significant oil leaks after adding oil-air separator

[Bryan Cotton]

bryan: the only air restriction left in my removed separator is the aluminum plate with about 15 1/8" holes in it. is that where you are at?

Yes - except I bored out the inlet and added a swirly tube.


I may have opened up some of the other passages. I don't remember.
viewtopic.php?f=7&t=4030&start=100

Edit: as stated the scrubber pads have been removed.

[Onex107]

I made my own oil/air separator out of a wide mouth one pint "Ball" jar. The Ball jar lid is a two piece that allows the outer part to be unscrewed from the jar without rotating the center of the lid. I put the breather tube through the center of the center piece, surrounded by six holes to allow the jar to vent out the top. A stainless scrubber under the lid helped condense the oil. The jar is marked in ounces so I could measure and record the blowby oil volume. It was mounted on the firewall with a large hose clamp allowing me to loosen the hose clamp, loosen the jar outer ring, and remove the jar to measure and empty the oil. The oil usage of the Aerovee was amazing compared to my Cont. O-200. The O-200 lost the first quart in the first few hours and a quart in 10 was considered normal, where the Aerovee only vented 10 to 12 ounces in 25 hours. I don't believe it is a good idea to return these vapors to the crankcase, and It is another way to measure the condition of the cylinders in addition to the compression check. I can supply a picture by email if you are interested.
( flyvfr@comcast.net )
Onex107 ( N2107X )
Don't tell anyone, but I installed this unit on my Cessna to test it before I built the Onex and a glass jar doesn't bother me either. My 40 year old Cessna had a glass gasculator, approved by the FAA, that never had a problem.

[funflyingguy]

i do appreciate the feedback. thank you.

(FYI: my recent oil loss was much more than even your continental engine and was all over the cowl and canopy. seemed to start with the backpressure caused by my unaltered air-oil separator. repair in progress i guess..)

jim

[Area 51%]

I had a maddening oil leak that seemed to originate from the hub, but what I discovered after making dams to identify the source, was the radius on the oil pump where the mounting flange meets the pump body was too large and wouldn't let the flange sit tight against the case. High pressure oil was being ejected past the gasket and accumulating everywhere except the point of failure.

A second gasket stopped the flow of oil to the outside of the engine but was an unacceptable long-term fix. A different pump with a smaller radius solved the issue. It is possible, however, the chamfer on the engine case might have been to blame. .

[pappas]

The Anti-Splat Vacuum kit might be able to be used with another separator. It would be worth a phone call to Allen at Anti-Splat to ask that question.

My experience is that he returns phone calls promptly and is completely willing to answer any questions you may have no matter how long the phone call lasts. He has a lot of knowledge. He doesn't try to sell anything but will give you an honest opinion.

Tell him what you have and ask if the vacuum kit might work with your equipment. The worst he could say is no!

[bvolcko38]

That bronze thing is definitely a restriction. I took mine out right away. I did some other mods to try and maximize flow and to get the flow moving down and spiraling around the inside of the can. Not long ago I removed the stainless scrubber pads. They looked fine but seemed to have gunked up a bit and I was leaking oil from the crank exit in the front. You definitely need to eliminate back pressure there.

I drilled (8) 1/8" holes in "the bronze thing" in 3 differnt stages, no more leaks or back pressure

[Bryan Cotton]

I drilled (8) 1/8" holes in "the bronze thing" in 3 differnt stages, no more leaks or back pressure

The bronze thing can be seen in the background of this picture. It threaded into the exit hole and I think David made the observation that it would be likely to get oil soaked and become a significant restriction.

[funflyingguy]

so... after a couple of weeks of cleaning, tightening, torquing, runups and 2 very short test flights (and a vacation thrown in...), it appears my engine oil leaks were caused by:
1) too much oil in the crank case, 2) a mis-calibrated oil dipstick, 3) too much back pressure initially with my new air-oil separator, and... a very loose fitting oil dip stick.

#1 was caused mostly by # 2 and has been corrected now that i know. i have a new dipstick on order from sonex to calibrate it correctly.

the air-oil separator has been pretty much gutted and drilled out for a much freer flow, but will not be re-installed until all other oil-related issues are resolved.

the last thing i found is that my oil dipstick comes loose every time i run the engine. the last 2 times i noticed serious oil leaking out of it and down on various things below it. at first, i was blaming the front-most pushrod tubes, which is where most of the oil was showing. but later, after a much more thorough cleaning of the the front half of the engine, that doesnt seem to be the case. while flying, it seems to be blown along the front upper and front lower seems of my cowling halves and just around the very front areas of the engine. as a test, i asked a friend to monitor the front of the engine while i gently blew air back up into the breather tube. i had removed the oil dipstick for this test. interestingly, i got a very slight amount of oil bubbling out around the prop extension where it meets the block. but more importantly and a bit scary, i got a large gusher of oil out the oil dipstick tube. cleaned it all up, reinserted the oil dipstick and had my friend do the gentle blowing into the engine breather tube. same slight bubbling at the rear of the prop extension but still a smaller, but steady few drips of oil out from under the dipstick cap which was on as tight as i could get it. looking at the inside of the dipstick cap, i see what appears to be an O-ring but is a bit chewed up. is the O-ring replaceable?

question: i have studied the 'build' manual and videos from sonex for the building of this engine. it appears there is only an oil slinger at the front of the crankshaft to keep the oil in. is this true? if the engine was run with too much oil for a brief period, can the slinger be damaged?

i might add: along the way i got concerned about the oil pressure readings i was getting at all operating temps. so i removed and thoroughly cleaned the 2 oil pressure relief valves. both seemed to be sticking slightly initially, but arent now. the pressures dropped on average about 10 - 20PSI. still my oil pressure readings seems high. so i ordered a new oil pressure sender from sonex.

FYI: i have an MGL enigma that seems to be working just fine, giving me the oil pressures and temps. no known issues with it or the RDAC.

thanks all.......

[Bryan Cotton]

I doubt you will damage the slinger. It's just machined features on the crank.

I'm not a big fan of the Sonex dipstick. Mainly because I could not seem to get consistent readings with it. Others seem to have no issue. So you can see what I did on page 2 of this thread:
viewtopic.php?f=7&t=6894

Before I replaced the Sonex dipstick, I think I had a strip of the good duct tape jammed in there because it was loose.

[funflyingguy]

thats some work you did for this. great to have those pictures. i just ordered the same thing; thanks.

do you know if anyone has devised a dipstick-like contraption for the other side where the oil is added at? .... or would the crankshaft, etc be in the way?

should i find that the (high) oil pressures i am seeing are correct, are there weaker oil pressure relief valve springs out there somewhere? (FYI... at normal flight temps, i am seeing oil pressures between 80 and 95 PSI....)