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Pcv valve

Posted: Fri May 19, 2023 9:54 am
by Classiccars
Is there any reason why a pcv valve cannot be screwed to the rocker cover as opposed to the manifold to save any oil rather than just burning it off.

Re: Pcv valve

Posted: Fri May 19, 2023 10:05 am
by Monty-4
Do you mean so the venting goes the other way through the engine? "Sucking" from the tappet chest breathers or timing cover and out the rocker cover to the PCV valve?

I don't see any problem with it... but also no benefit. Mine has an oil catch can between the tappet chest breather and the PCV valve and it doesn't appear to get too oily in there.

Re: Pcv valve

Posted: Fri May 19, 2023 10:14 am
by svenedin
In your other thread it was explained where to put the PCV valve on the inlet manifold. viewtopic.php?p=689272#p689272

The PCV valve only works in one direction. It has a spring/diaphragm valve inside that operates under engine vacuum from the inlet manifold. This page explains how this rather cleverly designed valve works: https://mgaguru.com/mgtech/engine/cv103.htm

If somehow you did manage to mount it to the rocker cover and connect it to engine vacuum what will you do with your tappet chest breather pipe?

I would suggest you install it as it was intended to be used.

Re: Pcv valve

Posted: Fri May 19, 2023 11:47 am
by Classiccars
Interesting.As the oil is coming through the wire filled cylinder at the front of the engine and out of the breather I thought the pcv would send it back into the engine.I will have to first change the wire in the cylinder and go from there thank you.

Re: Pcv valve

Posted: Fri May 19, 2023 5:56 pm
by philthehill
The PCV valve will send the fumes back into the engine for consumption in the engine cylinder via the inlet manifold.

Re: Pcv valve

Posted: Fri May 19, 2023 6:34 pm
by Classiccars
Thank you as this will burn the oil without returning it for use I may put another breather on the fuel pump area with a catch can.Cant see any other way as the engine has been rebuilt with new piston rings etc.

Re: Pcv valve

Posted: Fri May 19, 2023 6:56 pm
by les
You must be loosing a lot of oil, if you’re concerned about it not being returned for use ? You’ve lost me re the fuel pump area, is that another issue ?

Re: Pcv valve

Posted: Fri May 19, 2023 9:13 pm
by philthehill
The engine may have been re-built but there is re-built and re-built.
If the engine is pushing oil out of the breather in any quantity then there must be problems with the rings and bores.
A re-built 'A' Series engine should not be breathing oil in sufficient quantities to raise concerns.
Les
As regards the fuel pump area I think the OP means using the fuel pump aperture to mount a breather oil separator canister to obtain better crankcase breathing similar to that in the photo below:-
Breather 1.JPG
Breather 1.JPG (1.09 MiB) Viewed 606 times

Re: Pcv valve

Posted: Fri May 19, 2023 9:36 pm
by les
Ahh, I now recall seeing that or similar picture in possibly one of your past posts. I’ve a feeling the mechanical pump aperture is a feature of the Austin variants. I’m sure my van casting is solid. Interesting point re engine building. I would be disappointed. On a brighter note, hopefully the suggestions made will cure things and dismiss any deeper concerns.