I am thinking of making an oil catch can. I'm not sure if I should just run the size hose off the oil filler or if I should make a bigger one. It was not going to recirculate back into my intake.

I have none of the emmisions equipment, the former owner removed it all. I was thinking of even having a little nipple on there for the vent lines from the gas tank. You think those lines might spit out some fuel every now and then?

 

-10 min . On are racecar we put a -10 on the front cover and on the oil fill neck. The one on the front cover is a vent and a drain. Works great!

 

After posting this I realized I really need to be schooled on rotary crankcase vent. WTF is the crankcase on a rotary, just the oil moving in the pan? Only thing I can think of is the oil pressure feeding the internal engine and the return. Sadly to say, and i'm sure many others have not really thought of it either

 

it is pressure leftover from leakage past the rotors from combustion, higher boost results in more pressure and vapor in the crankcase. excessive pressure causes oil to push past internal seals and into the engine or past the turbo.

the engine has 2 vents, 1 up on the oil filler and one on the center iron. on stock engines 1 port is sufficient, on moderately built engines both are tied into a single larger -10 hose. on high horsepower applications the oil filler cap is replaced by a ported cap to increase flow even further.

 

Would the sub zero start tank last as a catch can?

 

probably but it's ugly and would require modification. most often on stockish cars that remove emissions i use the charcoal canister.

 

I like. Thanks for the idea.

 

Thanks for the breakdown! It's raining over here, I want to check that other port you were talking about in the middle iron

 

I currently have a -10AN line coming off my oil fill neck and the regular 5/16"? coming off my center iron both going into a big vented catch can. The catch can has two 3/8" NPT ports on it so I just got adapters for both types of hoses.

Works pretty well so far.

 

Hmm, I looked at my center iron and could not find the other cent line you guys are talking about. I have a s4 13bt. I only see the line off the oil filler

 

it's at the base of the oil filler tube, pointing towards the firewall. it doesn't actually vent the filler neck even though it looks like it does.

the filler neck nipple is near the top of the filler

 

I don't have one. The only one I have is the one at the oil filler neck.

 

look at the black hose.