Okay, so last summer i kinda "Bit the Bullet" and put a front-mount radiator into my 1275LS. This one was from an Alfa 33? or Alfasud (Maybe it was infected by alfa-itis). It is a very large rad, almost the width of the Clubby 'grille' opening and it is about two inches taller, so it sits down a bit from the lower edge of the grille. This rad cooled an all alloy 1500cc, boxer twin-cam, twin Weber fed, go-fast (for its time) kinda car.
When used in the Alfa, the coolant flowed from the top right of the core, across to the bottom left. I had this changed to top right, to bottom right, using a plate in the side of the tank, then with Mini-sized necks and a core flush, and a little bit of patience, it all went in, with its factory Thermo-fan, too. Very neat and functional. All up $150. Bewdy.
However, it has never really worked 100%. Some days we could all go cruising during 35 degree heat and it would run as cool as the thermostat would let it (160*F). But somedays, it just wants to overheat, and not stay under control at all.
Now the car has a new motor, with 70hp at the wheels, all dyno'd up, so its not running lean or too far retarded, and the temp is even more tempramental, sometimes cool, but more often than not, too high for my liking.
Is the rad too big for the water pump? I have a high-volume (wide impeller) pump, but my cooling (or heating) issue is not consistent. Sometimes is good, Sometimes is bad. Do I need to have the flow changed back to just Left-to-right, as it is going too fast Left-to-right-to-left?
What could i be doing wrong? I have a top header-tank, with a bleed line to the top of the rad, as the core is lower than the thermostat housing, and all the air is out, but it gurgles when i turn the motor off. HELP!!! I have tried everything to my knowledge of cooling but to no reliable consequences.
I would prefer not to go back to the old side-mount, as i have had too many Minis with new or reco'd side mounts that still cook themselves.