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Comment by keanebean86 | Hacker News Reader

What I want to try is replacing valves with electric iris mechanisms. The computer would signal the iris to open or close depending on the situation.

No more complicated variable valve stuff. Just hold the iris open longer. Also no more interference engines and timing chain/belt changes.

Iris: https://commons.m.wikimedia.org/wiki/File:Iris_Diaphragm.gif

Edit: fixed typo, added link to iris gif

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I don’t think an iris like that would last very long with the immense pressures in the cylinders. It makes way more sense to electronically control the valves themselves, like Koenigsegg is doing with their Freevalve tech, so you get the mechanical seal of the valve with the control of electronics.

I figured it was something like that. It would still be a fun experiment with a small engine.

It’s a good question, why is only fuel injection and ignition computer controlled? The intake and exhaust valves must also be solenoid controllable.

This exists, but it is very expensive. https://www.freevalve.com/freevalve-technology/

Swedish hypercar builder Koenigsegg has made a system like this, they call it FreeValve.

Their upcoming car called the Gemera will feature FreeValve, its 2.0L 4-cylinder is said to generate over 600HP. Though it must be said that this is a 1.5 million dollar car, so don't expect this kind of performance per displacement from other brands.

A guy on Youtube made his own version of freevalve, and got it to work on a Mazda Miata: https://www.youtube.com/watch?v=E9KJ_f7REGw

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