A YouTuber's homebrew "Freevalve" system is going in a Miata.
You may recall that a few weeks ago, we reported on one intrepid DIYer who had made his own camless "Freevalve"-type valvetrain on a small single-cylinder Harbor Freight motor.
Well, things have escalated, and while Wesley Kagan's initial attempt at implementing his homebrew camless valvetrain was far from perfect, the inventive tinkerer already reckons he's just about ready for the big leagues: installing his creation on a four-cylinder Mazda MX-5 Miata motor. With a badly warped 1.8-liter Miata cylinder head procured from the junkyard, Wesley has devised a contraption to actuate all 16 intake and exhaust valves independently using pneumatic pressure.
Wesley's latest video doesn't give us a chance to see his brilliant 16-valve camless valvetrain in action; sadly, the solenoids and pistons he's chosen for this iteration are backordered. Instead, he provides us with a thorough walkthrough on all the moving parts that will constitute his newest homebrew "Freevalve" system, and it's truly impressive.
The biggest change - apart from the added complexity - is Wesley's move to incorporate double-acting pneumatic cylinders, which can use air pressure not just to open each valve, but to close them as well. In theory, this should provide much more control over the motion of each valve and remove the need for valve springs.
In practice, Wesley is leaving the valve springs in place so that if any of his pneumatic actuators should fail, the valve is still pulled close so that it doesn't contact the piston.
It's worth noting that if Wesley manages to get this system working, it will technically be more complex than Koenigsegg's first-ever production Freevalve implementation - at least in terms of cylinder and valve count. The 2.0L "Tiny Friendly Giant" engine that will provide motivation for the Koenigsegg Gemera is only a 12-valve three-cylinder. Granted, it doesn't seem as though Wesley's system is aiming for independent control for each intake or each exhaust valve on a single cylinder.
Even still, if this thing actually works, we imagine he'll have a ton of Miata owners knocking at his door to ask for his services.