electric water pump for my eg33

[subarvair]

I know there is a huge thread on overheating which I read a lot when building my eg33 for a mid engine project. The changes I made were to move the thermostat from the inlet to the return side of the engine water system and increased the inlet fitting to 1.75" and am running 1.75 inlet hose to the radiator which is in the front of the car(about an 8' run). The return to the radiator is all 1.5".
With 180* thermostat, the engine runs for about 4 min and then overheats with an airlock in the engine. I have bled the system several different ways with the same result. I even hooked up the garden hose and forced water to the pump. I have pressure tested the system-there are no leaks.
Seems to me the waterpump can not suck water in the volume it needs because of the distance to the radiator and that what is needed is an electric pump at the radiator to push the inlet water to the engine water pump. I guess the flow would need to be at least 30 g/min.
Has anyone done this and did it solve any problems? What capacity pump was used?
Do you guys think this would solve the problem.
Mike

[oab_au]

Originally Posted by subarvair

I know there is a huge thread on overheating which I read a lot when building my eg33 for a mid engine project. The changes I made were to move the thermostat from the inlet to the return side of the engine water system and increased the inlet fitting to 1.75" and am running 1.75 inlet hose to the radiator which is in the front of the car(about an 8' run). The return to the radiator is all 1.5".
With 180* thermostat, the engine runs for about 4 min and then overheats with an airlock in the engine. I have bled the system several different ways with the same result. I even hooked up the garden hose and forced water to the pump. I have pressure tested the system-there are no leaks.
Seems to me the waterpump can not suck water in the volume it needs because of the distance to the radiator and that what is needed is an electric pump at the radiator to push the inlet water to the engine water pump. I guess the flow would need to be at least 30 g/min.
Has anyone done this and did it solve any problems? What capacity pump was used?
Do you guys think this would solve the problem.
Mike

With the thermostat in the top hose, there is no flow to heat it up to open. The pump is just circulating the water around the two bypasses, but not flowing it across the thermostat.

Harvey.

[Tireiron]

Yes, make sure with the thermostat in the upper hose that 1. it is close to the engine, not out by the radiator and 2. drill 2 1/8th inch holes in the thermostat plate to allow some flow even when it is closed to allow air to pass and to allow the hot water to reach the core and open it.

[subarvair]

When I welded in the inline thermostat housing, I plumbed a T just before the thermostat for a bleeder valve and a circulation hose that is connected to one of the circulation outlets on the pump. That allows me to bleed out the air and should also give me the circulation needed to open the thermostat. I should have taken a picture. Drilling the hole makes sense.
Thanks for the input.
Mike

[Tireiron]

Yea I should have taken a picture when I did mine. But I just put 2 small 1/8th inch holes in the flat plate of the thermostat. 1 on each side of the main central bulk just to allow flow to pass over the copper core. It still keeps a good restriction in the line so the pump pulls through the other bypass lines before it opens up allowing the coolant to circulate around the engine properly.

[dynomatt]

Dumb question, but would you need a thermostat with an electric pump? Only run the pump when water temperature gets to x degrees?

Thermostats exist because you can't stop a mechanical pump running?