified by manufactures manual not by regulations.

And if you wanted to change oils, you would have to follow the manufactures Instructions/Manuals/Service Bulletians, which will typically involve a process like Gecko mentioned.

RE: Engine Oil

Posted: Thu Oct 07, 2004 12:29 am
by northseatiger
The Makila uses AS500 on the 1A variant and the tank holds 7l pre-mod and 4.5 post mod tank.

RE: Engine Oil

Posted: Thu Oct 07, 2004 12:38 am
by Christian
Thanks for all the answers.

Another question: What's the diffrence between engine oil for an aircraft engine, turbine engine again, to a car engine??

RE: Engine Oil

Posted: Thu Oct 07, 2004 12:49 am
by MD11Engineer
Typically turbine oil doesn´t get contaminated with combution products, like piston engine oil does, but gets exposed to higher temperatures.
The viscosity has to be the same over a wide range of temperatures.
Turbine oil gets rarely changed, usually only topped up. And even after months in an engine it still looks like new. If it turns black it is a sign that something went seriously wrong with the engine, e.g. a bad bearing seal.

Jan

[Edited 2004-10-06 17:50:19]

RE: Engine Oil

Posted: Thu Oct 07, 2004 8:40 am
by Gecko
If you find metal in it you are in for some work, especially on some of the older high wing turboprops, I have seen three engines changed on AN-12's. Each time it took 5-6 days, mind you the engineers in this case didn't have the luxury of a hangar and its facilities.

The most difficult repair I have seen on an AN-12 was the replacement of the three inboard fuel bags on the starboard wing. It was an 8 day repair!


RE: Engine Oil

Posted: Thu Oct 07, 2004 11:04 am
by TimT
The turbine engines, (P&W,RR,GE,CFM) all use ball bearings and the oil is literally sprayed on the races to lube and cool them. An automotive engine and an aircraft piston engine both use a shell-type bearing that is lubricated by a film of oil. Ideally, the rotating mass never actually touches the bearing, but rides on that oil film. Following that, the shear strength of a synthetic turbine oil is nearly zero, while the shear of a piston engine oil has a much higher number. When the turbine engines first strted to appear, some of the old airline guys were going to save some cash and steal oil for their cars, thinking if it's good enough for a jet, it should be great for a car. They all got to buy new engines.

RE: Engine Oil

Posted: Fri Oct 08, 2004 2:34 am
by IL76TD
we use this shizzle that comes in big drums labeled "turbonycoil" with a bunch of other russian shizzle written on them

crews don't seem to mind

RE: Engine Oil

Posted: Fri Oct 08, 2004 8:47 am
by Gecko
We use Turbonyoil also, normally when an aircraft come back from a major check and brings a load of spares, tyres and oil. Until that runs out and usually the Russian guys don't want to spring for the freight to bring some more out so we just switch to the Aeroshell.

RE: Engine Oil

Posted: Sat Oct 09, 2004 9:41 pm
by IL76TD
gecko,

do you guys fly an-12's or il76's


RE: Engine Oil

Posted: Mon Oct 11, 2004 1:14 pm
by Gecko
IL-76TD

We use AN-12's mostly, we use the odd IL-76 when the AN-12 is unsuitable.

Flown on the AN-12 plenty of times, its great especially if you have a non-smoking crew, most times they have a bed which is great on long trips.

RE: Engine Oil

Posted: Mon Oct 11, 2004 10:30 pm
by northseatiger
Ooops MGB = AS500 Engine = AS555, how to remember, the engine goes faster than the gearbox !!

RE: Engine Oil

Posted: Tue Oct 12, 2004 2:41 am
by Buzz
Hi Christian, Buzz here. Back to one of your questions, the difference between turbine engine oil, Recip engine oil, and auto engine oil:

Turbine oil has been fairly well discussed, it's synthetic and made to run at much higher tempertures than Recip oil.

The oil we use in reciprocating engines varies a bit, one difference is if you operate a big radial engine you generally buy oil by the barrel: a DC-3 has 29 gallon oil tanks, we fly with about 25 gallons aboard, and we plan on an oil burn / drip / loss of about 1 or 2 gallons of oil per hour per engine. Other engines are higher... the B-29 has 55 gallon oil tanks for the R-3350 engine. As MD11 Engineer pointed out, "products of combustion" : carbon, avgas, water seep into the oil supply so you change oil often.

Recip oil comes in straight weight: SAE50, SAE60. Multi viscosity is becoming widely available now, i use 15-50 Aeroshell in the taildraggers i fly around for fun. The Aeronca Champs and Piper Cubs have "flat" engines. Phillips makes an oil for Radial engines, it's also multi-vis.

In WW2 the engine oil would accumulate sludge in the nooks and crannies, it was often called "Mineral" oil and had few additives. In the '50's "Detergent" oil came out which causes the sludge to circulate through the engine, many people back then figured it was a bad thing to use it in an old engine.
Now there are "ashless-dipsersant" oils that don't clean the engine, but keep the microscopic bits in suspension until you drain oil. And the additives don' t leave much of a residue (the ashless part) if they get burned: leaky rings.

Auto oil has different additives to improve wear compared to Recip oil, many auto oils have a phosphorous compund which works great. Many large radials have silver plated main bearings, and the phosphorous destroys the silver, so that's one reason to follow the manufaturer's list of recommended oils.

When the original engine builder doesn't support your enigine anymore (Pratt + Whitney lost interest in their radial engines) then we ask the rebulder, Precision Airmotive near Seattle is a 2nd source.
g'day
Buzz Fuselsausage: Line Mechanic by night, DC-3 Crew Chief by choice, taildragger pilot for fun.