How to Get an Engine to Rev to 9000 RPM Without Blowing It Up (2024)

High-revving engines are great. They sound like nothing else on the road and fill you with immense joy when taken to redline. But, how do you design an engine spin up like crazy without blowing up? Jason Fenske over at Engineering Explained has the answer.

When talking about engine speeds, you need to first be aware of average piston speed, which is a function of stroke times two and RPM, divided by 60. Fenske notes that in internal-combustion engines, average piston speeds rarely exceed 60 mph, and aren't all that different in high- or low-revving engines. For a high-revving engine, you want a short stroke, since it means each piston will travel a shorter distance to reach that ideal average speed.

But how do you do this without causing damage? For starters, you need low reciprocating mass, which is why cars like the S2000 and the Porsche 911 GT3 use forged aluminum pistons. Rotary engines are also known for revving high, and that's because in eschewing pistons altogether, they don't have any reciprocating mass, just rotational mass. You also need lots of air, which is why the Honda S2000 employs variable lift on its intake valves.

But why would you want a high-revving engine in the first place? Power! As Fenske notes, horsepower is a function of torque times RPM, so the more revs you have, the more power you get. It's that simple.

But of course, you should watch Fenske's video for an even more in-depth explanation. And when you're done, go search for videos of 911 GT3s, S2000s, and other high-revving cars for some audio delight.