Breather tube

[TimHicks]

My aircraft has always had a flexible plastic tube for a crankcase breather.
So I bought a new one for the new C85. But someone told me that correct is an aluminum tube.
Anyone have any pictures of what the breather is supposed to look like?
What diameter aluminum tube?
How is it routed?
How is it connected to the engine?

[cvavon]

Re: Breather tube

Tim the new baffels had a hole that lined up with the elbow and sent the tube down under the engine. On the 65 it went over the top at a up angle and it did not drip oil at all the one on the 85 drips when it is shut off after a flight

[TimHicks]

Re: Breather tube

OK, Chuck,
Thanks.
It looks like I need to get some 5/8" OD aluminum tube.
Connect it to the engine outlet elbow with a short rubber tube and hose clamps.
Send it down through the existing hole in the new baffles.
Then bend it to get it back to the firewall where it exits. Secure with a couple of Adel Clamps where needed.
Does that sound right?
Tim

[Hank Jarrett]

Re: Breather tube

That is the old way. There is a mod that has been recommended by Harry Fenton and the Cub guys to modify the elbow by brazing in a lip for oil control and route the tube OVER the RH Cylinders, through the rear baffle, down the firewall and out.
The change seems to significantly reduce the oil on the belly and oil consumption since pulsing of the breather gets oil into the tube, but with it going OVER the cylinders it drains back into the cam area instead of down to the ground.
I will try to remember to take the camera out and get a photo next time out. If someone else doesn't post the drawing for the elbow mod I will try and find it and scan it.

Hank

[Guest]

Re: Breather tube

Here are pictures of mine.

[LostnSpace]

Re: Breather tube

Mine is just like Drude's, the ones that run over the top of the engine don't drip on the floor because it all runs back in the engine, including the water, gary

[Guest]

Re: Breather tube

Mine should be aluminum.

I had to substitute copper in 1987 and for 27 years now I have been meaning to replace it with aluminum.

That just doesn't seem to be working out!

Dave

[astjp2]

Re: Breather tube

I have the parker beading tool to put the bulb in the tube, you also want a small hole poked in the tube about 6" up from the bottom so if it ices over you wont over pressurize the case. Tim

[KewFlyer]

Re: Breather tube

Chuck/all:

Chuck: did you route the oil breather tube/hose on the top of the engine [C-85] and down on the back side of the engine?. I'm dealing with this issue right now, since I dont have space to come down on the front of the engine, as in the A-65, and then on a 45 degree + - to the bottom of the firewall.

If I route the breather hose on the top of the engine and then down, I'm concerned with the oil actually not having enough angle/slope to flow down/for gravity to pull the oil down the tube and/or the oil staying in the tube and cloging the tube and possibly the breather and decieving the whole purpuse of having a breather tube.

We did the bulb in the aluminum tube to connect directly into the breather, avoiding the hose connection.

Thanks

Ralph

Tim the new baffels had a hole that lined up with the elbow and sent the tube down under the engine. On the 65 it went over the top at a up angle and it did not drip oil at all the one on the 85 drips when it is shut off after a flight

[KewFlyer]

Re: Breather tube

Hank:

thats exactly what the IA recomended for the C-85 set up, but, I'm just concerned about the set-up over the engine.

I will post pictures of the sut up next week end.

ralph

That is the old way. There is a mod that has been recommended by Harry Fenton and the Cub guys to modify the elbow by brazing in a lip for oil control and route the tube OVER the RH Cylinders, through the rear baffle, down the firewall and out.
The change seems to significantly reduce the oil on the belly and oil consumption since pulsing of the breather gets oil into the tube, but with it going OVER the cylinders it drains back into the cam area instead of down to the ground.
I will try to remember to take the camera out and get a photo next time out. If someone else doesn't post the drawing for the elbow mod I will try and find it and scan it.

Hank

[KewFlyer]

Re: Breather tube

Hank:

thats exactly what the IA recomended for the C-85 set up, but, I'm just concerned about the set-up over the engine.

I will post pictures of the sut up next week end.

ralph

That is the old way. There is a mod that has been recommended by Harry Fenton and the Cub guys to modify the elbow by brazing in a lip for oil control and route the tube OVER the RH Cylinders, through the rear baffle, down the firewall and out.
The change seems to significantly reduce the oil on the belly and oil consumption since pulsing of the breather gets oil into the tube, but with it going OVER the cylinders it drains back into the cam area instead of down to the ground.
I will try to remember to take the camera out and get a photo next time out. If someone else doesn't post the drawing for the elbow mod I will try and find it and scan it.

Hank

[cvavon]

Re: Breather tube

Here are three more photos of the breather on 26658

[Hank Jarrett]

Re: Breather tube

Chuck and I were talking about this and if your engine gets warm enough to get the moisture out of the oil it won't come back down the tube if the tube goes over the engine. There is enough flow through the tube from even small blow by to push it all out and it is warm enough over the engine to keep it dry. Any air coming back up the vertical part after shut down will condense in the cooler vertical part and drain out the bottom. Water shouldn't be a problem and will be less than with the vent going down than up and aft.

Hank

Mine is just like Drude's, the ones that run over the top of the engine don't drip on the floor because it all runs back in the engine, including the water, gary

[Hank Jarrett]

Re: Breather tube

Got back down to the hangar and got some shots of the aluminum tube case vent. Runs UP and over the cylinders with a break at the baffle and then don the firewall and out of the cowl. MUCH cleaner. I used thin wall tube and it IS hard to bend and not kink. Be careful!

Hank

[skip]

Re: Breather tube

I finally got out to get a picture of my '46 BC12D with C-85.

I added the Wolfe air-oil seperator a few years after I got the plane because some drops would get down the tube and drip onto the ramp. The seperator fixes that. I get nothing on the belly from the vent tube.
Note in the second picture in three-point attitude on the ground level with the horizon, the first part of the tube does run up-hill away from the engine. But it seems that there was enough oil remaining in the tube after shutdown to give some drips on the pavement.
The tube seems to be 5/8 aluminum. Without the seperator, the tube just ran down to the bottom of the firewall.