Ok still having issue at getting hot at highway speeds. So far tried 1. New aluminum radiator with 2400 cfm electric fan also tried the Original radiator with the electric fan 2. Checked both radiators both are clear not blocked 3. 165 thermastat 4. Ran with the AC on and Off still get up 230 plus at the front of the passenger head 5. Put spring in lower hose 6. Added another temp gauge to verify current gauge. There is about 15 degrees difference from driver rear head back the front of passenger for temp thermal couple location 7. New rebuild water pump 8. Reset the timing 9. Made sure the condenser was no more then 3/8 off the radiator for Gap This engine has all new gaskets, block was cleaned when heads where off. I know the only thing I didn’t try was a mechanical fan with a shroud. I have not found anyone with a after market AC unit on one to see if they have their engine running at 190 or less. Just seeing if there is any other ideas. Thanks Jeff
is the heat riser in the exhaust manifold open. did you try a different thermostat. head gaskets ? cracked head ?
First off you do not need a fan at speeds above 30 mph, in fact if the fans are too close to the rad and or they have too many blades all they will serve to do is block needed airflow from passing thru the rad core at road speed. Is your vacuum advance working ? At times of part throttle cruising the mixture is lean and needs more timing to burn fast and not create extra heat yet no additional power! At part throttle cruse you should have 48 degrees of total timing. What's the motors cranking compression? If it's low due to a shot timing chain , or too much Cam then the motor simply can't pump out all the Exh / heat that it needs to.
I removed the heat riser from the exhaust. Had a 180 and went to A 165 thermastat new head gaskets, no cracks in the head I tried the fan off above 30 and still got hot, but the fan shroud covers the radiator besides where the fan is which is 16". The fan is about 1" away. This has the Pertronix electronics in the distributor OK I can check the timing again Not sure on the compression Checked the chain when I had it apart and it was good
Make sure your Dynaflow linkage is functioning if it's in high stall all the time that will make lots of transmission heat,in turn raising coolant temp quite a bit.
With aluminum radiators you want larger tubing and fewer rows, these provide better cooling capacity. That shroud also looks like it blocks a lot of the surface area of the radiator? If the timing has been verified including the advance mechanisms. I would try removing the shroud and rolling around at speed (over 40MPH).
Is your fan/shroud on front or back of your radiator? (I realize the (stock) image shows the fan/shroud on the back.)
The thermostat controls minimum temperature and has nothing to do with max temperature unless it's stuck closed
To be sure ... you are positive that the system is full of coolant(?) Try removing the thermostat Pressure test the system Cap in good condition?
Have you used an infrared thermometer to check temp in and out of rad. This will tell what the rad is doing. Also can check each cylinder to see if somethings up from ea. cylinder and side to side.
I have checked the fan rotation and it is correct. Yes it was but I will make sure I bleed it this time when I refill it. I have checked the temp with a laser thermometer. The temp by the front head where the gauge is about what the gauge is reading. the upper hose was a littler cooler then that area.
