Last week i completed the build and could make a "testrun" to see what happened.
The heater started up very well and i bleeded the air while the circulation-pump was running like you suggested loosening the clamp in top of the heater.
After 20min. the engine was heated up from 5 degrees to 65 degrees.To my suprise,the interiorheater (the original volvo one)wasn't becoming warm at all!
Today i found out the reason; the water-valve was not opening 100% while the dash-control-knob was shifted to 100%.
I was hoping to show you some details of the "manifold" i made of copper to route the coolant.
But i lost the pic's by a crashed memory-card.
So i took some pictures again on the street to show some details.
exhaust from the heater;
pipes made of 22mm steel, just the same as we use in Holland to transport the heating-water in house;
Heater-hose with T- for letting the heated coolant into the engine and car-heater.(T cannot be seen in mounted position, is right behind the hose.
And mounted;
Copper manifold, letting the coolant out of the engine, going to the heater.
Again,zoomed in,mounted in place.
Of course, i have to fasten the pipes and hoses in stead of Tiereps.But i was running out of time and needed the volvo this weekend.
I used a drawing from the volvo-documentation to explain the circuit of the coolant as it is right now.It's very easy to see where the coolant enters the engine; it's the T-pipe at the back of the cilinderhead.
The coolant leaves the engine at the back of the waterpump via a homemade manifold of copper.
If you take a look at the pics above, you will see the parts mentioned.
I didn't draw the details like valves etc. wich i installed for servicing the heater, it's just a rough drawing.....