Eagler's Nest

Engines => 2 Cylinder => 1/2 vw => Topic started by: Bob Wood on August 09, 2017, 07:13:15 AM

Title: Les Holman Oil breather separator
Post by: Bob Wood on August 09, 2017, 07:13:15 AM

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

Title: Re: Les Holman Oil breather separator
Post by: flyover1974 on September 03, 2017, 09:27:38 AM

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 (https://www.eaglersnest.com/forum/index.php?topic=1558.msg8770#msg8770)
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

Title: Re: Les Holman Oil breather separator
Post by: BobSeverance on September 03, 2017, 03:29:05 PM

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

Title: Re: Les Holman Oil breather separator
Post by: flyover1974 on September 04, 2017, 04:31:58 PM

Quote from: BobSeverance on September 03, 2017, 03:29:05 PM

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

Title: Re: Les Holman Oil breather separator
Post by: Dan_ on September 04, 2017, 06:04:34 PM

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.

Title: Re: Les Holman Oil breather separator
Post by: leshoman on September 06, 2017, 01:05:27 PM

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.

Title: Re: Les Holman Oil breather separator
Post by: CHARLES DEBOER on September 06, 2017, 04:57:40 PM

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.

Title: Re: Les Holman Oil breather separator
Post by: leshoman on September 06, 2017, 06:02:00 PM

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

Title: Re: Les Holman Oil breather separator
Post by: CHARLES DEBOER on September 06, 2017, 09:03:27 PM

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

Title: Re: Les Holman Oil breather separator
Post by: Bob Wood on September 07, 2017, 07:21:35 AM

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

Title: Re: Les Holman Oil breather separator
Post by: flyover1974 on September 07, 2017, 11:57:18 AM

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

Title: Re: Les Holman Oil breather separator
Post by: leshoman on September 07, 2017, 02:47:29 PM

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

Title: Re: Les Holman Oil breather separator
Post by: flyover1974 on September 07, 2017, 04:00:35 PM

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.

Title: Re: Les Holman Oil breather separator
Post by: leshoman on September 07, 2017, 04:09:26 PM

Those are aluminum plugs Scott Cassler at Hummel Engine installs,

Title: Re: Les Holman Oil breather separator
Post by: s johnson on September 10, 2017, 02:49:14 PM

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

Title: Re: Les Holman Oil breather separator
Post by: s johnson on September 10, 2017, 02:52:08 PM

Sorry I posted one of the pictures twice. Here is the other picture.

Scott

Title: Re: Les Holman Oil breather separator
Post by: Bob Wood on October 10, 2017, 01:46:07 PM

Here is my Red Bull separator. Drilled aluminum tube thru a grommet to keep it tight.  Holes drilled in the bottom of the tube and thru the can midway up the side.
Not a drop anywhere anymore.

Bob

Title: Oil breather separator
Post by: BobSeverance on October 10, 2017, 03:06:07 PM

flyover1974: I also have a reed valve on my engine to keep negative pressure in my engine therefore eliminating any of the exhaust gasses from entering my engine. Much like every other 2 cyl boxer modified VW engine. Some pressure is always in that tube never any exhaust.

Title: Re: Les Holman Oil breather separator
Post by: Mark Kramer on July 31, 2020, 04:55:47 PM

Well, even though this discussion is a little old, it is a current problem for me. I have a 1992 Mosler cb40. Mosler case, not vw. Have original paperwork from when it was test run at factory. It has a 1 inch hole in the top where a breather should be, I think. No threaded holes for bolts. Also was not drilled for a dip stick. I think it was supposed to have some kind of breather/filler combo I’ve read about, but I have never seen one if it exists. No matter what I have tried, I get a lot of oil along with the crankcase pressure out of the hole. The engine case is only supposed to have 1.25 quarts oil inside, with this small amount,I feel a loss of any is unacceptable. My last attempt was a check valve in the hole at the top, with a hose to a vented separator, draining out the bottom thru a hose to the rear bottom of the crankcase. Within one minute of running, there was oil pushing out of the air filter on top of the catch/separator can. There’s got to be an easier way to vent the crank case without losing oil.
Any ideas?
Thanks Mark

Title: Re: Les Holman Oil breather separator
Post by: leshoman on July 31, 2020, 05:02:28 PM

​on the 1/2VW engine i had there was a reed valve that would let air out of crankcase but no air back in.  Air leaving went to catch can and in a years flying i might have a couple thimble fulls of oils 

Title: Re: Les Holman Oil breather separator
Post by: Mark Kramer on July 31, 2020, 06:35:19 PM

Hi Les, I don’t have any bolt holes to install a reed valve assembly. I have a check valve there which only allows pressure out, nothing back in. From there to a catch can which is vented to the outside. From the bottom of the can a hose back to the crankcase at the very bottom. ( an attempt to put the captured oil back in). Oil gushes out of the vent on top of the can. Does the reed valve do something that the check valve doesn’t?
Love your videos Les... keep em coming.
Mark

Title: Re: Les Holman Oil breather separator
Post by: leshoman on July 31, 2020, 07:28:57 PM

You may have something else going on with your engine

Title: Re: Les Holman Oil breather separator
Post by: Tom XL-7 on August 01, 2020, 02:16:47 PM

The hose returning oil to the crankcase would need a check valve stopping oil from traveling out of the crankcase. On a 1/2 vw the entire crankcase changes pressure with piston movement sucking or blowing. If that line is below oil level your pumping oil out. Most of the stuff I have seen in a catch can I wouldn't want to return.  Remove the return to see if it solves your problem.

Title: Re: Les Holman Oil breather separator
Post by: Mark Kramer on August 01, 2020, 03:06:43 PM

Hey Tom,
I am going to do away with the oil return to crankcase. The last time I ran it with a check valve in the top of the engine, to a hose into a soda bottle, it spewed out a good inch into the bottle. The capacity is 1.25 qts in the crank case. I feel like I can’t afford that much oil coming out, hence my efforts to let it flow back in. I do not have what ever it had for a pcv valve. Also there are no bolt holes on top next to the blow by hole. So I cannot simply bolt on a vw style breather. I am certain I will come up with something. My biggest question right now is whether or not I need a check valve at the breather hole. Doesn’t blow by mean that the crank case can have only positive pressure? If so ,why the check valve? Maybe there are low pressure pulses in between highs. I’m planning on a simple can with the scrubbie stuff inside right on top of the  hole on top of the engine, with a breather filter on the top.
Any thoughts?
Mark

Title: Re: Les Holman Oil breather separator
Post by: Tom XL-7 on August 02, 2020, 07:09:31 AM

On a two-cylinder horizontally opposed engine we have two pistons either traveling outward or inwards together. This changes the crankcase volume decreasing on the inward and increasing on the outward travel. The change is equal to the bore and stoke times two. On the 4cylinder two of them travel in the opposite direction so volume stays constant. But we have removed the volume balancing pair. Thus the blow and the suck. The reed or check valves are installed to let the air out but not so readily back in thus running some negative pressure on one of the strokes and the high-pressure stroke just put things back at normal. It is not good to let air back in as it carries moisture and perhaps dirt. So an open breather would simply throw oil mist air at you and then pull outside air back in.  An oily mess as well as constant loss

Title: Re: Les Holman Oil breather separator
Post by: Mark Kramer on August 02, 2020, 02:53:49 PM

Ok, I hear ya. So with a check valve or reed valve there will be negative pressure and positive pressure pulses? And the one way valve stops pressure build up, and stops contaminates from entering. My issue with this engine is that an excessive amount of oil comes out of this hole with the pressure. Engine sump only holds 1.25 guarts. Can’t afford to lose any. Some how got to stop oil from coming out while allowing the pressure out.

Title: Re: Les Holman Oil breather separator
Post by: Dan_ on August 02, 2020, 08:40:04 PM

Your mission --should you decide to accept it is to cover said hole with the hummel reed valve (https://www.hummelengines.com/price-list) setup, plug the hole and make a new one that fits the hummel reed valve setup or plumb a line from said hole to a remote location with the hummel reed valve set up.

Harley and Beemer bikes use similar means, but are required by emission standards to return the crankcase fumes to the air filter to be burnt.  Google Harley crankcase ventilation. (https://www.google.com/search?client=firefox-b-1-d&sxsrf=ALeKk01O4SK0jW7fVIIq4poUYKPUqHg1iw%3A1596340545508&ei=QTkmX9nKHpuUtAaEyLfQCQ&q=how+harley+davidson+crankcase+breather+works&oq=how+harley+davidcrankcase+breather+works&gs_lcp=CgZwc3ktYWIQARgAMgQIIRAKOgcIABBHELADOgcIIxCwAhAnUJlDWP5nYOh2aAJwAHgAgAF1iAGBCpIBBDIuMTCYAQCgAQGqAQdnd3Mtd2l6wAEB&sclient=psy-ab)

Title: Re: Les Holman Oil breather separator
Post by: Bob Wood on August 03, 2020, 01:24:28 PM

Just an update on my Red Bull oil separator,  see see my 2017 post below. I finally took it off to clean it and check for oil. So in 3 years I flew 140 hours with the gizmo on and found about 1/4 teaspoon of oil in the bottom of the can.  I have no oil anyplace on the plane except the occasional drop or 2 after replacing rocker covers.  Works very well.

Bob Wood

Title: Re: Les Holman Oil breather separator
Post by: Mark Kramer on August 04, 2020, 04:50:20 PM

Dan, I think the reed valve set up is probably the way to go. Will probably have to mount remotely, as the flat spot on top of the engine is I think not large enough. Bob, what is on the top of your engine that the hose to your Red Bull can originates from? I would like to have a reed valve small enough to fit the top of my Mosler case. I’ve seen a picture of one in the Mosler manual, but not able to find one. The Hummel list shows two, a small one and a large one. Wonder what the small one looks like?

Title: Re: Les Holman Oil breather separator
Post by: Bob Wood on August 05, 2020, 01:32:28 PM

Mark,
All I have on top is the reed valve breather from Scott Casler. Just a clear hose off of that to the can.

Bob

Title: Re: Les Holman Oil breather separator
Post by: Mark Kramer on August 05, 2020, 01:50:48 PM

Bob, I gotta call him and see if I can get a small one. Will have to drill and tap some holes. Right now I have a can with scrubbie stuff in mounted on top of the engine. Will try it in the next few days. Working on installing Belite tc-4 temp gauge right now

Title: Re: Les Holman Oil breather separator
Post by: Bob Wood on August 06, 2020, 07:48:16 AM

Mark,
I am sure he has them. You can see mine in the pic below. Probably swap out your bolt on with this reed and you are set.

I also run belite gauges. The Tach,  VSI, alt, airspeed combo,. inclinometer, and cht/egt combos. They are great.!!

Where are you located? How much do you fly?

Title: Re: Les Holman Oil breather separator
Post by: Mark Kramer on August 06, 2020, 03:40:53 PM

Hi Bob, talked to Scott today, the vw breather is 3 inches square and will not fit on the flat spot on top of the Mosler case. I might try and make an adapter to use one, but would rather try to find one that was originally used on these engines. I would have to though, drill and tap holes, as there are none for bolts. Engine also has no dip stick hole. Weird. Anyway...got my private ticket in early 90s, recent flying was a Rans S4 Coyote taildragger. Flew it for 3 yrs , recently sold it. Anybody out there that might know where to find one of those little 2 bolt reed breathers, please let me know.
Thanks Mark

Title: Re: Les Holman Oil breather separator
Post by: Mark Kramer on August 06, 2020, 03:44:49 PM

Oh yeah, I live in southern Maine. Too cold for winter flying here, for me that is. Nothing but trees underneath you also. A simple power failure could be bad

Title: Re: Les Holman Oil breather separator
Post by: Mark Kramer on August 06, 2020, 04:20:57 PM

Oh hey Bob, or anybody,
A pic of the engine and the little valve from an old Mosler catalog.

Title: Re: Les Holman Oil breather separator
Post by: Bob Wood on August 07, 2020, 06:36:10 AM

ok, too bad the case 1/2 ridge is right there if that area was smooth you could maybe bolt the 3" one from Scott right on...

Title: Re: Les Holman Oil breather separator
Post by: Mark Kramer on August 10, 2020, 04:56:56 PM

Well, ran the engine again today with the latest rendition for crankcase venting and oil separating. Worked great, not a drop of oil came out. I used an Aluminum catch can full of that stainless steel scrubbie stuff, with an automotive Pcv valve at the top with a hose to a clear water bottle so I could monitor it for oil. I do have a plan to lower the catch can, removing some fittings. I think they would break anyway. The engine shakes more than I like, spits fuel out the overflows, and the tiny tach is all over the place. Pretty sure I have the hub balance weight where it belongs, didn’t seem to make much difference from when I ran it last. Advance the throttle and one exhaust gas temp climbs over 1200 quickly. Is it hard to tune when it shakes, or does it shake because it is out of tune? Also not sure if I’m getting a full 28 degree spread out of the Morse Fairbanks magneto. I have it set to fire during hand propping, so I won’t get bit, but not sure if it is advancing to 28 degrees back. My brain hurts.

Title: Re: Les Holman Oil breather separator
Post by: Mark Kramer on August 10, 2020, 05:02:58 PM

Oh, forgot. Here’s a pic or two

Title: Re: Les Holman Oil breather separator
Post by: Mark Kramer on October 03, 2020, 05:33:40 AM

Before I talk about my breather issues, let me catch you up on my carb changes. Took the new VM 26 carbs off and went back to the stock arrangement. Drop down manifold with the single Zenith carburetor. This was not without problems. I had to make a carb heat system. Turned out pretty cool I think. Running the engine, I couldn’t get the plugs to look the same during carb adjustments. Found out the intake manifold flanges were warped causing vacuum leaks. Made them flat and cured that issue. Runs great. This engine is supposedly 40 hp at 3200 rpm. It’s bore and stroke are 94 x78. Compression is 141 and 145. Pulling the prop through slowly you can feel no leak down. I do not feel like it has excessive blow by. Now.... after doing Leonard’s, suggested 4 minute WOT test, I have discovered my oil separator set up is not working the way I had hoped. After two and a half minutes oil spewed out the filter. I am at my wits end over this issue. Somewhere in the manual, Mosler talked about a new oil filler/ breather apparatus, no picture of course. Top of the engine has a 1 inch hole, the 1/4 inch hole I put there. VW engines have a much larger hole. The smaller the hole, the greater the velocity of stuff coming out. Maybe harder to separate oil out? Don’t want to tear down a great running engine at this point, but I’m thinking about making the hole much larger, slowing down the escaping gasses, so some escaping oil can fall back in easier. Don’t know if I’m on the right track here. I feel like a two cylinder engine that is missing the other two pressure balancing cylinders, with a very small crankcase, is going to present certain PCV issues. There’s got to be a way. Some pics of the engine top and my failed separator.

Title: Re: Les Holman Oil breather separator
Post by: Mark Kramer on October 03, 2020, 05:42:38 AM

For some reason, the forum will not let me post photo’s. Says to contact forum administrator. I have no idea how to do that.

Title: Re: Les Holman Oil breather separator
Post by: Kamcoman77 on October 03, 2020, 11:04:29 AM

Mark, perhaps nobody has mentioned this, but there is usually a plate or wire mesh under the Hummel breathers to keep oil from being thrown off the cam gear directly onto the reed assembly. On the VW case a stock baffle plate works, but on the Mosler there is no room for this plate. Like Dan suggested, is there any place on the Mosler case a new hole could be drilled, large enough to put your breather in, that is not in line with the cam gear or crank throws? I'm putting my breather on the side of my VW case and not using the stock location.

Title: Re: Les Holman Oil breather separator
Post by: Dan_ on October 03, 2020, 02:47:56 PM

Quote from: Mark Kramer on October 03, 2020, 05:42:38 AM

For some reason, the forum will not let me post photo’s. Says to contact forum administrator. I have no idea how to do that.

From the main menu...

https://www.eaglersnest.com/forum/index.php?action=contact

Seems like you posted some before... what has changed..?

Title: Re: Les Holman Oil breather separator
Post by: Dan_ on October 03, 2020, 02:57:24 PM

Call Scott Casler and see if you can ship your engine to him.  It will come back ready to fly...

HUMMEL ENGINES

5464 E. STOREY ROAD

COOLIDGE, AZ  85128

(520) 723-5283

OWNER:  SCOTT CASLER

Title: Re: Les Holman Oil breather separator
Post by: Mark Kramer on October 04, 2020, 05:13:37 AM

Yeah I get the deflector plate in the VWs. Wish I could post pics, because you could see at the bottom of my last set up, I had a 1/2 in copper elbow that went inside the engine facing away from the timing gears. I think the gases moved too quickly through that portion into my separator tank to allow some oil to gravity back in. I have read some stuff about German systems where they say you can have a separate drain without a check valve as long as the oil returns below the oil level in the crank case. Just thinking out loud here but, if the pressure has a easy way out the top of the engine, why would it push the oil up to the same height as where the air is escaping? Separating the oil from the air coming out isn’t the difficult part, its getting the oil back in to my 1.25 qt capacity sump. I think a separator tank sitting over a very large hole in the engine top would slow down the pressure movement enough to allow oil to fall back in. The hole under a VW breather is 3 or 4 times the area of mine. Not sure if I’m ready to cut such a large hole yet. There also doesn’t seem to be anywhere else on this Mosler case to make a hole for a breather. My engine runs great, and I can’t really afford sending it to Scott, so hoping to get ideas from folks on the forum.

Title: Re: Les Holman Oil breather separator
Post by: Mark Kramer on October 05, 2020, 04:07:31 PM

Here are a few pics. One shows the small hole in the top of the engine. One shows my separator/catch tank, the other shows my home made exhaust and carb heat box. I think the small hole might be part of my problem.

Title: Re: Les Holman Oil breather separator
Post by: Suomelainen on November 28, 2020, 03:25:38 PM

Looking at this perplexing problem I wondered if the larger hole on the vw case allowed some of the oil to drip back into the case. Few thoughts come to mind one is perhaps putting in a couple of elbows would help reduce the velocity and two perhaps drill an other hole to allow the blown out oil to drip back in. Ultimately a larger hole could help. Also the longer hose on other setups might actually increase the volume enough to help depressurization. A flapper valve near the case could also help as then the volume of blow out would be reduced due to the partial crankcase vacuum.  Sure is a vexing dilemma.If I was having this problem I think I would fabricate a custom flapper plate/valve near the case.

Title: Re: Les Holman Oil breather separator
Post by: Mark Kramer on November 29, 2020, 05:37:15 AM

Solved this problem. Go to main page, recent posts, see Mark Kramer CB40 Mosler engine