I am 12 hours into a factory reman engine on my 1958 PA24-250. The engine is running great but is blowing oil out through the Air Wolf air/oil separator. The mechanic has checked the "plumbing" and it looks to spec. I also installed the dual stainless exhaust a few years ago. Could that affect the location of the drain? I have a wet vacuum pump that is connected to the separator. Ideas?

Tom,

Welcome to the ICS Maintenance Forum. I see this is your first post here.

You might search in the upper right on past postings on this subject. One that may parallel your situation is this one viewtopic.php?f=95&t=7073&p=56436&hilit=oil+consumption#p56436

Obviously different engines but may provide some insight. Please post any progress so we can all learn. Thanks.

Hi Tom,

My experience is that air/oil separators are more trouble than they are worth and may in some cases be counter productive to long engine life.

Without an an air/oil separator, my io540 will in short order blow out any oil above 8 qts and once down to 8 qts it will more slowly blow oil out until around 7 qts where it stops. So, at each oil change I put in 9 qts, the filter takes 1/2 a qt. and in roughly 15-20 hrs the engine deposits a quart and 1/2 on the belly. I usually change the oil at 30-35 hrs and it sits right at 7 when I do. I have discussed this at length with my IA because my partner(bride) will start adding oil at 8 qts if I'm not around. The advice I got was to monitor the oil temp as I allowed the oil level to go down and if there was a change(higher) to add oil at that point. There was no increase in oil temp at 7 qts.

The compromise I worked out with the bride is that in the cool months we will run at 7 qts. and in the warm months 8 qts. I think I had some sway as I'm the one who cleans the belly.

Hope this helps, Don

Tom, the previous advice on keeping the oil levels at the engines "happy" level, in your case at 9 quarts will keep the blow- by lessened if not contained completely ( maybe less as in Don's case, but I would start at 9 quarts first). Another thing is your rings probably haven't totally seated yet and until they do you will get more than normal blowby, exasperating the oil mess at the higher oil quantities in the sump.So just keep the oil at 9 quarts and keep flying at 75% power until the oil consumption stabilizes. You will have a hard time to confirm that it has stabilized if you are blowing oil out the breather.
Good luck,
Gary

Tom,
Lycomings don't like full oil quantities.
Chances are, at your hours, your engine is broken in and ready for a long and happy service life.
Let your oil level go down until it just doesn't drop anymore, probably around 7 qts. or so, and then watch it STAY THERE.
This is your engine's happy level and only add when it drops 1 qt. below that level (I would bet that it won't use another qt.
before oil change time}.
Quit worrying and micromanaging and enjoy your new Lycoming.
Steen
PS the min. oil level of safe ops for your engine is....from memory.....around 2-3 qts. so long as oil pressure/temps remain normal.

I get that the O-540 probably doesn't "like" to run at 10 quarts. However, on a 4 hour trip we started at 10 put 1 quart in half way, but still ended at 8.
So my concern is the RATE at which it "wants" to get down. I will try running some short trips to see if it ventures below 8, but if anyone has any other ideas please let me know.

Reread previous info re 7qt. limits. You have not yet gotten there. You have plenty of room for experimentation before
you enter any danger levels, so watch youR il temps and fly the engine down to it's happy oil level. 7-8 is probably in the range of
happy. If it drops below 6qts. rapidly, you have a problem....otherwise you have a great and happy Lycoming,IMHO.
Steen
ps....LET US ALL KNOW.

Tom,

You likely have received the ICS newsletter and its nice article from Mike Busch about oil. I don't subscribe to all his recommendations but sure learned some more about what the FAA requires for oil capacity in this one. If you haven't gotten the newsletter, I'll forward you a copy and then you'll have the email address to be added.

I agree with the above posts on oil levels. could you give us some details on the break-in. Power settings, CHT's, Cylinder type, break in oil, etc. All of these can effect break in and time to break in.

Jim,
I can only relay my experiences with Lycomings.
I only use Lycoming new cylinders so I have no experience with other types.
I do a short (2-4min.} runup to maybe magcheck rpm for a bit, then shut down for a leak check.
If all is well, I fly it at low altitude....below 4000'....at 75% power, wide circles around the airport, keeping the cyl. head temps and
oil temps below max with full rich mixture until the oil temps fall back. Usually,,,,,my experience.,.. about 40 min. and the cylinders
and rings are seated! The oil temps fall back rapidly when the rings seat.....you will know it if watching.
After that, fly it regularly and keep the oil clean and it will give you reliable service for a long time.
Steen

That is about the way I run a break in, usually with good results like you described in your post. I use the highest power setting that does not overheat the cylinders.

Thank you all for your feedback, but we found the issue. We replaced the old "wet" vacuum pump with an new dry model.
Oil consumption has stopped. 7 hours without adding oil and nothing coming from the separator. With a new factory reman engine that has been ported and balanced we are consistently at 190 mph at 11,500 ft with the throttle back 1/2". The wet vac pump was the villan!!!

Tom,

So glad to hear you got to the bottom of the oil loss. That sure is a new one for me.

Glad to hear it.
I guess they are called "wet" for a reason, eh?
Steen