Miata Koensegg freevalve build

[Belgian1979]

Interesting what this guy is trying to achieve.

https://www.thedrive.com/news/38090/diy ... ight-motor

I understand that after testing he would like to build this onto a Miata head.

[HDBD]

I hate to be the skeptic especially when this guy is very talented but the ability of those devices to open and close with needed response time at higher rpms might impose a hardware issue with no software fix.

[Belgian1979]

Yes, I personally like the Fiat airvalve system better. However they don't offer it anymore. No explanation why though.

[Kevin Johnson]

Yes, I personally like the Fiat airvalve system better. However they don't offer it anymore. No explanation why though.

https://patentimages.storage.googleapis ... 910599.pdf

The above is a patent to help correct problems with the MultiAir system. If you read the patent you will note that engine oil is the preferred hydraulic fluid.* The fatal assumption is that engine oil in situ remains incompressible** and therefore essentially providing simultaneity of actuation. Sadly, this is not the case.

Porsche also had issues with using engine oil as a hydraulic fluid.

OEMs are not going to come right out and say what the engineering problems are but if you follow their patents (read "white papers") then you should be able to deduce the issues. Porsche subsequently used deaeration techniques to improve their difficulties while FIAT appears to choose electronic means.

Just my opinion, of course.

* Column 4, lines 9-16.

** [My emphasis]

The beauty of Fiat’s “Multiair” system is its simplicity; it essentially achieves what Valvetronic does by using hydraulic fluid running through narrow passages connecting the intake valves and the camshaft so the two can be decoupled. This system is modulated by an electronically controlled solenoid, and there are effectively two modes: When the solenoid is closed, the incompressible hydraulic fluid transmits the intake-cam lobe’s motion to the valve, as in a traditional engine.

[Belgian1979]

Thanks.