MAGRED02

I have a 66 427-390hp that keeps overheating. The engine was professionally machined and rebuilt, i have a new dewitts radiator in it, rebuilt water pump and i took up a notch on the fan clutch, and i am not running a front plate. I am running 50/50 antifreeze and also "water wetter". None of this helps on hot days or if i am stuck in traffic. The rad usually winds up peeing all over the ground. Any suggestions out there?

BarryK

to help diagnose the problem does it puke coolant when it overheats?
have you confirmed the overheating temps with an IR temp gun or just the temp gauge?

if it's really overheating, does it do it in all driving situations or only at slow speeds and idle or only highway driving, or all the time in all conditions?

Has it had this problem ever since the motor was rebuilt or has it started recently?

Bluestripe67

Many other elements of this subject are captured in the "sticky" threads at the top of the page. Very helpful info. Dennis

midyearvette

i wouls suspect the re built water pump if the ir gun confirms the readings, if readings are ok....look at the rad cap to be sure it is for an older application....

DansYellow66

You need to tell us about your initial timing setting and how your vacuum advance is set up. Since tuning in my vacuum advance on my BB motor years ago with a vac can that would work with low engine vacuum and with full vacuum (not ported) my car barely warms up to the first mark on the gage. And that's on a calibrated gage and checking the temps with an IR gun. Engine timing may not be everything with getting these motors to run - but it's a major factor.

kenba

I will tell you none of the other craps works, Get a 170 degree fan clutch if you are sure that the rad,waterpump, ETC are working it's the repo fan clutch. BEEN THERE & DONE THAT! My car would be fine when it was cool or on the open road but when it was hot or at a stop light the temp. would go up & not recover.
KEN