Radiator tips for 67 Dart with 440
That's a lot of blocked radiator it cruising speed.
Nice math, I like it.
To me it seems that this combo has multiple problems.
here is a quick test;
Get the engine up to 190 and idling, in the driveway hood up is OK. Turn the fans on hi.
This is an Idle-test.
If the temp does not fall: check the temperature difference at the thermostat house, versus where the water exits the rad at the lower hose spigot, on the metal tank is fine. You are looking for about a 30 degree difference.
If you get that, (at ~190* coolant temp) or close to it, then you don't need a different rad.
If you don't get close to that, first cool the rad off by spraying a fine mist of of water on it, until the engine temp comes down; if you have a paper airfilter, you may need to protect it from the fan spray.
So now we are on the hunt.
Here are the possibilities in order of probability;
*Lack of sufficient air-flow thru the rad,
*Lack of sufficient coolant flow thru the rad,
*Lack of sufficient thru-put by the waterpump,
*missing thermostat,
*Retarded ignition timing,
* Combustion gasses leaking into the cooling system,
* tight ring gaps.
Now, we already have a very good clue!
You said, car still gets hot at over 35mph. Assuming that's in Third gear with an automatic;That's a dead ringer for one (or more) of;
* lack of sufficient airflow thru the rad, or
* a plugged A/C condenser, or
* a collapsing lower hose, or
* combustion gasses leaking into the cooling system, or
* a severely restricted exhaust,
* with a possibility of the ring gaps butting.
Happy Hunting.
I forget, did anyone mention; lack of airflow? lol.
