Mo valves, mo power
In a typical car engine, valves in the head open and close to allow air in and out of the combustion chamber. In their original iteration, such engines had one valve for intake and one for exhaust. Most newer engines have four valves, two for intake and two for exhaust. This is an example of Principle 1 – Segmentation, but what is the advantage of having more than one of each valve? Isn’t adding more components just asking for reliability problems and expense? After all, there’s only so much room in the head – what’s the point of adding more valves if they have to get smaller?
In this Engineering Explained video, Jason Fenske explains that the valve’s ability to let air in and out is proportional to the perimeter of the valves, not the area. Adding more valves substantially increases the perimeter even though the overall area of the valves stays about the same.
Sometimes you make something twice as big and find that not everything doubles. Some other property might square and cube.
A whale stays warm in arctic waters because it is huge – double the length of a whale and its surface area quadruples, but its inner volume goes up by a factor of eight. This low surface to volume ratio means that it loses heat to the frigid water slower.
What can we learn?
If you find yourself designing a system or process that simply won’t scale, what happens when you apply Segmentation?