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Oil On My Belly

Sikorsky

Registered User
My experience is they are not worth the metal they are made with, but others may disagree...

sj
 
I would try and find the issue of the excessive blow by first, not sure with the C90’s but there is a modification to the breather line elbow on the crank case, it consists of brazing a three inch long tube with a slight angle cut. Seems to help on the other small Continentals from throwing oil out the breather, even with good piston rings.
 
Experimental J3, Rolls Royce Engine, for a mental picture, the engine is very similar to a Continental C90. Oil from the breather tube, not a lot but a bit and considering a crank case vacuum and oil separator from Anti Splat Aero.

https://antisplataero.com/products/the-asa-oil-separator

and

https://antisplataero.com/products/crankcase-vacuum-kit-complete

Does anybody have any experience with these or am I just adding more weight and complexity?

Opinions?

Zach

What oil level are you running

Glenn
 
I’m having trouble picturing the 3” long tube with an angle cut. Actually I can picture it but don’t know how shortening the tube will help. I have a 2-3 foot line going to the vent and then venting out the bottom of the cowl. The build was extensive with new everything with proper brake in procedures in 50-60 degree weather.
 
I have a 6 qt kidney tank and have run 6, 5, and 4.5 for a beta test.

I never run more than 3.25 qts, add when it gets to 2.5. Try 3 qts and see if it stops.
Also, don't trust marks on stick, add a qt at a time and check against stick marks

Glenn
 
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You probably want that ugly oil/water mix to go overboard and cause global warming. Having cleaned a few of those tubes, I don't want any part of that back inside my engine. Looks like σκατα.
 
I built a wood fire in the house today, warming is happening! I probably shouldn’t worry about the small breather tube issue as the smoke system will be going on soon and the belly will soon be BATHED in oil, but I like making stuff more difficult than it has to be.

I wonder if there is a correlation between high compression continentals and breather tube oil issues.
 
I’m having trouble picturing the 3” long tube with an angle cut. Actually I can picture it but don’t know how shortening the tube will help. I have a 2-3 foot line going to the vent and then venting out the bottom of the cowl. The build was extensive with new everything with proper brake in procedures in 50-60 degree weather.

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I'm wondering.........how much case pressure in small engines? Depend on blow-by? I'm assuming that case pressure is not necessary and robs horsepower. Would a larger case vent decrease pressure and therefore reduce the vent pressure.......say a 1" or greater case vent vs. the 3/8-1/2" ?
 
I have the crankcase vacuum and oil separator on my IO-390. It works great. There was a thread this spring where I tested crankcase pressure using the vacuum and without. It works as advertised. I’ve never had a drip of oil from the Cub on the hangar floor.
 
Oh… now THERE is a damn good idea. I know for a fact my vent doesn’t have that little beauty on in. And venting it over the top is also a a good idea. Maybe not for winter ops but summer I don’t see an issue with that freezing and plugging up.

Bet that 3 inch tube will fix the problem 100%.
 
ike they have said above the extension and over the top really helps. and as Glenn said the matings on some of the sticks are way off. I like 4 qts have more issues with leaks than blown out oil.
 
I have an 85 that i recently put new cyl and broke in, had been fine for 50 hrs, not using much, but put the long breather elbow and its blowing a qt out every 2 hr. 3 qts max in the sump. Compression didnt show any low cyl. Not sure what changed. Just swapped the elbow back and going to see. put a baby bottle on the end of the breather to see how much its pushing out
 
I have an 85 that i recently put new cyl and broke in, had been fine for 50 hrs, not using much, but put the long breather elbow and its blowing a qt out every 2 hr. 3 qts max in the sump. Compression didnt show any low cyl. Not sure what changed. Just swapped the elbow back and going to see. put a baby bottle on the end of the breather to see how much its pushing out
Where is the oil coming out? The breather? The exhaust? A compression test will not show a bad oil control ring.
 
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