SonexBuilders.net

Found this for a home-made air/oil separator. I think I'm going to make something like this.

http://www.y8s.com/celica_gone/air-oil/

Mike Smith
Sonex #439

Great tip Mike. I want an oil separator but I can't justify the $120 that Sonex wants. I know others are making them out of simple cans and water bottles...this may be a good middle ground.

Mike,
Thanks for the idea. Two thoughts:
1) I wonder why the construction specifies the use of epoxy to hold the PVC parts together? Usually "gluing" of PVC is done with PVC "cement", which is actually a solvent that welds the PVC parts to each other. I'd trust it a bit more than epoxy.
2) Temperature:
Per the info at this site (http://www.harvel.com/piping-systems/gf ... e-derating ), the maximum service temperature for Schedule 40 PVC is 140 deg F (and solvent connections are preferred at these higher temps--see above). At 140 deg, the pipe can take pressures only 22% of what it can withstand at 73 deg F. Now, in an air/oil separator the container won't see any real internal pressure, but I would be concerned about the strength of the threaded connections, etc.

CPVC pipe is typically used for higher temp applications. Most hardware stores have a smaller selection of CPVC pipes and fittings compared to PVC, so it might be more challenging to find the needed parts.

Anyway, maybe the PVC idea will work just fine, the preceding is offered for consideration.

Here is a decent air/oil separator that is reasonably priced:

http://www.aircraftspruce.com/catalog/e ... eather.php

At present I do not use an air oil separator as Myunn isn't putting much oil out the breather yet. When I do need one I suppose this is the one I will use.

FWIW,

Dale
N319WF

daleandee wrote:Here is a decent air/oil separator that is reasonably priced:

http://www.aircraftspruce.com/catalog/e ... eather.php

At present I do not use an air oil separator as Myunn isn't putting much oil out the breather yet. When I do need one I suppose this is the one I will use.

FWIW,

Dale
N319WF

I like that design. You could either route the overflow to a catch bottle or back to the crankcase. Simpler and smaller that the Sonex one. I think the sonex one weighs a couple pounds too.

mike.smith wrote:Found this for a home-made air/oil separator. I think I'm going to make something like this.

http://www.y8s.com/celica_gone/air-oil/

Mike Smith
Sonex #439

I sort of wonder how the plastic will hold up with hot oil and other chemicals blown thru it. Might it melt? Might it disolve? Some preinstallation experimentation may be wise. Otherwise, appears to be a good idea , and a whole lot cheaper! :)

I am suspicious of using PVC. I made my air/oil separator from a quart paint thinner can. I soldered copper tubes into the top and bottom and filled the can with copper "Chore Boy" pot scrubbers. I also added a return tube from the bottom of the can to the valve cover.

With the PVC idea and the one above using the paint thinner can, what did you do to keep the chore boy pieces from draining back into the valve cover? Do you have some sort of screen or way to keep the pieces that will eventually fall off from flowing back with the rest of the oil? I seem to remember a few years back where a few people were putting the chore boy scrubbies in the hole just under the plate for the breather hose eliminating the need for an air/oil seperator. Sonex strongly recomended against it since small pieces of the chore boy could fall back into the engine .

Keith

kmacht wrote:With the PVC idea and the one above using the paint thinner can, what did you do to keep the chore boy pieces from draining back into the valve cover? Do you have some sort of screen or way to keep the pieces that will eventually fall off from flowing back with the rest of the oil? I seem to remember a few years back where a few people were putting the chore boy scrubbies in the hole just under the plate for the breather hose eliminating the need for an air/oil seperator. Sonex strongly recomended against it since small pieces of the chore boy could fall back into the engine .

Keith

I haven't done anything. I think there is a difference between the copper scrubbers and the stainless steel ones. I have never seen any sign of metal in the screen during oil changes. I imagine the nylon scrubbers will work too.

If you were concerned you could put a filter in the oil return line going back to the engine.

Charlie