07/10/2026
At the 1965 Oakland Roadster Show, a '23 Ford T-bucket powered by a Buick Nailhead V8 had no distributor. No plug wires fanning out from a cap. One coil-like component at the front of the engine. One single wire feeding all eight spark plugs. Every plug fired continuously, all the time, as long as the ignition was on. Hot Rod magazine ran the photo in June 1965. Readers wrote in insisting it was impossible. Ten months later, Hot Rod ran a follow-up article titled "It Won't Work!" and then explained exactly how it did. The car won the show's engineering award.
The system was called the Kaehni ignition, patented by Frank J. Kaehni (US Patent 2,968,296, filed March 1958, granted January 1961) and developed for the Economy Engine Company of Youngstown, Ohio, which built stationary gas engines for the petroleum industry. Charles Miller, the T-bucket's builder and an R&D engineer at Economy, adapted the industrial system for his show car. A solid-state transistorized oscillator circuit running at 1.2 kHz triggered an inductive coil that stepped up 12-volt battery power to approximately 45,000 volts at the plug gaps. All eight plugs sparked continuously, hundreds of times per second. No timing. No advance curve. No mechanical wear from points or a rotor.
The trick: only the cylinder on its compression stroke has sufficient fuel, air, and pressure for the spark to ignite the mixture. The other seven cylinders are on intake, exhaust, or power strokes, where the spark fires harmlessly into either fresh air, exhaust gas, or already-burning mixture. The principle is identical to waste-spark ignition, used decades later in the Buick 3800 V6 and Harley-Davidson four-stroke twins, except the Kaehni system took it to the extreme by wasting seven sparks instead of one. A modified cylinder head with a small prechamber housing the spark plug improved ignition reliability and allowed crude timing adjustments by altering chamber geometry.
It worked. It won an award. It never went into production. The inability to precisely control ignition timing, the accelerated spark plug wear from continuous firing, and the impracticality of the prechamber head modification made it a brilliant engineering curiosity with no commercial future. The Economy Engine Company survives today as Altronic, LLC, a unit of Hoerbiger Holding, still supplying ignition systems for large industrial gas engines. The Kaehni ignition lives on in patent databases, a single issue of Hot Rod magazine, and the memory of every hot rodder who looked at that photo in 1965 and said "that can't possibly work."
