Hi there,
I am thinking for some time to make a system for flushing my car cooling system. One that is able to recirculate the flush compound. My car has motor oil in the cooling system due to a leaking headgasket. I do not want to flush it with a garden hose because the time the flush compound is in the system is really limited. Other products are meant to put in the cooling system and then drive the car around so the engine will heat up and detergents can do their work. The problem with this approach is when there is oil pressure the coolant continues to get contaminated because the leak is still there.
I plan to do this flush as a step in my headgasket replacement procedure. Below is the setup that I plan to use.
You might be thinking I am overthinking and/or overengineering this process of flushing the cooling system. I simply don’t want to listen to comments like that. Especially those where people tell me xyz is “not necessary”. I have thought about this for a while and I’ve decided I do want to make this recirculation system. However as I’m not experienced in fluid mechanics I would like to discus design aspects of this system.
Some thoughts about this setup:
1) The pump I plan to use is a 3-phase 370W semi open impeller pump, LEO ABK50. The 3-phase version allows for speed control with a VFD. I think I should be careful with ramping up the flow rate slowly because an obstruction might build up pressure quickly which can damage the cooling system part on the car.
2) I also read about cavitation. I have already planned to put the pump at a lower level than the reservoir / cooking pan as well as a smooth hose leading to the inlet port of the pump.
3) The regular water pump in the car also has an impeller. I don’t know if it would be possible to lift the timing belt of the water pump sprocket and then force flow along the water pump impeller. Otherwise I might get an old water pump from a salvage yard on which I remove the impeller myself.
4) As my car engine is made of aluminum, both the cylinder and the block. When the engine is cold I think a camping stove would be insufficient to heat up the engine coolant to about 60°С for the detergents to do their work. You know it is not some 100 mm diameter propane cylinder but more like 220 mm diameter cylinder. But still the amount of gas coming out of it is limited. Another thought is to do this flush as soon as possible after haven driven it.
I would be nice to have other people share their observations on those 4 thoughts I expressed. Maybe other things will come to your mind about this design. Please let me know.