At 03:39 PM 10/22/97 EST, you wrote:
>
>> Questions:
>>
>> 1. What is the function of the spring, disk and post?
>
>... as I understand it -- the "Smith's Anti Pollution Valve" is a
>vacuum regulator, not just a check valve. The idea is to keep a slight
>vacuum in the crank case at all times. This helps keep oil on the
>inside of the engine. This is a good thing. The gases in the
>crankcase are mostly blow-by fuel/air from the rings. Burning this is
>a good thing.
>
>> 2. What is the effect of the spring being missing? Dangerous to the
engine?
>
>I guess it means that the regulator is stuck in the "closed" position
>-- I don't think it would hurt anything --- except it might not be
>scavenging the crankcase effectively at speed.
It may allow blow-by to build up pressure inside the crankcase, which
usually forces oil out, notably from the rear main seal and around
the base of the dipstick.
>> 3. If it were, could I just disconnect the PCV valve from the system and
>> plug the hole in the intake manifold for the time being?
>
>--NO! Unless you want oil on the OUTSIDE of the engine where it does
>precious little good.... Even just venting it doesn't work as well....
>the engine blocks are different -- the earlier blocks are
>vented down near the sump!
I agree - the early TR4 engines simply vented through a pipe, and
spread oil far and wide if rings had any blowby at all.
>> 4. It seems like at tune up time, one is always trying to eliminate leaks
>> in the intake manifold. Doesn't the PCV valve act like a leak in the intake
>> manifold, with similar bad consequences?
>
>No -- it's referred to as a "closed system" and, it still should
>be, unless something is wrong....take the oil cap off while its
>idling -- it will (should) stumble if not stall....
Mine increases idle - I think what is happening is that the vacuum
from the manifold pulls the valve into the closed position when
the crankcase pressure is reduced. This doesn't really introduce
extra air, so idle speed doesn't change.
If the valve is stuck open, or the hoses are leaking, then you
have a vacuum leak. Moss' catalog has a note on the valve
that says you need to make sure the little vent hole on the
oil filler cap is clear. The hole is on one side of the brass
washer-thing under the top of the cap. It allows some air to
enter the valve cover underneath the oil cap.
>>
>> The missing spring not available from any of the usual suppliers. I may
>> have located a source for a suitable replacement. If so, it would be good
>> if the suppliers picked up on it. Anyone have experience working with the
>> suppliers to develop replacement parts sources?
>
>Please let me know about your source. I'd just get a used one if I
>couldn't find new....
The spring (admittedly old) on my car measures 7/8" by 7/8"
uncompressed; it compresses to 9/16" with 8 oz weight
applied. I can't measure more precisely with a ruler and
stick of margarine :-)
Cliff Hansen
1966 TR-4A CTC 64615L
Red, rough, running
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