Gatlin Gun Posted May 19, 2019 Report Share Posted May 19, 2019 (edited) Ok... I've heard all these horror stories about "1 quart an hour" and how much oil their birds use. Mines uses NONE. It's still new-to-me, so I'm learning her personality, but she uses NO oil. I.e. I've never had to add any. Is that "awesome! Lucky you! The motor is soild" or is something off/wrong? Edited May 19, 2019 by Gatlin Gun Quote Link to comment Share on other sites More sharing options...
jaylw314 Posted May 19, 2019 Report Share Posted May 19, 2019 Not to rain on your parade, but it is at least possible that if a motor does not get enough oil to the piston rings, it would not use up any oil. Seeing 1 qt every 8-12 hours seems typical and is reassuring that oil is getting to where it needs to be. Quote Link to comment Share on other sites More sharing options...
lifendet Posted May 19, 2019 Report Share Posted May 19, 2019 How much hours since last oil change? Quote Link to comment Share on other sites More sharing options...
ArtVandelay Posted May 19, 2019 Report Share Posted May 19, 2019 Do you have an air/oil separator?Tom 1 Quote Link to comment Share on other sites More sharing options...
FoxMike Posted May 19, 2019 Report Share Posted May 19, 2019 A few years ago a retired airline pilot flew a Lancair from Guam to Jackville, Fl. non stop . He was in the air 36 hours. After landing he checked the oil quantity and it was the same as when he left Guam. Quote Link to comment Share on other sites More sharing options...
Shadrach Posted May 19, 2019 Report Share Posted May 19, 2019 (edited) 14 hours ago, Gatlin Gun said: Ok... I've heard all these horror stories about "1 quart an hour" and how much oil their birds use. Mines uses NONE. It's still new-to-me, so I'm learning her personality, but she uses NO oil. I.e. I've never had to add any. Is that "awesome! Lucky you! The motor is soild" or is something off/wrong? Not good, awesome or lucky you. I would monitor it very closely and ensure that you’re seeing what you think you’re seeing. From Mike Busch’s 10 biggest lies about piston aircraft engines: Lie #5:The less oil an engine burns, the better. Get a few aircraft owners get together over a few beers, and inevitably the conversation turns to oil consumption. "I'm only using a quart in 30 hours," one will say. "That's nothing," brags another owner, "I don't have to add any make-up oil between 50-hour oil changes!" The owners doing this bragging probably don't realize that they probably won't make it to TBO without a costly mid-term top overhaul! It turns out that ultra- low oil consumption is often a bad omen when it comes to cylinder longevity.For a cylinder to make it to TBO, it must be protected from metal-to-metal scuffing by the piston rings. This protection comes from a film of oil that coats the cylinder barrel and causes the rings to "hydroplane" instead of scuffing the barrel. Now, if the cylinder barrel is properly coated with oil, it's inevitable that some of this oil will be burned up in the combustion process. That's why a certain amount of oil consumption is perfectly normal. Ultra-low oil consumption indicates one of two things: either the oil film is too thin, or the oil is not reaching the critical upper portions of the cylinder walls where the compression rings reverse direction at top-dead- center (the so-called "ring-step area"). Without adequate lubrication, there's a high risk of metal-to-metal contact between the compression rings and the cylinder wall. Experience seems to indicate that oil consumption lower than about a quart in 20 hours may not bode well for long cylinder life. Barrel wear in the ring-step area becomes likely, leading to rapidly deteriorating compression and accelerating oil consumption at 500-1000 hours. While low oil consumption has always been acknowledged as a sign of a tight, well-broken-in engine, there is strong evidence that a quart in 30 or 40 hours may well be too much of a good thing. Edited May 19, 2019 by Shadrach 1 Quote Link to comment Share on other sites More sharing options...
David Lloyd Posted May 19, 2019 Report Share Posted May 19, 2019 I had three reman Continental engines (one at a time) not need a quart within the first 50 hours. Each started at 12 and wound up around 10 quarts. As time was put on each, oil consumption gradually increased from a quart in 20 hours to a quart in 8 hours. First reman went 2350 hours without any problem whatsoever. The next ate exhaust valves on a sad basis beginning at 550 hours. Many cylinders later I gave up at 1550 hours. Yes, it was a Continental reman, why do you ask? The last engine had 1250 hours without any problem whatsoever when the airplane was sold. Except for break-in, used Aeroshell 15W50, oil and filter were changed every 50 hours, about every 10 weeks. How many hours on your engine? 1 Quote Link to comment Share on other sites More sharing options...
carusoam Posted May 19, 2019 Report Share Posted May 19, 2019 +1 on Continental Using much less oil compared to Lycoming... 1) Less used... like a quart every 15-20hrs? 2) Less spread on the belly... 3) Near impossible to get valuable compression readings on... 4) Where oil hides... and how long it takes to come down to the oil pan... after a flight... Fun with Continentals... Best regards, -a- 1 Quote Link to comment Share on other sites More sharing options...
Gatlin Gun Posted May 20, 2019 Author Report Share Posted May 20, 2019 20 hours ago, lifendet said: How much hours since last oil change? I think like 15 hours...and it hasn't changed/dropped. Quote Link to comment Share on other sites More sharing options...
Gatlin Gun Posted May 20, 2019 Author Report Share Posted May 20, 2019 5 hours ago, Shadrach said: Experience seems to indicate that oil consumption lower than about a quart in 20 hours may not bode well for long cylinder life. Barrel wear in the ring-step area becomes likely, leading to rapidly deteriorating compression and accelerating oil consumption at 500-1000 hours. While low oil consumption has always been acknowledged as a sign of a tight, well-broken-in engine, there is strong evidence that a quart in 30 or 40 hours may well be too much of a good thing Yea, that was my concern EXACTLY. The motor is very very solid and has proven reliable with the last owner (proven by mx books; not just "testimony"), but the low oil has my attention. Engine monitor, oil temp, oil pressure...all seem, well....perfect. So, I'll keep monitoring. Thank you for the insight! Quote Link to comment Share on other sites More sharing options...
Gatlin Gun Posted May 20, 2019 Author Report Share Posted May 20, 2019 5 hours ago, David Lloyd said: I had three reman Continental engines (one at a time) not need a quart within the first 50 hours. Each started at 12 and wound up around 10 quarts. As time was put on each, oil consumption gradually increased from a quart in 20 hours to a quart in 8 hours. First reman went 2350 hours without any problem whatsoever. The next ate exhaust valves on a sad basis beginning at 550 hours. Many cylinders later I gave up at 1550 hours. Yes, it was a Continental reman, why do you ask? The last engine had 1250 hours without any problem whatsoever when the airplane was sold. Except for break-in, used Aeroshell 15W50, oil and filter were changed every 50 hours, about every 10 weeks. How many hours on your engine? That's actually good news to hear... My bird is a Rocket (continental 520) with 800 SMOH. And what I'm hearing from you and Carusoam, it sounds more normal (1qt per 20 hours) than abnormal, but I'll definitely watch it closely. Thank you! 1 Quote Link to comment Share on other sites More sharing options...
carusoam Posted May 20, 2019 Report Share Posted May 20, 2019 Maintaining CHT is what keeps the oil use down... Study up on the best ways of controlling TIT and CHTs for your engine... Hotter CHTs wear the inside cylinder surfaces where the oil ring glides.... as that gap wears it is more open to oil flow into the cylinder... Or fly it like a fire breathing dragon, and swap out cylinders as they wear... you get two choices with that... Its good to have choices. Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Gatlin Gun Posted May 20, 2019 Author Report Share Posted May 20, 2019 10 hours ago, ArtVandelay said: Do you have an air/oil separator? Tom Um.........not sure. Quote Link to comment Share on other sites More sharing options...
Gatlin Gun Posted May 20, 2019 Author Report Share Posted May 20, 2019 1 minute ago, carusoam said: Maintaining CHT is what keeps the oil use down... Study up on the best ways of controlling TIT and CHTs for your engine... And that's why I'm not toooooo concerned. I fly her gently; 65% power--and watching CHT and EGT very closely. CHT maintains in the low 300s with the power settings I'm using in climb and level-off. I feel confident I'm treating her like it's her Bday/Anniversary when I take her out, and it's only been like 10-15 hours, but I just wanted the experience on here to doublecheck my new-to-GA brain. Thank you, Carusoam. Quote Link to comment Share on other sites More sharing options...
carusoam Posted May 20, 2019 Report Share Posted May 20, 2019 Also, for your consideration... Look into the MAPA training... if you haven’t done any transition training lately... or want some follow up, or get to the next level of comfort.... MAPA has highly qualified CFIIs with Mooney specific training... including specific down to Rocket, Missile, and everything else... Ownership skills, maintenance skills, and IR flight skills, all get honed in a weekend... and dining and social skills too! Best regards, -a- 1 Quote Link to comment Share on other sites More sharing options...
Shadrach Posted May 20, 2019 Report Share Posted May 20, 2019 (edited) On 5/19/2019 at 5:58 PM, carusoam said: +1 on Continental Using much less oil compared to Lycoming... Any theories as to why? Same cylinder and piston materials, same combustion chamber shape, same honing process, same oils aporoved. No logical explanation. How much did your Lyc burn? I usually add 2qts between 50hr oil changes. I don’t find CHT has much affect on burn rate. Oil temp seems to affect it more. Edited June 4, 2019 by Shadrach 1 Quote Link to comment Share on other sites More sharing options...
carusoam Posted May 20, 2019 Report Share Posted May 20, 2019 Ross, That is the question of the day..! my O360 needed another quart in about 8-9 hours... until late in life, where it started to experience noticeable blow-by issues... exhaust smell in the oil, foamy oil, Usage increased as the oil got older... ie first 10hrs... took 10hrs to need a quart... mid 10hrs...took 9hrs to need a quart... last 10hrs need a quart sooner.... Long Xcountries used surprising less oil than short Xcountries... my M20C liked to vent oil and cover the belly... 1) might be as as simple as where the case vent is located... compared to climb angle.? Air oil sep owners would be telling us some great news about saving a quart every 20hours... 2) Or see what the oil control ring looks like from each supplier.? 3) oil viscosity at the oil control ring might give a hint... is that region noticeably hotter in a Lycoming? 4) LOP keeps the oil pretty clean, my O360 was only operated ROP... I have no insight for why or how this actually happens... PP thoughts only... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
chrisk Posted May 20, 2019 Report Share Posted May 20, 2019 A few thoughts The only aircraft engine I have seen that does not use quarts of oil between changes is a Rotax. If I fill my oil to max capacity, my engine consumes it quickly, and then deposits it on the belly of my Mooney. I now only fill to 6 quarts, instead of 8. But for long trips I still fill to 8 out of paranoia. Note: a rag soaked in 100LL works well for removing the oil from the belly, and there is even a convenient way to acquire more when you are under the plane. Oil consumption is slower when the oil is fresh (i.e. less per hour in the first 10 hours, more per hour in the last 10 hours). . When some one asks how many hours per quart, I truthfully say "I have no idea, most of it ends up on the belly". Quote Link to comment Share on other sites More sharing options...
PT20J Posted May 21, 2019 Report Share Posted May 21, 2019 All this oil discussion is really interesting. On another recent related thread, I noted that I have for 40 years run 4 cyl 320/360 Lycomings between 6 and 7 qts. (start at 7 and add a quart when it gets down to 6). This is based largely on the SOPs for various flight schools I've been associated with. I ran my '78 J this way -- it got around 4.5 hours/qt, but it had some oil seeps -- and I've been running the new IO-360-A3B6 in my '94 J this way. The new engine started out at about 7 hrs/qt and has been improving, though it's only got about 35 hours on it. and I've been keeping it close to home. I'm planning to see how it does on its first long trip when I go to MooneyMAX. It seems that many find a lot of oil on the belly when running more than 6 qts. I discussed this with my Lycoming field rep who has a lot of experience. Takeaways from this discussion: 1. Oil consumption depends on the installation as well as the engine. This makes sense. The breather is necessary to vent pressure and moisture from the crankcase. The venting process will naturally carry some oil oil out the breather. You can imagine that if the end of the breather is located in an area or relatively low pressure, then there will be more flow out the breather and more oil loss. 2. Older engines with excessive blow-by will vent more oil. 3. Higher oil level brings the oil closer to the breather that is located at the top rear of the engine and may result in increased oil consumption. Extended climbs do the same thing. 4. For many installations, the optimum oil level is between 5-6 qts. 5. Running much below 5 qts may result in higher oil temperature and lower pressure. I've noticed this on one occasion when the level got down to 4 qts. Based on this, after I'm pretty certain that the oil consumption has stabilized, I'll try running between 5-6 and see how that compares to running between 6-7 qts. As others have noted, I've also observed that oil consumption is greater for the same engine time if the legs are short versus longer. I think this is likely because the airplane spends more time with colder temps (more takeoffs) which causes greater clearances and more oil gets past the rings and also it spends more time in climb at higher power which also pumps more oil. Skip 2 1 Quote Link to comment Share on other sites More sharing options...
Gatlin Gun Posted May 21, 2019 Author Report Share Posted May 21, 2019 2 hours ago, PT20J said: Based on this, after I'm pretty certain that the oil consumption has stabilized, I'll try running between 5-6 and see how that compares to running between 6-7 qts. Skip, that was an awesome summary. Thank you for that insight. I think my takeaway is it all just depends. My Continental engine is solid, it holds temperatures of CHT/EGT very well, and I just need to watch it. It might be awesome or it might be an issue, but it seems it depends from motor to motor, and powerplants simply differ. So, I will be vigilant, but at this point, it's too early to tell. Thank you! Quote Link to comment Share on other sites More sharing options...
Gatlin Gun Posted May 21, 2019 Author Report Share Posted May 21, 2019 Hope to see you all at Mooney Max next month!! Quote Link to comment Share on other sites More sharing options...
FloridaMan Posted May 22, 2019 Report Share Posted May 22, 2019 My rocket’s oil consumption is also pretty low. A lot lower than any lycoming I’ve flown. Quote Link to comment Share on other sites More sharing options...
Gatlin Gun Posted June 3, 2019 Author Report Share Posted June 3, 2019 On 5/21/2019 at 7:29 PM, FloridaMan said: My rocket’s oil consumption is also pretty low. A lot lower than any lycoming I’ve flown. Can I ask "how low" is pretty low? As I went back into my logbook, I've flown less hours than I thought...which is bad for sanity but good relative for this conversation. Still, it's at the forefront and top on my "watch list". Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted June 3, 2019 Report Share Posted June 3, 2019 My engine has very low oil consumption. It often goes 25 hours without needing any oil. Quote Link to comment Share on other sites More sharing options...
M20F Posted June 4, 2019 Report Share Posted June 4, 2019 On 5/20/2019 at 2:49 PM, chrisk said: If I fill my oil to max capacity, my engine consumes it quickly, and then deposits it on the belly of my Mooney. I now only fill to 6 quarts, instead of 8. But for long trips I still fill to 8 out of paranoia. Note: a rag soaked in 100LL works well for removing the oil from the belly, and there is even a convenient way to acquire more when you are under the plane. The 8 is for certification purposes somebody can post the exact math but essentially to make it work 8 is the number that leads to the right minimum available oil. The real answer is 6 on the dipstick (generally 7 added to read 6 if you change filter), anything else you might as well just pour on the ground (or rub on yours and the planes belly). 8 is the number that just works for the cert, no other purpose and the engine doesn’t actually work with 8. Mike Busch has a lot of really good articles on the topic. All basically FUD. Quote Link to comment Share on other sites More sharing options...
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