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Ian C
31-08-05, 20:19
Name:
Breather Systems

What is it?
Breather systems equalise the crank case pressure created by blow-by, and maintain the crankcase at slightly below atmospheric pressure to ensure that blow-by gases and oil cannot enter the atmosphere.

A mighty fine article on breather systems by our very own Digsy is attached to this post. Jolly good for anyone messing with catch cans or single turbo conversions...

-Ian

null
31-05-08, 22:45
Is it illegal to run a car with an open breather system between MOTs?

Are there any reasons besides oil loss that would discourage the use of an open breather system?

After reading the very well written pdf, I have the impression an oil separator or catch can would be enviromentally friendly, but add weight forward of the CG. Even if it is only a few hundred grams!

Briggsy
03-05-11, 16:09
Is it illegal to run a car with an open breather system between MOTs?

Are there any reasons besides oil loss that would discourage the use of an open breather system?

After reading the very well written pdf, I have the impression an oil separator or catch can would be enviromentally friendly, but add weight forward of the CG. Even if it is only a few hundred grams!Its the loss of oil onto roads that's the prob potential hazard for other drivers

hodge
03-05-11, 16:15
If your engines healthy you shouldn't lose oil.

Scott
03-05-11, 16:16
Holy thread resurrection batman.

Scott
03-05-11, 16:18
If your engines healthy you shouldn't lose oil.

I don't think that's true. Regardless of how healthy an engine is running, if you have a breather system, you will get oil vapour released. It is after all open to either atmosphere or the intake system. The fact that the stock system runs a vaccum will mean that this vapour will be sucked out and into the intake to be burned off etc. With a catch can, you simply have this in the middle to catch the vapour.

Granted, you shouldn't lose quantifiable amounts of oil, but you will certainly lose it over time.

hodge
03-05-11, 16:29
I had a catch tank fitted to my last Supra between a vac reference and the tank only ever had petrol smelling water in it and not to much of it really never had oil.

Scott
03-05-11, 17:55
I had a catch tank fitted to my last Supra between a vac reference and the tank only ever had petrol smelling water in it and not to much of it really never had oil.

Was that on an N/A? Just I'm not sure what you mean by vac reference?

mellonman
17-10-11, 11:42
there are so many differnent ways of doing the breather system, some people leave sock intake side and put a catch tank on exhaust side and back into intake (closed), some just put filters on the breather pipes, some run both breather to catch tank and just vent to air, with all these other ways what is the right way?

Joeatphr
19-10-11, 15:18
If your engines healthy you shouldn't lose oil.

When you run boost or in the Supra's case a lot of boost. Oil is forced out, not by having a weak motor but because thats the nature of forcing 20-40psi of air into the motor. Its simply a catch can to get all the oil and either recirculate it or drain it in a more proper place.

xeqution
24-10-11, 03:44
That was a great PDF! thanks for sharing.