[Drumer919]

We are having a discussion on another form and I wanted to get your opinion since there is so many more people here. Is it okay to plum hot water to the heater core by getting it at the water port on the head? The hose can be secured and/or shielded from the headers to prevent melting it but some people seem to think that its not a good idea.

 

[JWagner]

The hottest water would be at the front of the heads where it dumps into the intake manifold. If you have a place to take water from the head, it would still work, but it would not be quite as hot.

 

[1966_L78]

The hottest water would be at the front of the heads where it dumps into the intake manifold. If you have a place to take water from the head, it would still work, but it would not be quite as hot.

But how much of a temp difference are we talking about, and would it be noticable when running the heater?

No expert here, but you might still need to hook one hose to the water pump, or else you might not get much/any flow through the heater...

 

[Drumer919]

But how much of a temp difference are we talking about, and would it be noticable when running the heater?

No expert here, but you might still need to hook one hose to the water pump, or else you might not get much/any flow through the heater...

Yeah I'd still have the return in the water pump, I just dont have an extra port on my intake for the heater, I already had to drill and tap one for a sensor and there is no space left for another hole.

 

[vrooom3440]

Considering that the water temp runs 10* or more hotter on the head port than it does up in the thermostat crossover... you would have plenty of heat to make the driver warm. So that really is not a reason not to do this.

I think it depends on what you have for bypass setup. If you have other flow to keep the coolant moving then tapping off the center of the head should not make much difference. But if your heater IS your bypass, and on the OEM design it was at least part of the bypass, then you get uneven coolant flow across the heads. That would not be the best thing, probably not the worst but not the best. It could lead to strange expansion/contraction issues which in worst case might cause head cracking or breaking head gasket seal.

 

[Slick71ss]

Can you do something like this?

This is from an 81 Z28 I put together. Ran a hose from the water pump to the heater, and then the return hose from the heater to a port on the radiator. Worked great.

 

[Slick71ss]

Holy smokes! :clonk:

After posting that up it dawned on me that I probably had that hooked up wrong! I must have been getting a flow through the heater though because it blew hot air.

 

[Drumer919]

Considering that the water temp runs 10* or more hotter on the head port than it does up in the thermostat crossover... you would have plenty of heat to make the driver warm. So that really is not a reason not to do this.

I think it depends on what you have for bypass setup. If you have other flow to keep the coolant moving then tapping off the center of the head should not make much difference. But if your heater IS your bypass, and on the OEM design it was at least part of the bypass, then you get uneven coolant flow across the heads. That would not be the best thing, probably not the worst but not the best. It could lead to strange expansion/contraction issues which in worst case might cause head cracking or breaking head gasket seal.

Sorry to bring this back up but its time for me to do this, its cold out now and I need heat! I have no bypass at all right now and the truck stays at 195-210* under all conditions.

What path does the water take threw the engine?

I have ports between the 6 and 8 exhaust ports on the passenger head and the 1 and 3 exhaust ports on my driver side and could take water from either of those or even from both, then T them together if need be. I guess the third choice would be to use the passenger side ports for the heater supply, still return to H2O pump and tap into that line from the driver head. What would be the best way to do it? Is uneven flow going to be a major thing, or not really.

As discussed, the return will be into the H2O pump. Thanks.

 

[zeke67]

Go out from the cylinder head port and in to the bottom of the water pump port. No need to balance between banks, the head is the inlet to the heater.