I put a 195 degree thermostat in my 305 engine. It works good but when I shut the engine off it goes up to 215 degrees. Should I put a 180 in it?

Is 215 degrees too hot?

I live in NC

 

215 is not too hot. Of course the sensor will heat up right after the engine shuts down because the water isn't circulating anymore.

 

Thank you!

 

Thermostats restrict flow to bring an engine up to operating temperature and to keep the temperature from going below that during operation. Once it's open, it's open and the temperature is free to climb higher. A thermostat can't keep the engine from getting hotter unless it's stuck closed.

When the engine is running, it's the water pump and rad that have to keep the temperature from going too high.

A pressurized rad cap raises the boiling point of the coolant. Water will boil at 212F when not under pressure. Put it under 15 PSI and it won't boil until around 230F

Decades ago, a 180* thermostat was normal. With newer modern cars, they're designed to run hotter to reduce emissions so they all use a 195 thermostat. Engines running up to 215* is normal.

As mentioned above, shutting the engine off and the temperature increases it's because there is no coolant flow and heat rises to where the temp sensor is. If you start the engine and the temp drops back down then everything is normal.

 

AlkyIROC, Thank you for the very detailed information. I'm going to leave the 195 in it.

 

There is a lot of info out here and on the web about running lower temp thermostats and using other methods to help keep the car running at a good temp. You may want to google around and see what people are saying.

 

these cars came with 195* thermostats in them so I'd leave it, as long as its not overheating while driving then you'll be fine.