I have been running a 1975 Lola 342 for about 7 years with my water thermostat pretty much stock except for about 4 1/8 holes drilled through it based of someones suggestion. I just removed all of the thermostat guts except for the outer ring based on another suggestion from someone else. The two times I have run the engine it seems to get hot faster than before. Both times I have run it it was stationary with fans blowing on the radiators. My question is what type of thermostat should I run. Also I just set up a separate overflow for just the coolant. Should that bottle be vented or air tight.
thanks
John