17 replies to this topic

[T.Harper]

Inspected the assembly and oil vapor is getting into the inlet manifold. The diaphragm is really a gasket and I can't understand how this arrangement works unless something is missing  

That diaphragm is toast!  One for the hall of fame. 

 

I was always a bit suspect of the PCV valve but tested mine on a vacuum cleaner over the summer and it does indeed work (i.e. blocks off high vacuum; opens up during partial/low vacuum) - so it's worth a spin.  If you don't get on with it then sell it on ebay as they go for £20-30.

[Edington]

I'm still puzzled why it shouldn't let oil vapor into the inlet manifold even at low vacuum. Anyway I took it off, plugged the hole and vented the breather to atmosphere under the car. Still smokes so I assume there is oil residue inside the inlet manifold. So I'm going to remove the carbs again and fit a clean inlet manifold without the PCV connection and see what happens. I am waiting delivery of a new spring and diaphragm from Somerford Minis if I decide to refit the PCV at some point.  

[sonscar]

The filling in the breather can should help condense most of the oil out and back into the sump.I have one of these valves on my MGB and it works well.Steve..