I stripped my 1725 engine and replaced the camshaft, checked everything and thoroughly cleaned the water galleries. The radiator was re-cored at the same time, and when all re-installed filled with 50/50 anti freeze and water. After just a couple of thousand miles the water is very rust coloured and dirty. Have I used the wrong type of anti freeze? Is there a strong recommendation of type for these engines with alloy heads?
It could be as a result of what was left in the heater matrix: a lot of debris sit in here, but cleaning them out can cause leaks! I always used Bluecol in 'the old days', but my mechanic mate preferred the green BMC-type stuff of the day. I now use one of the modern-type orange coloured ones in my car & haven't found any problems; but yes the water is still a bit rusty again even after a fairly major drain-off to do the head gasket. I always keep a 50/50 solution or even stronger to help keep corrosion at bay. Cheers. G
On the SAOC forum there is just posted that 1/3 of blue anti freeze plus 2/3 of distilled water is the solution to avoiding that this mixture is getting dirty. The poster has tested this on his Alpine for some time and it seems to work.
I tend to use distilled water (salvaged from my dehumidifier) for the engine cooling. Might be brown from the heater matrix, although I did quickly flush it out. I'll probably drain down again, and try again. Thanks Gents.