Flathead 8BA Thermostat Question

Looking at installing Stewart/RobertShaw high flow thermostats in my 8BA and my question is should I run the ones with or without bypass holes?
Thanks, Bill

 

I run regular off the shelf 180* thermostats with one 1/8 hole drilled in the flange. In 95* heat yesterday my flattie showed around 170 degrees after the thermostats opened up and stabilized.

 

I run no bypass hole and off the shelf t-stat, my car runs cool at 185 DEG all day even with this heat. I did put new water pumps on it, new rad and electric fan. Best money spent. Maybe the 5 speed helps too?

I have heard both side of the great "bypass" debate and from what I understand if you have a overheating problem don't look for a miracle in the thermostat department. My car was over heating before and it had the bypass hole, never made a difference. fixed all the other problems with my cars cooling system and now it stays cool all day, without a bypass hole. Hope this helps you out


Brent

 

The hole is there to give the air somewhere to go when you fill the system.

 

Thermostats are just to warm your engine up quicker and keep the temperature constant when running. The bypass holes are nice when refilling the system as you don't have to warm it up to finish filling it.
Butch