Les Holman Oil breather separator

[Bob Wood]

Les
I did not get a chance to ask you about your oil separator at Oshkosh. I am  running Scott Casler's breather and getting some mist on my fuse belly. Can you describe your Coors can system.  It looks like a collector that has to be checked periodically. I get very little seems like a good fix.
Thanks
Bob

[flyover1974]

Hi, im not Les Homan but i take the same principle on my engine:
you need only a cap that can hold inside a metal sponge (don`t know the word for...but this you use to clean pot or pans)
and a screen between the engine and the cap so no pieces of the sponge goes inside the engine.
The oil vapor goes trough this breather and condense on the sponge so only the air go out of the breather and the condensed oil drop back inside the engine.
This work very well.
I used a piece of 2x2 inch aluminum tube, weld a flat cap on the upper side with a 1/2 inch hole in the middle, on lower side weld a flat square with 1,5 inch hole in the middle and bore the fastener screw hole on the corner.
Inside the metal sponge and between this cap and the engine is the flat pressed tea screen.
see here, the last pic you can see the breather very good: thread of my engine
Down here a pic of that piece just after welding without the hole on top.

hope my explanation is good to understand.
cheers Hermann the italian

[BobSeverance]

I take the oil vent and inject it into my exhaust and it burns it up and throws it out the pipe....

[flyover1974]

I take the oil vent and inject it into my exhaust and it burns it up and throws it out the pipe....

This way is for sure the simplest one but on a 2 opposed cylinder engine is it not the best idea:
What do you think...how much air is pushed out the vent when bdc is reached?
Exactly the volume of the engine size, in my case its 1200ccm, also more then one liter of air and oil mist. (In practise it is less then the displacement but thats not the interesting point.)
Anyway the same air is sucked inside the engine breather back when the pistons reach tdc.
So...if the vent is connected by a hose to the exhaust, hot exhaust burnt gases goes back in the engine case every revolution...
That is for sure not what i want in my engine.
The second reason is that some engine burns a lot of oil if is not recovered and not everyone is willing to refill lost oil every time before you fly.
And if that oil is not recovered in some engine is a considerably amount per hour
Cheers

[Dan_]

If the Cassler oil breather is the same as Morry Hummel's it is much more sophisticated than the Brillo pad type catch can.

The Hummel crank case breather works with a set  flapper valves controlling air movement through appropriate sized holes to keep a negative pressure on the inside of the case.

In other words the valve lets air out but not in, by means of how it is timed compared to the pumping action of the pistons. 


Harleys have more CCs and much more stroke, and use the same type system. 


Google Hayden Krank Vent.


If the Hummel breather is belching oil, perhaps you have too much oil in the engine or something is not sealed well.

[leshoman]

The breather i built has reed valve in inside to create negative pressure on crankcase.  Very little oil loss unless there is to much oil in engine. I have experienced this a couple times when i added oil after flying for a while and thinking it was a little low.  It throws it out from places where it was not leaking before.

[CHARLES DEBOER]

Les, Bob Wood wants to know about the coors can recovery set-up.  I believe you had a coke can mounted on the outside with the crank case breather tube inserted into it.  I am also interested in that can mounted to catch to blow-by coming out of my Casler engine.

[leshoman]

I have a diet coke alum bottle shaped can zip tied to engine with blow by oil line routed into it. Had to drill a hole in top of can to let air pressure out

[CHARLES DEBOER]

do you have any photos on one of your walk around videos?

[Bob Wood]

Les,
I duplicated your idea with a Red Bull small can.  Put a grommet in the top and an aluminum tube with holes in the bottom sides and some holes drilled in upper half of the can to let pressure out. The top of the aluminum tube just plugs into the tube coming out of the Cassler breather.  I had a very small amount of blow by collecting on landing gear, seems to be a good solution.  I will take pics and post on here this week.

Thanks,
Bob

[flyover1974]

Sorry guys...didn't know you speaking about some more sophisticated breather.
Very interesting

[leshoman]

Couple of pictures of catch can, any light weight can will work, just something catch a small bit of oil.

[flyover1974]

Les,

A question off topic: what material are this brass color caps in the unused pushrod holes on the second picture?
And how they are fixed?
On my engine i tryed to hammer in caps from a tractor engine (found with the right diameter) but don't work really well because all 4 leaked...
Now i use a piece of 1/16 thick aluminum fixed with a center screw between the two holes. This piece press on the pushrod tube seals, its now dry but i don't like this solution...is not very nice.

[leshoman]

Those are aluminum plugs Scott Cassler at Hummel Engine installs,

[s johnson]

Here are  a few pictures of my new breather tube catch container. It's a pill bottle with the cap drilled which is a screw tube cap. The hose just slides in kind of tight. I drilled holes around the top of the bottle so the bottle will not pressurize. I had a aluminum strap out of a 1/16" thick 1/2" wide aluminum strip. Then just screwed in into one of the tapped holes on the bottom side of the case. The breather is a modified Joe Engleman style Breather assembly.

Scott J.
Oshkosh