Stan Galat posted:IaM-Ray posted:Those are usually installed at the high point. Is there a high point in our system? Maybe near the engine but the flow of the coolant at that area might affect it. What say you kind Sir, Stan ?
These would be completely unaffected by flow, as a hyronic heating system has at least as much flow as your engine.
A vent is always in the high point of a system, or at a localized high-point where air can be trapped. It's a good idea to put a vent at every one of these points in a hydronic heating system, and I'd assume if the cooling system on a Subaru is convoluted with any traps, vents in those places would be a good idea. If the heads are where coolant is trapped, I wonder about drilling and tapping the heads for coin vents. 1/8" NPT is pretty stinking little.
The heads are not where the air gets trapped in a Soob conversion....in my case at least ...it was always in the hoses to the rad and back or whatever. Or in my case one high spot was the top of the coolant manifold. Other builders won't have this high spot I mention as they have a filler neck with a rad cap on top of it welded onto the top of the coolant manifold.
I did look as much as I could at a water cooled IM at Carlilse years ago but you cannot see much. The coolant hoses they use are Marine style wire reinforced rubber coolant hoses, very heavy duty and they go in a somewhat convoluted manner from back to front and back again, up and down several times.
Because I'm not smart enough to emulate that system I just dumbed my system down to something I was capable of dealing with.
Those are nice little bleeders Stan showed. Not knowing any better, I used several like the ones Ray shows which are just basic radiator drain valves.
Hope you can find the high spots in the hoses, Ray. You'll need to find every high spot, not just the highest.