David Leonard

The Rotary Roster:

http://members.aol.com/_ht_a/rotaryroster/index.html

Regarding cooling:  A.  The AN-16 should be plenty and not a part of the problem  B:  Don't know on this one but I would presume the pump would be a bit less efficient if running backwards - perhaps not enough to cause these types of problems, but on theother hand it wouldn't be helping. C: Could be I suppose, but I doubt it. Hard to say about the rest. 

Dave, a possibility that might account for the symptoms you are seeing is air trapped in the cooling system.  If your coolant is getting hot enough to boil but your radiators are only luke warm, then entrapped air could account for many of the symptoms you are seeing.  In my system, you can feel the sides of the radiator tanks and determine how much coolant is in the radiator.  Its hot where the coolant is and only warm to cool where it has not reached.  Typically on a refill of the coolant system only 2/3 of the radiator is initially filled with coolant.  It takes me 2-3 runs around >3000 rpm to flush the air out.

Fill up your header tank, run the engine at 3000-4000 rpm for 30 sec or so and then see if the level of fluid in your tank has gone down or remains the same.  If it goes down (replaced by air) then you have air in your system and I would continue this until the coolant level does not change.  Only thing I can think to advise you to try.

 

Ed Anderson