Hi from South Afrika

[jondee86]

(07-31-2018 09:40 AM)Witkind Wrote:  Is it possible to completely blank off the water outlet, or do I have to
run a pipe to the thermostat housing?? Will blanking off the outlet lead
to any hot spots around the no 4 cylinder, and how does blanking it off
differ from having it connected to a heater radiator but still having the
selector in the closed position???

I'm inclined to think that having an outlet at the rear of the head has
more to do with packaging than with cooling performance. Having an
outlet at the back of a north-south engine, is convenient for supplying
water to the heater and provides a safe spot for mounting the engine
temperature sensor.

Cooling water distribution from the block to the head is primarily set
by the size and placement of the water holes in the head, block and
gasket. And as you mention, the cooling system must be capable of
doing it's job with the heater tap closed. This leaves only the small
tube connected to the AAV flowing any coolant from the rear of the
head, and that is tiny compared to the flow out of the front outlet.

So while I haven't tried blanking the rear outlet (RWD car), I can't see
that it would be a problem. You only need to find a new location for
the sensor/s. I think USDM versions have the ECU temperature sensor
in the front water neck. And you don't have a heater

NB: Above applicable if you are coverting to a RWD water pipe setup
which has an internal bypsss on the water pump to flow water while
the thermostat is closed.

If you are using the FWD setup, the standard pipework includes a bypass
that sends water to the thermostat housing to make sure the thermostat
will operate. Something like this...



Cheers... jondee86