update to "its hot out there & under hood"

[james49ply]

I have been concerned with the engine temp rising to 180-185 at 60mph, did some checking and found nothing that was wrong to cause this. Just for the H of it I took the hose from the waterpump to the heater and rerouted it to the outlet on the back of the head, suprize, suprize overheating gone! Now it tops out at an acceptable 170 at 60 mph.

Just thought I would pass one the information.

[pflaming]

It might be cooler in the cab also. I think many, years ago, turned off the water flow to the heater in the summer. My block has a petcock so I could if I wished.

[jd52cranbrook]

Doesn't water circulation also stop if you turn the temp to cold?

[greg g]

It stops only to the point that the valve works. Most heater valves I have ever seen do not shut off completely.

[JIPJOBXX]

I would think that the water heater would be heat sink for the engine and it would run cooler if the heater was on.

[jd52cranbrook]

You are correct, especially in systems without AC. In fact that is a old trick when engines run hot with no where to stop and fix it.

[Niel Hoback]

Gregs right, I had to cut my hose and stick in a 1/2' dowel piece to get the water to stop.

[Tony_Urwin]

Maybe the heater core is plugged up. His engine might benefit from the increased circulation when the heater is bypassed.

[james49ply]

all heater cores have a restrictor in the return side, this holds the heat in the core longer, still part of present day vehicles. bypassing allows the water to run faster from the rear of the engine to keep it cooler. if you want to be cooked in the cabin turn on the blower high speed and will help cool engine too.

[jd52cranbrook]

It stops only to the point that the valve works. Most heater valves I have ever seen do not shut off completely.

I think the reason for that, in these Flatheads at least is to help cool the rear of the engine. I read somewhere on here now that I remember. A difference of 5-15 degrees increase in heat in the rear two cylinders can be caused by blocking the heater hose off. So instead of blocking it off, it is best run a loop between input and output?

I am running Vintage Air, I better check my own water flow.