Breather Modification

[astjp2]

I must be bored, here is something that I found on the breathers....Tim

[Hank Jarrett]

Re: Breather Modification

I did this to mine and my oil consumption dropped through the floor with NO mess on the belly! Several others have since done it with the same results. EASY and it WORKS!

Hank

[Ragwing nut]

Re: Breather Modification

Ercoupes had these too. not every engine needs one, but if you got one that likes to push oil, its a good fix for it.

[TimHicks]

Re: Breather Modification

I made one of these and installed it on my new C85. But before I ran the engine, I got cold feet and ended up buying one for more than $200.
I still get a few drips of oil on the hangar floor from the breather tube after every flight. And oil on the belly.
But I'm not complaining.

[PA1195]

Re: Breather Modification

Can't fix blow-by past the piston rings or valves (via exhaust valve through the cover area) with a mod. They were designed for aerobatics (C-150 Aerobat) and can apparently reduce direct oil pickup in those situations. But if the crankcase if being pressurized via blow-by then address that. I did it to my PA-11 and it changed little on a tight engine. I did not have it done to my current ride as I wanted to know if and when oil blow-by increased so I could deal with the cause. A few drops of oil are expected on a non-oil fume recirc engine.

Gary

[Hank Jarrett]

Re: Breather Modification

The key to the reorientation of the elbow is that the oil vapors condense on the inside of the tube and since it is tilted up the drops of oil run back into the engine. If the tube is turned down the drops drip out the end.
A lot of blow by will still cause some oil on the belly either way because you can't condense it all out. At least this method cleans up normal oil loss. If you still see oil on the belly it is time to look deeper.

Hank

[PA1195]

Re: Breather Modification

Yes Hank that seems to be the case...upturned elbow helps. I started out on a fresh C-90 overhaul (last plane) with a normal installation. I was getting some minor dripping (maybe rings not fully seated or too much oil) so had the tech add the internal extension. Same bypass flow. He then turned the elbow up and it quit most of the outflow. But, in cold weather the exposed run of hose over the top of the front cylinder became a concern for moisture condensation so we lagged the fitting and hose with insulation and left the project for another.

I've installed catch cans at the outlet of the breather hose. Ran them into the side of a small firewall mounted (hose clamped) soup can that could be emptied. Also always add a pressure relief hole upstream in the hose or tubing in case the very end freezes. I prefer hose to metal as it seems less prone to freezing the contents. On one winter installation I used clear flexible tubing so I could see any internal blockage.

Gary

[Guest]

Re: Breather Modification

Can't fix blow-by past the piston rings or valves (via exhaust valve through the cover area) with a mod. They were designed for aerobatics (C-150 Aerobat) and can apparently reduce direct oil pickup in those situations. But if the crankcase if being pressurized via blow-by then address that. I did it to my PA-11 and it changed little on a tight engine. I did not have it done to my current ride as I wanted to know if and when oil blow-by increased so I could deal with the cause. A few drops of oil are expected on a non-oil fume recirc engine.

Gary

Made juckle Gary, not at you.

Vents won't stop blowby, amen.

But I guess a clever fellow with some tubes and check valves could connect between valve cover in just the right sequence so the gas from leaky exhaust stem from cylinder N in the firing order squirts over to the leaky intake stem of cylinder N+1.

LOL

What a sight that would be!

Dave

[PA1195]

Re: Breather Modification

One of my thoughts in a row was to feed the blow-by through an orifice (1/8" primer fitting or whatever that's small) into one of the primer holes in the induction spider. That's until an experienced mechanic suggested it might lean out the fuel mixture and so on. I didn't follow through without his consent. Next was to feed it into the top of the airbox on the cold side through a bulkhead fitting. Didn't happen either but might some day when the EPA decides I'm a hazard to the environment.

These are all thoughts from a too long Alaska winter's mind. Happy Memorial Day all...time to create a little air pollution and burn a chicken on the grill.

Gary

[astjp2]

Re: Breather Modification

Probably not, not enough flow to really change much. Primer fitting does not flow oil too well either. Your carb is probably pretty rich anyways...Tim

One of my thoughts in a row was to feed the blow-by through an orifice (1/8" primer fitting or whatever that's small) into one of the primer holes in the induction spider. That's until an experienced mechanic suggested it might lean out the fuel mixture and so on. I didn't follow through without his consent. Next was to feed it into the top of the airbox on the cold side through a bulkhead fitting. Didn't happen either but might some day when the EPA decides I'm a hazard to the environment.

These are all thoughts from a too long Alaska winter's mind. Happy Memorial Day all...time to create a little air pollution and burn a chicken on the grill.

Gary