Re: cooling water

Posted by TxGoat On 2023/6/23 7:30:54

The '37 120 cooling system is handicapped by reason of having an atmospheric, non-pressurized cooling system and a relatively crude water pump using bushings and soft packing instead of ball bearings and a mechanical seal.

Lack of pressurization limits operating temperature and allows atmospheric oxygen continual access to the system, and the soft packing is prone to leaking coolant out and allowing air to be sucked in. The bushings will wear, causing shaft mis-alignment, and worn bushings make keeping the packing water and air tight very difficult.

A pump with this type packing will benefit from a good water pump lubricant.

Use of modern antifreeze (the green stuff) provides some lubricity, raises the coolant boiling point, serves as a wetting agent, and prevents oxygenation of the water, foaming, and corrosion. It works best at a 50/50 mix with clean water.

A car running with a slightly worn or loose water pump seal will suck air into the coolant at higher engine speeds, which is a very bad situation.

It promotes corrosion, dramatically reduces the cooling ability of the coolant, and can mimic boilover by increasing the volume of the coolant, thus forcing coolant out the radiator overflow.

It doesn't take much of this to cause actual severe overheating, with a high risk of steam pockets and cracked valve seats.

A very beneficial modification for a 120 or any car with a non-pressurized cooling system and a rag seal, plain-bushed water pump would be a radiator that was designed to run with at least some pressure and a ball or roller bearing water pump with a mechanical seal.