Heater hoses

[Dogsdad]

Which way do the water hoses connect to the heater on a 1970 1098 engine?
Does the one from the tap at the back of the block go to the top or bottom of the heater matrix?
I have seen both connections on cars and in photos.
Does it make any difference?
R.M.

[simmitc]

I've commented on this before - roughly half the councours "as they were when they left the factory" cars seem to have the hoses one way and half the other; and they can't both be correct. My argument is for the hose from the heater tap to go through the top hole and then to the top pipe on the heater. Warm water from the engine then enters the top of the heater and as it gives up its heat then it cools and sinks to the bottom or return hose. If you connect it the other way around then you will be trying to pump against a natural thermosyphon action.

[Dogsdad]

Thanks simmitc, sounds right to me. “O” level physics must still work.
( showing my age there I think.)
R.M.

[kevin s]

There is anothet logic which i know applies to my tr7v8 if is plumbed with the the exit at the top, any air in the heater gets purged out with the flow if you plumb it the other way the heater is hopeless.