MTFCA Forum

The question of having a water pump on a Model T Ford was answered in the Ford Times May 15, 1909. That date issued in the use of the Gravity or Thermo-syphon system.

According to the author, writing for Henry, made the statement that the cooling with a water pump was regulated by the speed of the motor. The faster the motor turned the faster the water moved with a pump. With a thermo system the heat of the motor regulated the cooling of the engine. The thermo system takes into account the weather (atmospheric pressure) On a hot day the cooling system water moves faster than on a cool day. See attached article.

Let it be noted, that when the Model T was introduced in 1908 (15 October) Henry's ad department listed 44 Model T Talking Points. Two points on cooling included that the engine was cooled by a gear driven centrifugal pump and a gear driven Fan. Meaning that there were no belts to slip.

By 1915, Ford in the Ford Times carried an advertisement in their pages on the benefits of an add on an aftermarket water pump to aid in the cooling of a Model T Ford motor.

Ford didn’t usually make mistakes in their “Ford Times” publications, but in the diagram in the article you posted, the illustrator has the water direction arrows pointing in the wrong direction. I’m surprised this mistake made it past the proof readers, unless, in 1909, the thermo-siphon system was not fully understood by the writers. Actually, the hot water rises and flows from the water jacket into the radiator then flows downward through the radiator tubes and is cooled by the fan and wind blowing through the radiator. You can see this for yourself if you take off your radiator cap while the engine is running to see the water flowing into the radiator from the engine. I have attached a correct diagram. Jim Patrick

As I read the thermo-syphon copy it's unclear whether the writer understood the system. It's very clear that the illustrator didn't.