Switching oils and oil consumption

RV8Squaz · #1 06-05-2007, 02:03 PM

Hey Guys,
I now have about 80 hrs on my engine and RV-8. The engine is a freshly overhauled angle valve IO-360. During break-in, I used Aeroshell 100 mineral oil. During my first 25 hrs, oil consumption appeared to be about 1 qt per 8 hrs. I did an oil change and ran Aeroshell 100 again for the next 25 hrs. Oil consumption remained at 1 qt per 8 hrs. I changed the oil at 55 hrs and switched to Aeroshell 100W Plus. My oil consumption increased to 1 qt per 5 hrs and has remained that way since. I know "high oil consumption" is a relative term, but what gives? I didn't expect the increase in oil consumption just from switching oils. I know I'm not throwing it out. My belly, firewall, and cowl are clean. The air/oil separator that is part of my inverted oil system is very effective. Any of you guys have a similar experience?

I know can't run mineral oil forever, but I'm thinking about switching back to it for the next oil change just to see if there are any changes. I'm also curious if 15W-50 would have any affect.

Thanks,
Jerry

KirkGrovesRV8 · #2 06-05-2007, 03:52 PM

For what its worth, when I switched to AD oil I went with 15W50 aeroshell and burn about 1qt every 10-12hrs.

JonJay · #3 06-05-2007, 03:52 PM

My IO360 has only thirty hours on it and I am still running mineral oil. It is an Aerosport Power Engine and it throws up out of the breather anything more than about 6 1/2 - 7 qtz. Bart told me that was pretty normal.
You can smell the oil burning off on the exhaust as my breather directly outputs there for that purpose.
If I let it find its own level somewhere between 6 - 7 quartz, my oil consumption is much less than a quart per 8 hours, maybe 1/2 quart per ten hours or so.
So, I simply do not put the extra oil in it. Not sure if you are filling to 8 quartz or not. Just a thought.
Good luck.

RV6_flyer · #4 06-05-2007, 03:59 PM

Quote:

Originally Posted by JonJay

My IO360 has only thirty hours on it and I am still running mineral oil. It is an Aerosport Power Engine and it throws up out of the breather anything more than about 6 1/2 - 7 qtz. Bart told me that was pretty normal.
You can smell the oil burning off on the exhaust as my breather directly outputs there for that purpose.
If I let it find its own level somewhere between 6 - 7 quartz, my oil consumption is much less than a quart per 8 hours, maybe 1/2 quart per ten hours or so.
So, I simply do not put the extra oil in it. Not sure if you are filling to 8 quartz or not. Just a thought.
Good luck.

My experience is the same as this post.

What kind of cylinders is Jerry using? CHROME cylinders will use a LOT more oil than the Nitrite or steel cylinders.

My steel cylinders use about 1 quart every 6 or 7 hours. I have over 2,000 hours on my RV / engine. Was down around 1 quart every 25 hours when it was only 25 hours through 400 hours.

robertahegy · #5 06-05-2007, 05:19 PM

I have a factory new Lycoming 0-360 A1A from Van's. I broke it in using Aeroshell 100, changing it at 1 hr, 25 hrs, then 50 hrs, all changes with new filters. I changed the oil at one hour to get rid of any machine particulate and preservation oil not drained in initial draining. I was using about 1 qt in 14 hrs. When I switched to 15W50 Aeroshell, my consumption dropped to about 1 qt in 20-22 hrs. I change oil and filter at 25 hrs so I haven't had the need to add. I put in 8 qts with the new filter. The level drops to about 7 quarts (maybe slightly higher) after running up to check the filter. The level reaches the 6 quart mark at about 25 hrs. I get very little oil residue on the belly of my plane.

Roberta

osxuser · #6 06-05-2007, 05:20 PM

Yeah, I used Mineral until 50 HR's, then switched, it's hard to tell what gives, but leave mineral in it awhile longer would be my suggestion. We have new Superior Cylinders.

RV8Squaz · #7 06-05-2007, 06:02 PM

Thanks for all the quick replies. I have Cerminil cylinders and was told they break in very easy. I did all the proper stuff during break in. The oil consumption quickly stabilized at 8 hrs/qt. The oil consumption didn't change until I switched oils. In any case, even at 8 hrs/qt, it sounds like I have a lot higher oil consumption than the rest of you.

Jerry

Ironflight · #8 06-05-2007, 08:19 PM

Hi Jerry - I have cerminil like you, and I get 7-8 hours to the quart. I am beginning to think that the Cerminils just don't get the same level of oil usage as other treatments....but the engine is doing just fine!

Paul

Russ McCutcheon · #9 06-05-2007, 08:34 PM

I have the same cylinders you have, Lycoming angle valve 200hp. Does every body posting have the same cylinders or are we comparing apples to oranges? I just did a very major overhaul about a year and a half ago and installed brand new Lycoming cylinder kits, we did nothing special just installed them as they came, there nitrite by the way. After 50 hours of Aero Shell 100 it was steady at one quart in eight hours, I then started using Aero Shell 15-50 and it stayed the same but has slowly gotten even better to an average of one in 9 to 10 hours, I think it?s at about 300 hours now. Some one did a poll on hear a wile back for this cylinder type Lycoming and I think the average was between 8 and 12 hours per quart.

I vote you dump that oil out and put back mineral oil, if it comes back then next time go for 15-50 if it does not come back then you might have a problem like ring gaps stuck lined up or something, other then this you need the pros to help.

zav6a · #10 06-05-2007, 09:43 PM

I ended up with poor seating on a set of rings and the oil would darken to near black very quickly - litterally within a few hours -even though it was only burning a quart every five or six hours. Compression was great.

Although it is ok to tolerate consumption, you should not tolerate blowby that is contaminating oil. It will show up as premature wear on moving parts and higher levels of corrosion.

New rings, hone and 10 hours of hard running with mineral cured it. Now still nearly the color of new oil when oil has been in 25 hours.