Several different things or a combination of them can cause overheating.


1)        Letís start with cooling systems in the 30ís and 40ís. We ran zero pressure radiators, which meant when the water temperature reached 212 degrees, it started boiling. (This is assuming no glycol antifreeze was used)


On a warm day (80 degrees or higher) with several people in the car just going up a hill could overheat the engine.

The first thing to remedy this is to pressurize the system. For every pound of system pressure, the boiling point of water increases about 3 degrees. A 10 lb. Cap thereby raises the boiling point by 30 degrees. This alone would raise the boiling point of the water to 242 degrees. (212 plus 30)

When water (or coolant) boils, it creates steam pockets which causes damage like cracks.


2)       Henry Ford made about 25 million flathead V8ís. For the most part, they ran fair in stock form. Now the hot rod guys took the stock heads off and put on after market high compression aluminum heads. From then on many had overheating problems for two reasons.


Improper surface finishes on the deck surface of the heads are still a problem today. It was always thought that a bit of a rough finish on the gasket surface would help hold the gasket. Small lines from the flycutting tool do not help hold the gasket. They are escape routes that prevent the cooling system from being totally sealed.

Home    About the New Block    Finding a Useable Block    Oil Consumption    Oil Leaks    Lower End Strength    Big Bore    Overheating    Intake and Exhaust Ports    Questions and Answers    Submit a Question    Mark's Recommendations