OUCH, I went down the freeway at 60 mph in 5th gear and got the coolant temp down to 155F or 70C!!!!!!!!!!!!!!!!!!!! The plexiglass I put over the
oil cooler is working like a champ. I guess I will get some more and cover the bottm 1/3 of the radiator and see what happens. Optimuim temp for engine life is 85C to 100C. Thermostat is for all practical purpose usefull, I had no idea the bypass provides that much coolant.