Coolant tank design and corrosion

[Doug Kirby]

I purchased a Murphy level switch gauge for a coolant tank I plan to make over winter here in New Zealand for my 6BTA 250 hp engine, this is to replace the original 1990 coolant tank and expansion recovery bottle system. The coolant tank I plan to be about 12 litres capacity (a litre is approximately a quart), the normal tank level will be 50% full, so I will have 6 litres of draw down available and 6 litres of expansion capacity of which I have calculated I will use 1.26 litres of that 6 litres available from cold to normal operating temperature.

I was thinking of making the coolant tank from mild steel and figured that corrosion in the bottom half of the tank will be unlikely as it is permanently submerged in coolant but was wondering about corrosion in the upper half of the tank.

My questions are:-
1. Are there any flaws in the plan ?
2. Is corrosion going to be an issue in the upper half of the tank and if yes how can I prevent that ?

Thanks in advance, Doug

Topic

[Tony Athens]

Your plan sounds fine but not sure why you feel you need to run a 50%.. IMO, 80% would be better, but you may have a reason that I do not understand. Don’t worry about rust–Use good coolant . If on the engine be sure the mounting/bracketing is designed right. Use a 3/4″ ID make up line on the bottom, properly placed vent lines that feed the top, and a applicable pressure cap rating depending on the height of the coolant level above the engine..

Some pics attached.

[Author]

Replies