I have a 4cyl Ford Dorset engine and I want to connect it to the heating
coil in calorifier. I assume the aim is to have the engine cooling water
flowing through the calorifier before it reaches the bowman heat exchanger.

There is, what looks like, a 3/8" bsp plug next to the thermostat housing,
but if I take a feed from here I will effectively bypass the thermostat and
the engine would take ages, to reach it's working temperature, if at all.

If I put 2 tee pieces between the engine and the heat exchanger will the
water actually flow round that loop, the flow and return would be very close
together.

If I put a tee in the flow before the heat exchanger and the return after
it, would I risk significantly bypassing the heat exchanger.

Any ideas, suggestions? I guess the set up is fundamentally the same on any
engine.