Plenty of fan!
Okay --- if the fan is RUNNING all the time -- it's going to cause blockage at cruising speeds when it's not needed at all....
A simple fan switch and relay -- such as this, or similar, would be all that is needed to add fan control. It simply shorts to GROUND when the temp reaches "X" -- you can buy these in various temp ranges.
http://www.summitracing.com/parts/sum-890017/overview/
Do you have Air Conditioning?? If so then it gets a little more complicated and you'd need a Trinary switch in the A/C system.
Stupid question -- but you said the thermostat is "new".... but hopefully it's not installed upside down? Did you have this issue and is that why a replacement thermostat??
ASSume the system was "Burped".... i.e., after filling -- the cap was left off the radiator -- until it opened and you could see hot water circulating in the radiator. Sometimes this can create a mess if you fill it too full as there can be air trapped and when the thermostat opens you get a big belch of water out of the radiator... so I always leave it low -- and add water after it's run a bit and the burping is all done.
Next up -- is -- once you get 'er back together -- measure at the thermostat housing. Also at the inlet hose and outlet hose. Also a couple places around the head to check for hot spots. You should have at least a 20* DROP in temp from the top of the radiator where the hot water comes in = to the bottom where it re-enters the pump. That will check for adequate flow in the radiator.
THEN after you've ruled out a cooling system malfunction --- LET'S DISCUSS where your
timing and timing curve is set -- and give us some details about that and the motor -- aluminum heads or not - big cam or not - initial timing - total timing - and springs used to set the curve -- then is it vacuum advance or not and has that been checked to see how much advance that's pulling in. And at what vacuum is it adding curve.
Do you have a dial back timing light??
