VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 1 ton truck overheats

I have an overheating problem with my 1928 Chevy, 1 ton truck.
Background:
New radiator core
Correct engine and distributor timing
New spark plugs, wiring, points, condenser, and coil
New fan belt correctly adjusted.

Truck starts up and drives but will overheat.
What is the top speed for a 1-ton truck? I am trying to keep it about 30 mph as the average speed

The idle rod was missing and tried to make one. It works, but I can not drop the engine speed to a good slow speed while at idle. Possible wrong bent rod? Is there an idle rod that I may purchase?

I have been using just water in the radiator.
Should I use straight antifreeze and no water to help keep engine cool?
What is water-wetter as a coolant? Can it be combined with antifreeze?

Any suggestions would be very helpful- thanks

First question is how do you determine that the engine is overheating? Does it boil the water? Can you hear a bumping when the hot engine is shut down? Does it push hot water out the overflow tube? It is showing over 212 deg. F on a thermometer? Have you checked the thermometer in a pot of boiling water? Does it push out water when the engine speed is reduced like at a stop sign or light?

Water is the best coolant as far as heat transfer. It has a few properties that other coolants control. Freezing at 32 deg F and corrosion particularly on steel and cast iron are the prime ones.

100% antifreeze is not a good option as the heat transfer is lacking. Water wetter performance is highly exaggerated and results in much higher internal engine metal temperatures. The temperature of the coolant can in some cases indicate metal temperature but is NOT a good indicator particularly with lower efficient heat transfer agents.

If you might question my advice or knowledge I worked for the second largest coolant supplier in coolant research and development for may years. It may not be rocket science but is not witchcraft either.

You might want to check the torque on the head bolts(55 psi). I had a similar problem years ago. It was the head gasket. How long does it take to overheat.

I would check out the posts in the 1929 - 1932 forums by “ Bearsfan” goes into a good discussion on installing a clear glass filter in the upper radiator hose, a good visual way to check for air bubbles in the cooling system, which indicates air being sucked into the coolant, having air in the coolant is a quick way to create steam, and give the system more pressure than it can take. Check for bearsfan in the member list might also help you find his posts.

Thanks for the help.
Chipper, the truck does push out water once the engine is stopped. I fill the tank up to it is level just below the filler inlet. I do not try to fill the inlet as the water will heat and boil down the overflow tube seeking its correct water level.
Yes, I have had the bumping sound when the engine is shut off.
I let the truck idle after filling the radiator with water to make sure it circulating and to add water to the radiator once it is warmed up. I do not add water and just drive off.
As, for the head gasket, I will check the torque on the bolts. There is not indication of any water seeping around the head gasket or steam coming from the exhaust.
How is air sucked into the coolant? I have not heard of this issue until now!!

The majority of air comes past the packing on the water pump shaft. The pump works by lowering the pressure in the pump cavity that is also how the much lower viscosity air is drawn in.

Only fill to to top of the radiator core. It is a little difficult to see the core as the inlet from the engine head is in the way. The coolant (water in this case) expands on heating pushing coolant out the overflow. Any air mixed in the coolant expands much more than the liquid forcing even more out the overflow. The air bubbles get bigger as the temperature increases and pressure on the coolant decreases. That is often seen nearly immediately when the engine speed decreases or stops.

Well now, this news to and makes sense. I will have to track down the packing you mentioned.
thank you and everyone for their help.

Some food for thought:

1) A 1928 1 ton in good working order with a 5.43 rear end should not have any issues reaching/maintaining 30 MPH on level ground. If you really push it, you should be able to reach 40, maybe even 45 mph max speed (before installing an overdrive, fastest I ever went was 42 MPH).

2) Do you have a thermostat installed and if so, do you know that it's working?

3) Is the water pump in good shape/does it have the pump baffle installed?

4) Does the water level drop substantially after running it? (I once had a leaky head gasket that leaked water into the combustion chamber causing it to run out of water and overheat)