Heater matrix Plumbing

[Andy Green]

Hi all,
<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com<img src=" /><o></o>
Somebody kindly posted the following coolant circuit diagram which I’ve been studying for my installation; however it has raised a question regarding the flow to the heater matrix. <o></o>
<o></o>
I not that familiar with the Ford 302 engine, but my general understanding is that the heater feed is out of the top of the head (before the thermostat) and the return is back to the pump. On the attached diagram, the return is on the feed to the radiator, which will result in no flow through the heater matrix. Have I missed something or should the heater return be into the other pipe to the radiator?<o></o>
<o></o>
Regards<o></o>
Andy<o></o>

 

[Chuck]

It would appear that the drawing is correct.

The hot coolant is under pressure so it will flow through the heater regardless of whether the return is on the hot side or the cold side of the radiator.

The easier way is to just connect it across the input and output at the radiator, but that is not as effective and would provide little heat when the thermostat is closed, but it avoids that long extra pipe through the tunnel (and who will be driving their GT when it is REALLY cold out anyway?)

 

[Keith]

Andy,
That was my assessment too. By hooking up the heater to the radiator tubes the only time that there would be hot coolant availlable to the heater is when the thermostat was open, and the only time that there would be flow thru the heater core would be when or if the pressure drop across he radiator was greater than the pressure drop across the heater core. My guess is that it probably does not work well, however I do not have mine hooked up that way so I don't know for sure.
I ran seperate 1/2 inch copper tubes down each side of the main coolant tubes and machined hose fittings (I took 1/2 copper to 3/4 NPT adapters and machined the 3/4 NPT to a barb fitting) to adapt to the 5/8 heater hose. I ran one to a heater hose fitting at the top of the intake manifold and the other to the heater fitting on the water pump just like in a "normal" application. I have not had the car on the road yet but running it in the shop I get air out of the heater so hot you can't hold your hand in front of it.
Yes, it is extra work but the heater does actually work..............
I believe there is a photo of the tube set on my build log.
All this said I would probably have to agree with Chuck, I really don't think I will be driving the car in the kind of weather where I would need it anyway. But if I do I will have heat.
Keith

 

[Simon]

Drove mine in freezing fog. boy was I glad of that heater!