Just swapped the coolant in my radiator from water to antifreeze (always check the fit of the hoses with water - less mess). When running straight water, the Boyce always showed it running relatively cool - never climbed more than halfway up the gauge and NEVER went into the small circle at the SUMMER AVERAGE line. This afternoon, after putting in a 70/30 antifreeze mix, the temperature climbed into the bottom area of the small circle at the SUMMER AVERAGE line on the Boyce. Nothing else was changed on the vehicle. What am I missing?
That's normal. Pure water has better thermal transfer properties. What ever you add to it lowers its ability to pick up and shed heat so the engine will run a little hotter. A good radiator is essential.
Nothing - pure water is a more efficient coolant than a water/antifreeze mix (see link below), but of course with pure water you don't have protection from freezing or the higher boiling point that antifreeze provides. Also, antifreeze has corrosion inhibitors.
Take a hard look at the temperature extremes that your car might be exposed to in Massachusetts, and use enough (but no more) antifreeze than necessary to safely cover those conditions.
OK - brand new Berg's radiator, so that's not an issue. Usually run 50/50 for the vehicles in the garage, but this one will sit in a three-sided horse shed this winter, so I went with the 70/30. Aside from running high on the motometer, am I risking anything by going with a 70/30?
Not that I know of, should be fine.
Since its not directly said, I'll ask. When you say 70/30, I assume you are saying 70% antifreeze? As said above, glycol is not a very good coolant so keeping that to a minimum is best for cooling. 50/50 will not freeze until -26 F but maybe that's inadequate where you live?
70/30 is good to minus 84F. That's overkill for Massachusetts. The fact that the car will be sitting in an open shed all winter is irrelevant.
50/50 is good to minus 34F and should suffice in MA. I live in Minneapolis and that is all we need around here. Even if I lived in International Falls, I would only need a 60/40 mixture.
Never put more than 70% antifreeze - once you go past that point the freezing point spikes back up.
You'll get better gas mileage running hotter, and the plugs won't foul. I think most Ts run too cool.
Yes - was saying 70% antifreeze. Will most likely go back to the 50/50 mixture.
I always use 50/50, but I also drain the cars in the winter. That's the only 100% way to prevent not only freezing but also a leaking headgasket drooling into the engine for 4 months.