Matt Liggett wrote:
>
> This regards the 1275 in my '70 Midget. I'm concerned about the big
> "breather" on the front of the timing cover. If I understand
> correctly, this should be a PCV valve, correct? That means a one-way
> valve that flows only from the crankcase OUT. I thought mine might be
> broken, so I pulled the line off that goes to the carbs and sucked on
> it and blew through it. It was clear both ways. Does this mean my
> crankcase might be sucking in fuel-air mixture through this valve?
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No what that is? The emoticon for ass-backwards.
Crankcases don't suck. They blow. Ever heard of blow-by? The crankcase
is where it goes as it blows-by the rings. Anything that gets passed the
rings builds in the crankcase and has to go somewhere.
And that crankcase breather off the timing cover is the normal 'vent'
for an 'A' series engine. In the emission era I think it went to the
'gulp valve' which was a funny looking, pancake-topped thingy that
screws into the middle of the log manifold (British PCV valve). At least
I would assume it does. On my midgets it was long gone. The crankcase
breather on my last midget has a 'Y' connection where little pipes fed
it in just past the dampner pistons on the SUs. It doesn't hurt anything
there.
> How do I replace it, and should there be some kind of foam "breather
> filter" element as in modern cars? I considered just buying a generic
> import PCV valve and putting it inline in the hose that runs from the
> timing cover to the carbs. Would this work?
The PCV valve needs manifold pressure on one side of it. So you would
have to plumb the other side back into the log manifold.
Bob Allen, Kansas City, '69CGT, '75TR6
PS: Some of the technical wizards will respond that if you had the
super-deluxe, fancy-smanshy, gee-golly piston rings, then you could, in
fact, see vacuum in the crancase when decelerating. To them I can only
respond with ;~P*****************
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