How are you running your Crank CAse Breather

[pcar9119]

I was curious about after you do a Carb conversion, how you run the crank case breather. I have seen the catch can style, looks pretty fancy. Was wondering what other options i have. I want to get her back on the road this weekend. I will just make something work if I have to, but would like advice. Thanks.

[911pcars]

To make it work this weekend, source any convenient plastic container, then route the oil filler breather tube directly into said container. If there's a restrictor in the hose, remove it.

For the long term, there are any number of custom-fabricated setups, but nothing off the shelf. These include custom-made and repurposed tanks of plastic or aluminum; windshield wiper or radiator overflow tanks and dedicated aftermarket breather tanks and catch cans with hose fittings, most of which are too small for the 911 vent system. For atmosphere venting, many use a small breather cap designed for venting V8 engines and mounted on the valve cover.

Go to the archives and perform a search using the terms such as: "crankcase vent", "crankcase ventilation", "crankcase breather", "catch can", "breather tank". Some vent to the intake system (desired) and some vent directly to atmosphere (second choice).

Hope this helps,
Sherwood

[psalt]

A catch can is a racing rule requirement. On a road car, I vent the crankcase to the oil tank, then vent the oil tank with a short piece of hose to an "S" or "Z" bend of pipe to a foam sock filter. The idea is to use large diameter pipe to decrease the velocity of the gas and the bend to separate any oil and let it drain back to the tank. Venting the crankcase blowby to the intake is only desirable from an emission standpoint. On the knock prone 911 engine, getting the hot crankcase fumes and the oil mist out of the intake air is worth several RON of octane requirement.

[sjf911]

This is not a carb'd car but I had similar issues with my turbo conversion and went with a catch can.

[pcar9119]

Thanks, I think I have it figured out to work for now. I think i need to replace the lower valve cover gasket now, and see if the oil leaks will stop. Man I just wanna drive this thing on a nice roas trip. But I hate the fact that it's got that oil leak right over my headers, and it smokes. I will change the valve cover gasket and see what happens...

[Evans, Marv]

I found a Moroso catch tank similar to Steve's on Ebay. Don't remember how much it cost. Worked pretty well. Try searching for some of the headings Sherwood mentioned.