Hi, I am currently working on my ppl, and I am wondering what the difference is between 15W50 and 20W50 oil, and if it matters which one you use?
The 172 that I am currently training on says to add oil when the dipstick reads between the 4 and the 5, so say if the oil is at the 5, and I have a cross country, should I just add 1 quart of oil anyways, or would it already be sufficient? How long does it take for a typical 172 to burn a quart of oil?
Thanks for the help
Oil in 172
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Hawkeye4077
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Re: Oil in 172
If it was at 5 before a x-country I would add one. Whenever I fly a 172, I keep it between 6 and 7. When it gets close to 5 I put one in. ( oil is cheaper than an engine) . But if you put too much in it, it will just get out the overflow and make the belly of the airplane dirty.
Also. Take some time next time you go and check the airplane journey log. Hopefully, ppl write in the remarks column when they put oil in so you can see how long it takes before it burns a Qt. 1 Qt for every 8-9 hours flown would be resonable but it doesn`t mean the engine is gonna quit on you just because it takes a Qt every 3 hours. Ask your instructor to get you a copy of the Engine Operating handbook NOT THE AIRCRAFT POH ( If he know such thing exists) and read up about oil and you`ll learn all about oil comsumption.
I hope this will help and invite others to add up/correct me if I said something wrong. The above is from previous experience and it is just how I do things so it`s worth what you paid for it.
Happy landings
Hawk
Also. Take some time next time you go and check the airplane journey log. Hopefully, ppl write in the remarks column when they put oil in so you can see how long it takes before it burns a Qt. 1 Qt for every 8-9 hours flown would be resonable but it doesn`t mean the engine is gonna quit on you just because it takes a Qt every 3 hours. Ask your instructor to get you a copy of the Engine Operating handbook NOT THE AIRCRAFT POH ( If he know such thing exists) and read up about oil and you`ll learn all about oil comsumption.
I hope this will help and invite others to add up/correct me if I said something wrong. The above is from previous experience and it is just how I do things so it`s worth what you paid for it.
Happy landings
Hawk
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iflyforpie
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Re: Oil in 172
I have operated 172s between 4 and 5 quarts but between 5 and 6 seems to work a bit better for ours. Anything above 6 will do a nice job of lubricating the belly on most 172s, the seventh quart being blown out the breather and usually drawing the 6th quart out with it.
I've had great luck with both the 15W50 (Aeroshell) and the 20W50 (Phillips) although the 15W50 seems to break down easier in the heat (reverting to a 15 weight oil as the viscosity improvers give out). We run straight grades in the summer...
For which oil to add, check in the journey log at the last oil change or inspection to see what type of oil they used. This is important because if the engine was just overhauled (major or top), it would still have break in oil in it (this is what you would have to add).
I've had great luck with both the 15W50 (Aeroshell) and the 20W50 (Phillips) although the 15W50 seems to break down easier in the heat (reverting to a 15 weight oil as the viscosity improvers give out). We run straight grades in the summer...
For which oil to add, check in the journey log at the last oil change or inspection to see what type of oil they used. This is important because if the engine was just overhauled (major or top), it would still have break in oil in it (this is what you would have to add).
Geez did I say that....? Or just think it....?
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paydaymayday
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Re: Oil in 172
Each engine has it's own oil habits - this goes for everything from small pistons, to large turbines. For example, on one of the King Air's I fly, I can fill one side up to 2 quarts below full and it will burn that quart over a good 50 hours. If I fill the other side up like that, it will just piss it out until it's 3 and a half quarts below full and burn that half quart in less than ten hours. They are both perfectly good engines, they just have their own oil personalities.
This is why it's a good idea to talk to someone who regularly flies that particular aircraft. Learn its quirks and its personality. Go through the journey log to see how frequent the oil change intervals are. This will give you a chance to see any recurrent issues or snags that come up, as well. Know your airplane.
As for your initial question - the difference between 15W50 and 20W50, the numbers refer to the viscosity of the oil. The higher the number, the more viscous it is (it flows slower and is thicker). You see that there are two numbers: A winter viscosity and a summer viscosity. These are called multiviscosity oils.
The first number (15W or 20W) is the winter viscosity (hence the W). Since oil becomes more viscous (flows slower) in cold temperatures, you need a thinner oil. The second number is the summer viscosity.
I would personally not suggest mixing oil viscosities. Go with what the POH says, and then go with what was previously put in the aircraft.
This is why it's a good idea to talk to someone who regularly flies that particular aircraft. Learn its quirks and its personality. Go through the journey log to see how frequent the oil change intervals are. This will give you a chance to see any recurrent issues or snags that come up, as well. Know your airplane.
As for your initial question - the difference between 15W50 and 20W50, the numbers refer to the viscosity of the oil. The higher the number, the more viscous it is (it flows slower and is thicker). You see that there are two numbers: A winter viscosity and a summer viscosity. These are called multiviscosity oils.
The first number (15W or 20W) is the winter viscosity (hence the W). Since oil becomes more viscous (flows slower) in cold temperatures, you need a thinner oil. The second number is the summer viscosity.
I would personally not suggest mixing oil viscosities. Go with what the POH says, and then go with what was previously put in the aircraft.
Last edited by paydaymayday on Mon Sep 21, 2009 11:08 pm, edited 2 times in total.
Re: Oil in 172
http://www.lycoming.textron.com/support ... index.html
Lycoming has a great website.
I used to fill it right up to eight after each oil change as the engine relies on splash lubrication for the top of the engine,so if it blows a little out on take off at least the top has been well lubed.And the oil splashing around the top protects the crank from rusting .If the crankcase vent is set right he oil should calm down to about seven so i would add it at just below seven so as to kep the top lubed.Got over three thousand hours out of some engines by keeping the oil up.One guy who kept his oil at 3 to four and ran his engine on crap gas did not make TBO.But he did save about a hundred bucks on oil.
When in doubt as to what type of oil to use ,check the Aircraft Journey Log as the last oil change is usually written in the journey log book and will tell you what the last brand and type of oil was installed in that particular aircraft engine.The front page will tell you the generic oils you may use ,but look for the last maintenance event like a fifty hour inspection or one hundred hour inspection to see what type of oil is actually in the engine.
Or you could ask someone at the flight school as there are no such thing as dumb questions and the more you ask the more you may learn.
Lycoming has a great website.
I used to fill it right up to eight after each oil change as the engine relies on splash lubrication for the top of the engine,so if it blows a little out on take off at least the top has been well lubed.And the oil splashing around the top protects the crank from rusting .If the crankcase vent is set right he oil should calm down to about seven so i would add it at just below seven so as to kep the top lubed.Got over three thousand hours out of some engines by keeping the oil up.One guy who kept his oil at 3 to four and ran his engine on crap gas did not make TBO.But he did save about a hundred bucks on oil.
When in doubt as to what type of oil to use ,check the Aircraft Journey Log as the last oil change is usually written in the journey log book and will tell you what the last brand and type of oil was installed in that particular aircraft engine.The front page will tell you the generic oils you may use ,but look for the last maintenance event like a fifty hour inspection or one hundred hour inspection to see what type of oil is actually in the engine.
Or you could ask someone at the flight school as there are no such thing as dumb questions and the more you ask the more you may learn.
Re: Oil in 172
About the amount of oil in a 172: different 172 models have different engines, with different oil capacities.
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iflyforpie
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Re: Oil in 172
99% of flight school 172s have the O-320 or O-360 Lycomings, which each have an 8 quart oil sump. Engines with external oil filters require an extra quart or so during changes (usually 7 vice 6), but that doesn't change the operating level on the dipstick.
Geez did I say that....? Or just think it....?
Re: Oil in 172
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Last edited by Hedley on Sun Nov 08, 2009 9:26 pm, edited 1 time in total.
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office_supply
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Re: Oil in 172
On that subject, I have found that I get a lot of oil on the belly (blow by?). I run 15W50 summer and winter but Im considering instead doing 15W50 in the winter and perhaps something like 80 or 100 in the summer. Any suggestions?
Its an O-235-C2C engine which tends to blow out anything above 4.5 quarts (6qts total sump)
The only thing that I think could be an issue is that the engine tends to run rather hot (oil temp usually between 180F and 275F on the gauge) and I dont have a filter on the engine, just screens.
/didnt mean to change topic
Its an O-235-C2C engine which tends to blow out anything above 4.5 quarts (6qts total sump)
The only thing that I think could be an issue is that the engine tends to run rather hot (oil temp usually between 180F and 275F on the gauge) and I dont have a filter on the engine, just screens.
/didnt mean to change topic
Re: Oil in 172
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Last edited by Hedley on Sun Nov 08, 2009 9:24 pm, edited 1 time in total.
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office_supply
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Re: Oil in 172
Thanks Hedley,
What Im thinking I'll do is change oil in October to 15W50 for the winter months, and then again in April to W100 Plus for the summer months.
I do preheat in the winter, I have a small 900W electric heater that rests on the bottom cowling blowing hot air on the oil sump. With the winter cover on, takes about 1.5 to 2.5 hours to warm up the engine nicely.
I do have the cowling off often (in fact had it off all week doing my panel overlay change) and I have noticed there are two gaps in the metal surrounding the engine. About 1 to 2 inches square each. The baffle seals could perhaps get changed. Two annuals ago the baffle 'stiffener' and 'seals' were repaired. I've been considering ordering new seals for a while now and getting them replaced at next annual.
On the air/oil seperator, first time I hear of this device, at the risk of sounding like a newb (because, really, I am) how exactly does it work and what does it do? (apart from seperating air and oil, which is slightly obvious)
How much do they weigh and what do you figure an approx installation cost/time would be? They sound really worth it if they'll help cool the oil and prevent me getting on my back every so often to wipe the belly!
What Im thinking I'll do is change oil in October to 15W50 for the winter months, and then again in April to W100 Plus for the summer months.
I do preheat in the winter, I have a small 900W electric heater that rests on the bottom cowling blowing hot air on the oil sump. With the winter cover on, takes about 1.5 to 2.5 hours to warm up the engine nicely.
I do have the cowling off often (in fact had it off all week doing my panel overlay change) and I have noticed there are two gaps in the metal surrounding the engine. About 1 to 2 inches square each. The baffle seals could perhaps get changed. Two annuals ago the baffle 'stiffener' and 'seals' were repaired. I've been considering ordering new seals for a while now and getting them replaced at next annual.
On the air/oil seperator, first time I hear of this device, at the risk of sounding like a newb (because, really, I am) how exactly does it work and what does it do? (apart from seperating air and oil, which is slightly obvious)
How much do they weigh and what do you figure an approx installation cost/time would be? They sound really worth it if they'll help cool the oil and prevent me getting on my back every so often to wipe the belly!
Re: Oil in 172
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Last edited by Hedley on Sun Nov 08, 2009 9:22 pm, edited 1 time in total.
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office_supply
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Re: Oil in 172
I'd take a hell week over a 5 month downtime! (which has been roughly the length of time taken for my first two annuals)Hedley wrote:Don't defer snags. Fix stuff that's broken NOWreplaced at next annual
so that your annual isn't hell week.
How does the SAE scale work? I thought 15W50 's '50' was SAE 50. Good to know because the POH recommends SAE 50 in the summer. Had I known that was W100 I would have changed a long time ago!
On the sticking valve note, does running the engine lean for a minute or two before shutdown (1200-1300rpm) help with that? During my PPL training I was told to do this to help clean plugs and its a habit I've kept since.
Thanks for all the info Hedley
