Max,
As it sits now, it does have all the stuff of a '65-'67 PCV
system--vented oil filler cap, vapor seperator with "up pipe" side
plate, and PCV valve.
The car really was built in 1964, and probably left the factory
looking like the first smog diagram on page 14 of the Moss catalog.
If it was first registered in 1966, it may have had to be brought up
to 1965-67 spec. The motor in question is a plain "G", in the 30000
range. The PCV was done in the style of the Smiths fed. mandated
ones, but obviously was done by a dealer or garage. The pipe out of
the manifold was crudely drilled and tapped for a piece of galvinized
plumbing pipe, American thread. My other reason for believing that
it didn't originally have a PCV is that the upper engine parts
(aircleaner and valve cover) are right per that illustration.
It is my understanding that manufactuerers did away with road draft
venting by CA state or federal mandate in order to reduce pollution
by recycling unburned combustion gasses and other vapors back through
the intake, rather than release them straight to the atmosphere. The
valve is there to meter the flow at various manifold pressures, so as
not to foul up the combustion mixture. This was the first step,
prior to post-1968 exhaust air injection, retarded timing, NOX
devices, fuel vapor recovery, etc.
I'm not certain about this, but I remember, as a Southern California
born nipper in the mid-Sixties, that PCV valves were required in the
1965-66 era. Later on, some cars were required to retrofit NOX
devices, though I believe dual SU-equipped cars were exempt, and got
little decals to paste on the window to let the CHP folks at the smog
check roadblocks know that they weren't gonna find that stuff under
your hood.
Max wrote:
>Actually, what you are describing sounds exactly like the factory PCV
>setup on a 66. From what I can tell in Clausager, it is also correct for
>1964 GA series motors (G series motors vented the front side cover to
>atmosphere and had a pipe from the rocker cover to the front air filter).
>This should have a hose from the front side cover connecting to the flat
>Smiths PCV, which is attached to a plumbing fitting in the manifold by a
>very short hose, and supported by a funky angle bracket. See Clausager
>page 61. There are no additional fittings on the valve cover; only the
>oil filler cap.
>
>BTW the positive crackcase ventilation system is not primarily there for
>the environmental benefit. It is there to vent excess crankcase pressure
>to avoid oil blowby into the cylinders. That is why it exists in early
>cars, long before any pollution control regulations were legislated,
>starting in 1967.
>
>It sounds like you have no crankcase ventilation at all at present, since
>you don't have a vent either in the rocker arm cover or the front side
>plate. This is probably a bad idea. I would recommend implementing the
>18GA setup, since you could still use your alloy valve cover. All you
>need to locate is the proper front tappet cover (side plate), since you
>have the right PCV and manifold. A bit of rubber hose and you're all set!
>
>Max
Chris Attias
'64 MGB
'84 Alfa Romeo GTV-6
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