You've got it right, carlb.

2 hoses off the expansion tank - one T'd into the lower rad hose so I can fill the radiator from the expansion tank. The other is from under the cap to the overflow tank. Obviously this second one would only come in to play if the car is overheating...

The engine steam vent is a short hose that runs to the very top of the radiator on the driver side.

Originally, I had that steam vent running back to the expansion tank. It's working better and makes more sense in the current configuration.

Cheers,

Dean

 

News I can use. Thanks Dean!

 

If I recall I remember hearing you do not want to plug the heater hos connections but rather get a U shaped hose so that it can circulate. I'll have to look for the thread about it but it said something along the lines of helping the circulation of the coolant.

 

I know this is an OLD thread, but it's been revived alot. I'm considering using something similar to diagram #3 in my swap. My reservoir is the highest point in my cooling system. I'm running my stock Volvo pressurized reservoir, and stock Volvo radiator. Cap is 15 PSI like a stock GM truck cap. This seems like the most logical way to plumb this, I don't see how the steam could be re-introduced into the engine when it's ran into the reservoir. Wouldn't the steam/air bubbles separate at that point, with any fluids going to the bottom of the reservoir, and steam staying at the top?

 

Your logic is sound. But... I did have mine plumbed exactly as you are describing - with the steam line going only to the surge tank. I found that the hot water (that separates from the steam) in the surge tank was allowed to essentially bypass the radiator and flow directly back in to the engine without cooling. Mine worked better with the steam line plumbed directly to the top of the radiator.

If you don't have an easy way to plumb the steam line in to the radiator, it's worth plumbing as you describe and giving it a try. Mine is a pure racing application and has a different sort of cooling need.

BTW - a small infrared thermometer is very handy in diagnosing cooling issues. You can quickly see how hot the different hoses are getting to see where your heat is going.

Cheers,

Dean

 

Thanks for sharing that bit of information.
Never knew this.

Now I'm going to put more thought into this part of the cooling system.

 

interesting to read...

 

Very old thread, but good information. I did have a question. If you did not have the port on the radiator, but rather a standard overflow port that is blocked by the cap until cap pressure is exceeded, how would you run the system?

 

You would run a standard non-pressurized overflow bottle.

My question is, I don't have a catch can/overflow that the expansion tank vents to, with a standard "closed" radiator cap won't the system suck air when cooling because of the vacuum?

 

If your system is working right you shouldn't have any coolant being pushed out from the expansion tank. There should be enough air space in there to allow expansion of the coolant when the engine warms up and then when it cools down any air drawn back in will stay in the tank and not get into the rest of the coolant system.

 

http://www.oreillyauto.com/site/c/de...ailabilityTab_

I'm going to run the bottom hose off The tank to this in my lower rad hose. Should work well.

 

Yes, I know that this is an old thread, but I've been trying to understand how to correctly set up my cooling system with an expansion tank once I get a radiator. (It doesn't help that all of the images that once populated this thread appear to be gone...) I definitely want the coolant to be drawn back in to the radiator/cooling system after it gets pushed out to the expansion tank.

Since the thread doesn't seem to have any images, I went out & searched for some that illustrated what's being discussed here, & here are the only two good images that I found. For those of you more-knowledgeable on this topic than I am, do these appear to be correct and/or a good/workable way to plumb in the expansion tank?? Thanks in advance.

If memory serves, this first setup is from either a low-end Nissan or Toyota Corolla...


and the second one is from a Focus ST.

 

Yessir--if you did it the way these images show, youd be good to go.

Great old thread with good info, just wish the pictures were still there...

 

Meanwhile..... 6 years lateur.....