Wrong place to ‘save weight’


Smoky Yunick, was famous for the quote ‘In 50 years of racing, from Baja to Bonnieville and from Daytona to Indy, I have seen a great many things, but I have never seen a blown motor win a race.’


Yunick was one of the great communicators of practial mechanical experience. I have read most of what he published, the copies of his books I own are all well worn, dog eared and full of notes in the margins. He was very clear on one point: most engine failures he had seen in modified engines came from one source: People trying to make parts lighter. To Yunick, the idea was simple; if it did not run on the last lap, you could not win, therefore any theoretical advantage of a lightend part wasn’t worth it. In airplanes, this is ten times as true.


Below is a picture of a Corvair piston. It is from an forced landing several years ago. An engine failure leading to a forced landing, which fortunately ended in no injuries and light damage to the aircraft.


I came across this souvineer cleaning up. It was in the #5 position of a flying motor when the #6 piston grenaded. There was little of #6 to tell the story, but #5 told the tale: Look at the wall thickness of the wrist pin. Next to it is a stock wrist pin, three times as thick. Neither the guy who owned the plane nor the guy who assembled the motor saw this comming. The pistons had been purchased years earlier, and then donated to another builder. Lost along the way was the fact they were ordered with incredibly light pins, made by a company which I later found out went bankrupt after a number of failures. The total weight savings in the engine had been less than a pound, but it had been the cause of the failure. The same plane is flying today with regular wrist pins.


When I wrote in my manual:

“Nothing you get in exchange for reliablity was a good trade, in aircraft weight isn’t the most importiant factor, reliablity is” 

I’m not speaking theoreticaly. I have a lots of souvineers in my hangar, where builders wanted to ‘try something better’. I have quite enough, avoid all temptation to add one to my collection. Thanks.



Smokey Yunick was one of the most colorful mechanical Americans of all time. He was both an aviator and a motorsports innovator of the first order. He was a prolific practical tester and technical writer. He lived in Daytona Beach for 50 years, and he was unusually accesible; when I was a student at Embry-Riddle I drove over to his shop on Beach Street to ask him a technical question. His Garage appeared closed, but his daughter had a pet shop next door, and if she thought your question was valid she would pick up a phone and say “Dad, can you come up front?” and the man himself would apear and walk you inside and answer your question. Yes, a man who designed and built cars that won both the Daytona and Indy 500 was generious like that. Take a minute and read his story: https://en.wikipedia.org/wiki/Smokey_Yunick




3 Replies to “Wrong place to ‘save weight’”

  1. The Wikipedia article, https://en.wikipedia.org/wiki/Smokey_Yunick , is excellent. It brought back memories of reading the “Say Smokey” column in Popular Science.

    It was there, I believe that I came across his disparaging term for chemical additives for engines that were hawked by the manufacturers that made all sorts of outlandish claims, “mouse milk”. Now, the name Mouse Milk is used for a lubricant. Aircraft Spruce even sells it.

    Piloting 50 missions over Europe in a B-17, as he did, was not for the faint of heart.

    His innovations for automobiles, and hilarious ways he made monkeys NASCAR officials and their rules show what an intelligent person he was.

    I note that he sold a 1968 Cameri to Don Yenko, who developed the Yenko Corvair Stinger. Jay Leno’s garage has a piece on the Corvair. Jay Leno’s Garage features the car on one video.

  2. William I have been a fan of smokey since the 50,s. Love his column in Hot Rod magazine called “The gospel From The Smoke”. His quotes are great but one I remember is when he talked about Bill france Jr.. He said “He is not smart enough to pour piss from a boot even if the instructions were on the heel”
    Your friend

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