The Infinite Possibilities of Smokey Yunick
A Rush of Ideas ...
by Kevin Cameron
Tuesday, August 18, 2026
I am offended that Yunick’s lifetime of unending innovative achievement in auto racing is so often denigrated in terms of these mouth-flapping expressions: spirit of the rules, gray areas, borderline cheating. He set out in racing to use discoverable physical truths to make his cars win races. Becoming a B-17 pilot in WW II as he did required ground school as well as flight school – classroom time spent on aircraft behavior from the standpoint of aerodynamics. It was well-known that NACA facilities were in constant use, “cleaning up” aircraft designed by the big manufacturers – often resulting in 10-20 mph increases in top speed, with important fuel savings at cruise. (NACA – the National Advisory Committee for Aeronautics – became NASA in 1957).
Given those experiences, what could be more natural than to buy yarn and tape to do your own tuft studies of airflow over auto bodies? When the tufts lie down, the flow is attached and drag can be low. When they rise up and whip around, you know the flow there is separated and potentially loss-making. Is there flow separation aft of wheel openings? At door-to-body gaps? Under-body flows? What if the angle of this panel was changed just this little bit?
Multiply that one example by all the physical effects occurring as a race car operates. The possibilities of improvement are literally infinite.
Another essential element: a mind always occupied with analysis, with constructing the view from the mind’s eye. Yunick couldn’t help it – he wanted to know everything.
This makes me think of John Browning, whose mind’s eye visualized such a large fraction of the world’s firearm actions. His design process has been described as sitting quietly at a table, a finger of one hand slowly tapping, and modeling one after another solution to a problem in his mind’s eye. Once he had a solution, he would discuss it with his brother Ed, who would then turn ideas into testable hardware.
In a way, it was as though an aircraft airframe and engine specialist – highly intelligent but without degrees, went stock-car racing.
In the USAAF during the war, each aircraft was serviced by its own numerous ground crew. Was the engine crew chief sympathetic to machines? Or was it just a job? Yunick and his crew, like all combat personnel, wanted to return whole and alive from missions, and they knew that a substantial fraction of aircraft losses were caused by maintenance and manufacturing errors (think of the B-29, short-timing a new engine, which wrecked itself because one of its 18 cylinders had no piston). They became involved in the work on their aircraft. It was also well-known that when Gen. Curtis LeMay flew on a mission, he took care to fly with respected flight engineers. A top FE could make the difference between engines quitting on the return flight, and having plenty of fuel remaining at touch-down.
What is your perspective? Sanctioning bodies sell excitement and uncertainty, so a too-frequent winner must be put in his place. Builders know sponsors look for success (who watches the battle for last?), so they must try to win.
Imagine winning, then being DQ’d like one famous motorbike racer for having electric pencil scribbling found on your crankshaft (What did it say? ”PLEASE tell us!). A prominent sanctioning body had its infamous “briefcase rule,” saying that race direction will make any decision it believes necessary for the sport. Would you accept that philosophically and resolve to build an average car next time – a nice mid-packer? Or would you resolve to give them something challenging to think about? Time and again.
What is the spirit of the rules? Ask ten people to write out their opinion, then compare. What is a gray area? In a celebrated case, a new tech director in a bike series announced there would be “zero tolerance” for deviations from their expensive chassis jig, then discovered what everyone else had known for years – that stock chassis themselves had large deviations from the shortcomings of manufacturing. Manufacturers were known to drive the alignment pins out after welding a new chassis in an assembly jig, only to find that the chassis could not be put back into the jib because residual weld stress had pulled it so far out of alignment. In one factory I can think of, new chassis fresh from welding were “straightened” by big fellows with steel spud bars. Zero tolerance had to be dropped because the factories couldn’t achieve it. As with “spirit of the rules,” this left them with the question “Is this chassis out of alignment by accident, and therefore innocent? Or is there purpose behind this deviation, making it a crime?
This raises the question Yunick’s work always tested. What is stock? If it’s not defined in the rules, let’s run a little test.
Let’s run a bunch of them (for, like John Browning, Yunick had endless ideas).
Remember that, during the NR500 program, Honda engineer Shoichiro Irimajiri, waiting at a stop light on his way home from work, saw that two circles, joined into an oval would allow an oval-piston V4 to have the valve area of a V8.
How about we ease the trouble the air has, flowing past the wiper trough, then up the windshield to the angle where it joins the roof. Early flow separation there was obvious extra drag – like too high an angle-of-attack on final, feeling the buffet through the yoke. You can feel the flow separation move forward on the upper surface of the wing.
On the car, play with the gaps, shift the angles. Think like NACA engineers. Oops, now the front suspension has to be moved up in the structure – you guys hold that while I tack it.
With the test article ready, time for tuft studies. In the wind tunnel there are windows, but when you don’t have one, you put your photographers on an overpass to get snaps of your roof tuft arrays. Real information, not hunches.
When Yunick’s cars were mysteriously fast, officialdom were forced to have full-sized templates made to be sure race car shapes were as bad as stock - in detail.
Yunick wrote a column for Pop Sci for years. I remember one of them especially. He urged people not to expect too much from early production fuel injection systems, saying that while injectors were throwing fuel droplets ranging from 50-120 microns, the flow past the edge of a throttle butterfly in a conventional carburetor just off idle could do much better because the velocity there was much higher. The eventual response to this was the multi-hole injector.
Anyone remember the newly fuel-injected motorcycle whose oil level alarmed owners by rising? The cause was those big, air-penetrating 120 micron droplets, reaching the cylinder walls, then being scraped down into the crankcase by the oil scraper rings.
Yunick tried Inverted airfoils. They gave unreal corner grip. Still do. Reversed engine rotation, so acceleration torque transferred weight to the inside front tire (all engines in MotoGP now spin backward, but for a different reason). Let’s invent abrasive flow machining and pick up an alleged 50 hp from improved exhaust manifold flow. Rules don’t limit fuel line volume, so let’s make it free-flowing, say, five gallons-worth. How about weight offset? How about reverse-flow cooling? The P&W R-4360 engine, designed 1940, cooled the intake side of the head first rather than heating the intake side with air heated by the exhaust side. Result? A cooler and therefore denser charge, generating increased torque. Is there a moral aspect in design? Some people see good versus evil, but others see only wise versus unwise.
What about Yunick’s “hot vapor engine,” which was an early attempt to use the the ideas now given the name ‘HCCI” – homogeneous charge compression ignition?
Think of Tom Sifton, considering the big problem of flathead engines—cylinder distortion from the nearness of the exhaust port to the cylinder. We’re talking the 1950s here. Sifton cooled the pistons with oil jets, shooting up from the crankcase. Nearly all motorcycle engines today have piston cooling oil jets.
Shall we admire and reward innovation? Or are we happiest when we learn to think as others do? Having ideas can make you lonely.
Dean F. Adams
Smokey Yunick, in his work coveralls, sitting on the pit wall at Daytona in 1994. The legendary tuner would stop by the Daytona 200 every year to see old friends. Due to Smokey's, um, relationship with Daytona his pass would have to be requested from the highest levels of AMA Pro Racing and but was always grudgingly approved by DIS.
Multiply that one example by all the physical effects occurring as a race car operates. The possibilities of improvement are literally infinite.
Another essential element: a mind always occupied with analysis, with constructing the view from the mind’s eye. Yunick couldn’t help it – he wanted to know everything.
This makes me think of John Browning, whose mind’s eye visualized such a large fraction of the world’s firearm actions. His design process has been described as sitting quietly at a table, a finger of one hand slowly tapping, and modeling one after another solution to a problem in his mind’s eye. Once he had a solution, he would discuss it with his brother Ed, who would then turn ideas into testable hardware.
In a way, it was as though an aircraft airframe and engine specialist – highly intelligent but without degrees, went stock-car racing.
In the USAAF during the war, each aircraft was serviced by its own numerous ground crew. Was the engine crew chief sympathetic to machines? Or was it just a job? Yunick and his crew, like all combat personnel, wanted to return whole and alive from missions, and they knew that a substantial fraction of aircraft losses were caused by maintenance and manufacturing errors (think of the B-29, short-timing a new engine, which wrecked itself because one of its 18 cylinders had no piston). They became involved in the work on their aircraft. It was also well-known that when Gen. Curtis LeMay flew on a mission, he took care to fly with respected flight engineers. A top FE could make the difference between engines quitting on the return flight, and having plenty of fuel remaining at touch-down.
What is your perspective? Sanctioning bodies sell excitement and uncertainty, so a too-frequent winner must be put in his place. Builders know sponsors look for success (who watches the battle for last?), so they must try to win.
Imagine winning, then being DQ’d like one famous motorbike racer for having electric pencil scribbling found on your crankshaft (What did it say? ”PLEASE tell us!). A prominent sanctioning body had its infamous “briefcase rule,” saying that race direction will make any decision it believes necessary for the sport. Would you accept that philosophically and resolve to build an average car next time – a nice mid-packer? Or would you resolve to give them something challenging to think about? Time and again.
What is the spirit of the rules? Ask ten people to write out their opinion, then compare. What is a gray area? In a celebrated case, a new tech director in a bike series announced there would be “zero tolerance” for deviations from their expensive chassis jig, then discovered what everyone else had known for years – that stock chassis themselves had large deviations from the shortcomings of manufacturing. Manufacturers were known to drive the alignment pins out after welding a new chassis in an assembly jig, only to find that the chassis could not be put back into the jib because residual weld stress had pulled it so far out of alignment. In one factory I can think of, new chassis fresh from welding were “straightened” by big fellows with steel spud bars. Zero tolerance had to be dropped because the factories couldn’t achieve it. As with “spirit of the rules,” this left them with the question “Is this chassis out of alignment by accident, and therefore innocent? Or is there purpose behind this deviation, making it a crime?
This raises the question Yunick’s work always tested. What is stock? If it’s not defined in the rules, let’s run a little test.
Let’s run a bunch of them (for, like John Browning, Yunick had endless ideas).
Remember that, during the NR500 program, Honda engineer Shoichiro Irimajiri, waiting at a stop light on his way home from work, saw that two circles, joined into an oval would allow an oval-piston V4 to have the valve area of a V8.
How about we ease the trouble the air has, flowing past the wiper trough, then up the windshield to the angle where it joins the roof. Early flow separation there was obvious extra drag – like too high an angle-of-attack on final, feeling the buffet through the yoke. You can feel the flow separation move forward on the upper surface of the wing.
On the car, play with the gaps, shift the angles. Think like NACA engineers. Oops, now the front suspension has to be moved up in the structure – you guys hold that while I tack it.
With the test article ready, time for tuft studies. In the wind tunnel there are windows, but when you don’t have one, you put your photographers on an overpass to get snaps of your roof tuft arrays. Real information, not hunches.
When Yunick’s cars were mysteriously fast, officialdom were forced to have full-sized templates made to be sure race car shapes were as bad as stock - in detail.
Yunick wrote a column for Pop Sci for years. I remember one of them especially. He urged people not to expect too much from early production fuel injection systems, saying that while injectors were throwing fuel droplets ranging from 50-120 microns, the flow past the edge of a throttle butterfly in a conventional carburetor just off idle could do much better because the velocity there was much higher. The eventual response to this was the multi-hole injector.
Anyone remember the newly fuel-injected motorcycle whose oil level alarmed owners by rising? The cause was those big, air-penetrating 120 micron droplets, reaching the cylinder walls, then being scraped down into the crankcase by the oil scraper rings.
Yunick tried Inverted airfoils. They gave unreal corner grip. Still do. Reversed engine rotation, so acceleration torque transferred weight to the inside front tire (all engines in MotoGP now spin backward, but for a different reason). Let’s invent abrasive flow machining and pick up an alleged 50 hp from improved exhaust manifold flow. Rules don’t limit fuel line volume, so let’s make it free-flowing, say, five gallons-worth. How about weight offset? How about reverse-flow cooling? The P&W R-4360 engine, designed 1940, cooled the intake side of the head first rather than heating the intake side with air heated by the exhaust side. Result? A cooler and therefore denser charge, generating increased torque. Is there a moral aspect in design? Some people see good versus evil, but others see only wise versus unwise.
What about Yunick’s “hot vapor engine,” which was an early attempt to use the the ideas now given the name ‘HCCI” – homogeneous charge compression ignition?
Think of Tom Sifton, considering the big problem of flathead engines—cylinder distortion from the nearness of the exhaust port to the cylinder. We’re talking the 1950s here. Sifton cooled the pistons with oil jets, shooting up from the crankcase. Nearly all motorcycle engines today have piston cooling oil jets.
Shall we admire and reward innovation? Or are we happiest when we learn to think as others do? Having ideas can make you lonely.
— ends —
