The last time we looked in on the ambitious Wesley Kagan, he had managed to put Koenigsegg-style Freevalve engine tech into a lowly Harbor Freight Predator engine. The little engine ran, even if it had a few glitches to be ironed out. Now Kagan is taking his idea to the next level: He’s adapted Freevalve technology to a Miata four-cylinder.
For a quick recap, Freevalve dispenses with most of the mechanical components that open and close an engine’s valves. Instead of camshafts, followers, rocker arms and such, the valves are actuated with electromagnetic force.
Camless engines can be more efficient because their valves aren’t limited to the mechanics of camshafts. This enables them to be operated independently, and they can have customized lift and duration based on performance modes, fuel type or other parameters. This technology squeezes huge levels of efficiency and power from of a tiny engine. Kagan’s Harbor Freight engine build used an adaptation of this tech that moved the valves using pneumatic pressure. His end result ran but had no acceleration.
But it’s only natural to up the ante when doing such a mind-blowing project as this. So Kagan’s next effort is making his adaptation of Freevalve work in a Mazda Miata.
In his first Miata build, he adapted the custom work he used on the Harbor Freight engine for a junkyard Miata engine. One departure from the Harbor Freight build was that the Miata engine would use dual-acting pneumatic cylinders as opposed to the single-action cylinders of the previous engine.
But he didn’t just want do the same build to a junkyard Miata engine — he also wanted to improve on his design.
His original idea for a second version of his Freevalve adaptation would use electromagnets to actuate the valves. However, he felt electromagnets really weren’t up to the job, so he moved to using banks of solenoids. These would use a coil of wire and an armature, activated by a magnetic field under electrical current. As any mad scientist would do, he built a small model first.
After a successful test he got cracking into the Miata, starting with a better crankshaft position sensor and removing the engine’s head:
One of the coolest parts of the build is that Kagan does it in a manner that isn’t destructive to the Miata’s engine. This makes it so the build can be replicated by others or even reversed.
He’s making all of his work open source so others can do their own builds or improve upon his work. Kagan doesn’t want money to get in the way of technological advances, and he hopes others will do something awesome with it.
And it’s definitely awesome work as he not only got the Miata to start with the tech, but it runs and drives, too!
Check out his videos if you really want a deep dive into his wild tech. The fact that Kagan did this without the millions of dollars a major automaker has is frankly amazing!