In the offshore powerboat BBC, we have limited control over mass (the “m” term above). Given that, we must maximize frequency by optimizing stiffness, k
|
The first lesson in valvetrain is that it’s all about frequency. The frequency of any system is proportional to the square root of the stiffness divided by the mass. In pushrod engines, frequency is a challenge because the valves and the parts that move them are big and heavy. Drag racers have the option of using titanium valves to save weight. They can do this because the cycles are low and the temperatures are not sustained for long, pretty much the opposite of what happens in a boat. So, we’re stuck with steel and superalloy valves. We of course want to maximize our valvetrain frequency, so with mass mostly off the table (with a few areas to explore), we turn to maximizing stiffness. We can talk about how just to go about that in a later discussion. |
