Porsche’s brilliant and immortal 356 Speedster has become one of the most collectable sports cars in history, but even in that select group—barely 4,000 were built over five years—the most exotic were the handful powered by the complex four-cam engine designed by a young factory engineer named Dr.

Ernst Führmann in his spare time.

Führmann’s masterpiece, an alloy-cased, double-overhead-camshaft engine with a roller-bearing crankshaft, was designed as a full-on racing powerplant.

It utilized dry-sump lubrication and dual ignition, with a pair of distributors being driven off the intake cams and a pair of switches on the dashboard allowing for individual testing of the twin coils.

The “Four-Cam,” as it is popularly referred to today, first appeared in the company’s mid-engine 550 Spyders of the early 1950s.

Developing about 110 horsepower in racing tune, roughly twice the output of the company’s similarly sized pushrod engines, this intriguing 1.5-liter powerplant would take on the ...