I believe a lot of that depends on the engine build. Mine ran and made the top power at around 220 water temp. Also notice that when it is cool NASCAR will block off most of their air flow to get their engines up to around 220/230. I have ran mine that way as it came from the factory running that type of temperature and is 41 years old now. I can feel the drop in power when I run it in cold weather and the water isn't above 180.
Ron
