Olds Mystery Hemi Back in the late '60s and early '70s, the Big Three were all heavily immersed in experimenting with all kinds of different engine concepts. This was the era of wild theories that sometimes led to full production pieces. For example, Olds built a very small 215ci all-aluminum V-8 engine and turbocharged it with 10.5:1 compression, requiring the use of a 50/50 blend of methanol and water the company called Turbo Rocket Fluid. (They should have called it Rocket Fuel!) Chevy dabbled with the turbocharged flat six in the Corvair, and Ford bolted a blow-through McCulloch supercharger (granddaddy of the Paxton supercharger) on the Y-block 312ci V-8 engine in the '57 Thunderbird. By the mid- to late '60s, Ford blitzed the performance world with the Single Over Head Cam (SOHC) 427 engine and tried to get it past NASCAR, but Bill France Sr. didn't bite. Chrysler fabbed up a single DOHC head for development as a response to Ford's Cammer, but it never made it out of the back room, although there are rumors that pieces still exist. Oldsmobile was also neck-deep in the experimental engine sandbox, which leads us to the photos we found in the CC archives. We haven't been able to dig up much on this engine other than it appears to be a pentroof-style chamber with centrally located spark plugs and four valves per cylinder. That's about as much as we know. We encourage you to enlighten us, but be prepared to reveal your sources. We'd really like to hear from someone in Olds engineering who worked on this engine. That would be cool. By Jeff Smith Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!