The Engine Swap Hall of Fame:
4-Rotor Mazda RX-7 FC Build
This build isn’t even done yet, but the engineering and fabrication is so stunning that I feel compelled to feature it.
The skinny? It’s custom-engineered, 2.6l, peripheral port, 4-rotor Wankel engine transplant into a 2nd generation (FC) Mazda RX-7. Every piece is so jewel-like that it’s difficult to know where to begin.
John Huijben, an engineer and machinist based in the Netherlands, decided on a bit of a whim to put this engine together in his spare time. In his words, it’s more of an engineering exercise than anything else, and not meant to be a part of a fully integrated car. Put another way, it isn’t remotely the most practical or sensible way to build a powerful RX-7, but Lord help me if it isn’t absolutely fascinating. My kind of project, in other words.
Here’s the shell: a basic Series 4 (’86-’88) RX-7, a touch rusty, stripped down the degree it’ll have to be to accept the engine.
One of the build thread’s highlights is the CAD work. Stunning exploded views precede almost every major update and illustrate the benefits of careful design over a less thought-out, more improvised approach to engine building.
The slide throttle in particular is a complete work of engineering art. Less restrictive than a conventional butterfly throttle, especially at WOT, its design and implementation are peerless.
The part of the 4-rotor build that takes the cake, though, has to be the custom eccentric shaft (a rotary’s equivalent of a crankshaft). Instead of mating two e-shafts from smaller, 2-rotor engines, Huijben decided to design and machine his own custom piece from a solid steel billet (shown at top in photo above). Given its precise balancing, oiling and harmonics requirements, it’s a tour de force of engineering.
I’ll definitely be keeping up with the build’s progress. Can’t wait to see it come to life for the first time!
H/t to Aaron for the link to the build. Thanks!
Editor’s note: This post is part of an ongoing series showcasing awesome engine swaps and builds. Read the other installments here: