Oil Breather

[AndyDuke]

My Taylorcraft used to have an A65 engine, and was prone to throwing oil through the oil breather. Now that I have upgraded to a C85, I expected that oil consumption would be less but I still find that the engine looses most of its oil through the breather.

I discussed this briefly with Forest and he has advised that this is probably due to the end of the breather tube being in a low pressure area. The effect of this is to suck oil out through the breather.

One suggested cure is to put a 'whistle hole' in the breather tube to relieve the pressure so that less oil is sucked out. The question is where?

The attached photo shows the routing in the oil breather. Any suggestions on location and size of the hole.

[Carl Ellis]

Some of the Cub guys have been installing a longer tube into the crank case. I thought this was a pirate "STC" but I heard mention somewhere that Continental had issued a service bulletin about this and it is an approved "mod". Unfortunately, I can't remember the reference. Does this ring any bells for anyone?

- Carl -

[selje]

I had an Air-Oil Separator (Turbo 20) put on a C90 in an early Super Cub and it was remarkable the absence of oil use and the nearly clean belly. Can recommend it.

[Rich. Anderson]

Vintage Aircraft of EAA came out with a fix a few months back for the oil breather tube to help stop oil being lost through the breather tube. Contact the above for a copy of the fix. It is a continental fix but expensive through Continental but can be done by any A&E easily and cheap.

[CraigH]

Had a 'whistle hole' in my C90 equippec Cessna 140A. It seemed to keep the blown out oil to a minimum. My hole was cut about halfway between your suggested spot and where the vent came out the engine.

[Goneflyin]

The owners club newsletter #124 12/2003 had an article on extending the breather tube fix for the oily belly blues.

Bill

[AndyDuke]

Thanks for the replys out there. I will add a whistle hole this weekend mid way between the oil brether outlet and the arrow on the picture. I should be able to determine fairly quickly if this has had an effect on the oil consumption, especially as I have just done a 25 hr oil change on the engine.

If this doesn't help then I will investigate the Continental mod.

[Acroeric]

I used the Cessna Aerobat breather fitting. It protrudes into the crankcase about 1" more than the stock unit. Like a dummy I bought mine from Cessna for $200 or so. One can be made by brazing or welding a short piece of tubing into the stock fitting. I will see if I can round up a part number for you guys. Even flying aerobatics in the clip wing I never lost much oil through the breather.

[Dick Smith]

Crankcase breather fitting info

Thought someone might be interested in this info.

http://www.mooneymite.com/maintenance/continentalbreatherfix.htm

Dick