Hi friends, I want to know if I have to drill or not a hole in my 180 stant thermostat. I read somewhere about drilling a small hole 1/8 or 1/16 in the thermostat to help it bypass and that helps the system pressure stabilise and the valve open easier. This hole also allows air pockets to move past the thermostat even when the thermostat is closed.... this is true? why the aftermarket dont have the hole? Which is the best measure hole 1/8 -1/16? I am confuse!
Everyone I've bought in the last 10 years comes with the hole in it already. If it didn't, I'd put it in. Lets the air out of the block when filling so you don't have hot spots. Will not have any negative effects. 1/8" is good enough - and place it at the 12 o'clock position.
You will notice in " Acornridgeman's " photo the hole has what's called a " jiggle pin ". What this does is to move around with the coolant flow to keep any dirt or rust from clogging the hole. The same can be done with a small cotter pin inserted after you drill your hole. I don't care how clean your cooling system is, there will always be a little bit of dirt and rust particles in it!
I read this from Stant site: My thermostat has a jiggle pin but the Stant thermostat doesn't. Will a Stant thermostat still work? Yes. Many thermostats have a “jiggle pin” that allows trapped air in the cooling system to pass through the thermostat and be released from the system. Some Stant thermostat do not use have a jiggle pin. These thermostats will have a "bleed notch” or other method of removing air from the system. Some thermostats also have a disk at the base that closes a bypass circuit inside the engine as it opens the radiator circuit. The mine doenst have that plate neither hole, neither jiggle pin! OH MY GOD! http://www.stant.com/Consumer-Products/Thermostats/ABCs-of-Thermostats http://www.stant.com/Consumer-Products/FAQs/#anchor16
The 6 cyl use an internal by-pass. When I went with an electric water pump I drilled three 1/8" holes in the t-stat for a by-pass
on any application, you always want to drill an 1/8 in. hole in the thermostat. I was taught this in my Engine performance class and I always do it with every car Ive owned....
