An inquiry from a fellow roadster owner concerning the position of the Cock handle
led to a review of the part and its function.
The Cock-three way is the correct Nissan parts catalog description for the valve at the back of
of 1600 intake manifold that controls water flow to the heater.
Looks to be a proper quaint old British part.
2 variations. Early style Part # 14050-12900 (1500?) with the short copper outlet pipe to the heater hose and
later style part # 14050-14600 (1600 ?) with the longer copper outlet pipe to the heater hose.
Positioning the handle at 12 sends water to the heater.
The clever Japanese even stamped an "H" on the body but do you point the small end of the handle at the "H"?
NO. The broad flat part of the handle points at the "H" to open the valve.
Positioning the handle at 9 stops water flow to the heater and
returns water to the cooling system via the water tube under the carbs.
The back of the valve shows that it was designed to move only 90 degrees between 9 and 12.
There is a cut out washer that engages a post on the valve body.
In practice this washer is not tight enough and allows the
handle to turn 360 degrees. With the handle at 3 and 6 there is no flow to the heater or return to the system.
With the handle at 9 or 12 water is continually flowing.
Does this provide nominally better performance from heating the
intake manifold and slightly better radiator cooling?
If you have not worked with this valve I guarantee it will be frozen and the handle will not move.
Do NOT force the handle with pliers etc. Again it is guaranteed to break. The valve is brass on brass. no seals etc.
Spray lots of solvent on the handle/body junction. Pry the spring on the back slightly inwards to release tension and
break the handle lose while gently turning the handle. Usually this can be done with the cock in place.
This is what happens when we have too much covid-19 isolation time.
Ted
