Autopsy of Broken "B" Engine

[bavArian]

Originally Posted by AzBob

Sorry, Ford did advertise the Model A capable of 55 to 65 MPH.

As said above, that's the top speed. Even some engines that were produced 50 years after the A were not able to sustain top speed for longer periods of time without taking damage. I would not exceed 50 mph for longer periods with an unmodified A/B engine.
That's part of the reason why I chose an A as my first antique actually. I wanted to be able to cruise at 80 kph / 50 mph without modifying a lot on the engine / car.