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Breather

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J

JIM NEWMAN

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On top of the valve cover is a T shaped breather pipe. One branch of the T is connected to an air cleaner, the other to the crankcase. What are the consequences of blocking one or the other T branches? What if both were to be blocked? Is this "breather" really necessary to the functioning of the engine?
Thanks for the insights.......
jim
 
If you plug either or both sides of the T, then you won't have a crankcase breather anymore, your crankcase will pressurize, and you may find oil leaks where you never dreamed they could be.
Jeff
 
Jeff is right, additionally if the "T" is screwed down to far in the valve cover it can act as a siphon and load the air cleaner with oil.-FWIW---Keoke
 
Ah, ha! So the fix (or at least a fix) for an air cleaner loaded with oil is to reduce the depth of the mounting of the T. I always wondered why some Healeys' air cleaners loaded up with oil while others' did not.
 
Hi Reid, yes it can occur and depends on the condition of the engine,some do and some don't-Regards---Keoke
 
I would imagine that it also depends upon the condition of the rocker assembly. An old worn shaft will squirt much more.
 
I read an article by Norman Nock of British Car Specialists (Stockton, CA)about a one way valve that goes in line between the "T" and the carb filter. I decided against it because it seemed to me that it would clog with oil if the oil was coming form a rocker arm problem. Has anyhone tried o;ne of these. It sounds like something that came on my "70 MGB they called a check valve.
 
T.H./ Jeff,The valve in question is a PCV Unit. Norman evidently got one to work but I nearly went broke trying different ones and simply could not make them work at speed. In theory the valve inverts crank case pressure reducing the tendency for the engine seals to leak.-FWIW---Keoke /ubbthreads/images/graemlins/driving.gif
 
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