The Mechanical mind

Smokey Yunick’s career was legendary, spanning groundbreaking work with Hudson, Ford, and General Motors. More than an innovator, Smokey was a force of nature—known for bold ideas and relentless pursuit of performance. In 1991, when Duncalf set out to design the “ideal engine,” he turned to Smokey for guidance. 

While Professor Oppenheim had spent his life defining what needed to change in combustion and its environment, Smokey was uniquely qualified to show how to over come mechanical issues.  Which led to the first question Duncalf put to him.

Several engineers were concerned about possible failure because of the high pressure being placed on the small contact area of between the cam and the roller bearing followers.  Smokey explained away that problem.  He explained that oil instantly become highly viscous like a solid or a highly viscous plastic at such points of high pressure.  Even in fast running machines this thin crushed oil acts like a cushion between the two hard surfaces.  He thought the natural oil mist in the cam case may be sufficient to keep everything oiled as long as a quality oil was used.

Another issue was what he thought the dynamic produced by the cam profile should be?  He had the thought out answer the next day, a constant acceleration cam on both ends of he stroke.

It not only proved to greatly increase the efficiency of the spark ignition two-stroke version, but also promises to make managing the HCCI version much easier to accomplish. Smokey’s obsession with reclaiming waste heat and improving fuel economy directly shaped the Rad Cam engine. His recommendations—such as thermal coated aluminum pistons and and stainless steel heads with insulated coatings—became integral to its internal cooling system of the final design. More than his technical brilliance, it was his fierce, unwavering belief in the project that inspired the team. As one colleague recalled: “When Smokey believed in you, you had no choice but to rise to it.