LT5 Cooling and Radiators

[Dynomite]

Originally Posted by secondchance

Frank,

I tried 3 1/8" holes 2 years ago. During the winter coolant temp refused to go above 153 degrees F. I was concerned with inability to boil off water build up in oil. Went to one 1/8" hole and recommended the same to Charlie.

A 1/8 inch hole in the thermostat flange has an area of .0123 square inches compared to an open (or partially open) thermostat (1/4 inch open and say 1.5 inch diameter) of 1.17 square inches.

I am not sure what .0123 square inches adds to the flow rate of an open thermostat? (maybe an increase of 1.18-1.17/1.17 or .85% (less than 1%)

I am also not sure what contribution a .0123 square inch hole creates in terms of flow rate through the radiator when the thermostat is otherwise closed. Or .0369 square inches with three 1/8 inch holes in the thermostat flange.