Chevrolet "Stovebolt" Six
by Jack Nerad for Driving Today

The story of the Chevrolet "Stovebolt" Six is a classic tale of American competition. It pits the protégé versus the master in a battle for the hearts, the minds, and the wallets of millions, and it proves yet again that if you build a better mousetrap -- and let people know about it -- they will indeed beat a path to your door. In competing with the top motorcar brand of the era, the path was not always easy, but the stalwart souls at General Motors persevered when others said it could never be done.

The genesis of the "Stovebolt" Six story goes all the way back to the creation of General Motors by a former cigar salesman named William C. "Billy" Durant. Now some would call Durant a man of vision; others would call him a huckster, but there is no doubt that the largest automotive corporation in the world would never have existed without him. With the goal of dominating the fledgling automotive industry dancing in his head, Durant created General Motors by combining Buick, Oldsmobile, and Cadillac, but in a classic case of reach exceeding grasp, he soon lost control of the company to the bankers and financiers who had put dollars behind his dreams. By the end of 1910 Durant was "out" at General Motors, but the auto industry was clearly not out of his blood, so, instead of fading away like the old soldier, he immediately began to put other automotive deals together, and in that pursuit he got together with a prominent Buick race driver of the era, French-born Louis Chevrolet.

Durant knew that Chevrolet's racing fame -- plus, as W.C. Fields would describe it, his "euphonious appellation" -- had value as a marketing tool, so he persuaded the former mechanic to begin drawing up plans for a new automobile to bear that soon-to-be iconic name. With Louis still at work on the drawing board, the Chevrolet Motor Car Company was incorporated on November 8, 1911. Interestingly, the car that Chevrolet designed was nothing like the car Durant wanted to sell as a Chevrolet. Durant envisioned a small, light, rather inexpensive vehicle, while Chevrolet gave him a big six-cylinder automobile at the Buick level or above, but with Durant pulling the strings, that didn't seem to matter. Within three years of the founding of his company, Louis Chevrolet had left Chevrolet Motor Car Company for good. (Some say that the straw that broke the camel's back was actually a Camel or at least a cigarette. Durant apparently hated the fact that Chevrolet smoked cigarettes instead of the more stately cigars fitting an automotive mogul and told Louis so. Louis reportedly got so incensed he bolted from his company that very day.) In any case, by then Durant had put the Chevrolet nameplate on a car formerly called the Little, which also incensed Chevrolet the man, so it is probable Louis was not long for the company that bore his name in any case. Durant then used Chevrolet to go after Henry Ford and his famous Model T with a Chevrolet model dubbed the 490, which happened to be the widely known price of the Model T.

The success of the 490 and other Chevrolet models like the Baby Grand and the Royal Mail quickly propelled Chevrolet toward the top of the U.S. sales charts where the number one spot was occupied by, of course, Ford Motor Company. It also gave Durant the juice to re-insinuate himself into General Motors Corporation with the help of Pierre S. du Pont. So Chevrolet became part of GM, and Billy Durant was once again at the head of the corporation he founded -- but not for long. Still acquisition-crazy, Durant and GM were woefully over-extended when the recession of 1920 hit. Again the bankers closed in on Durant, and quickly they booted him out of control. Soon thereafter, a group of "business consultants" -- yes, they were wreaking their magic even then -- advised du Pont and his new right-hand man (and the eventual savior of GM) Alfred P. Sloan to dump the Chevrolet Motor Company altogether. But Sloan saw a bright future for Chevrolet at the bottom of the GM range, so he installed a GM veteran by the name of K.W. Zimmerschied as head of the company.

Now Zimmerschied knew the car business; there was no doubt about that. But soon after his installation as the new head of Chevrolet, the top dogs on the GM board decided the company should introduce a Chevrolet model with an air-cooled engine. Zimmerschied was against the idea, but a recent addition to the GM executive team, William S. Knudsen, tested the prototype air-cooled model and enthusiastically recommended its production. Knudsen had a strong resume, having been a key production exec for Ford Motor Company before he and Henry Ford had a falling out, so the GM board dictated the introduction of the new vehicle. Within days, as Zimmerschied had predicted, the "copper-cooled" Chevrolet turned into disaster, but soon after that Zimmerschied suffered what GM flacks called a "nervous breakdown," and Knudsen was annointed in his place.

While the air-cooled Chevy was a certified disaster, the ascendance of Knudsen was a good thing for Chevrolet. You have certainly heard the phrase, "Know your enemy," and nobody knew Ford Motor Company better than W.S. Knudsen, so he was the perfect guy to make Chevy competitive with Ford. Calling itself "The World's Lowest-Price Quality Automobile," Chevrolet instituted annual model changes, bringing good new features to the line each year while the Model T remained stuck in its familiar rut. Using these tactics, Chevrolet quickly made inroads versus the automotive behemoth -- strong enough inroads that Henry Ford was finally forced to admit that the Model T would not live forever. Ford Motor Company designers set about conceiving a new vehicle that would eventually become the Model A, while the Knudsen-led Chevrolet division of GM continually took shots at the rapidly aging flivver.

As Ford came to a screeching halt in preparation for the introduction of the Model A, Knudsen saw his chance to hit his old boss with a one-two punch. First, he would put on a strong push to send Chevrolet to the top of the sales charts while Ford production was disrupted by the shift from Model T to Model A. Then he would apply the coup de grace in the form of a new six-cylinder engine that would trump the four-cylinder powerplant he knew would be in the Model A.

The plan worked as well, if not better, than expected. Ford Motor Company was totally unused to changing models, so the changeover from Model T to A was a tortuous, lengthy and expensive process. The last of the T's became sales-proof because buyers knew a vastly improved version was coming. Then the start-up of Model A production was fraught with delays, so Chevrolet passed Ford for the number-one spot in sales in 1927. Ford did ring in a publicity windfall with its belated introduction of the Model A on December 2, 1927, but Knudsen was ready to take the blow, hang by the ropes for a moment, and then counterpunch. In fact he got more than he bargained for when Ford couldn't get Model A production sorted out through the early part of 1928, so Chevrolet ended up winning the sales race that year, too.

As 1928 turned to 1929 Knudsen was prepared to take his biggest punch of all -- the introduction of the 1929 "International" series Chevrolet, a car that could be equipped with "a six for the price of a four." The key ingredient was, of course, Knudsen's "cast-iron wonder," the "Stovebolt Six."

In truth, there was nothing very remarkable about the engine, except that it was engineered to be built very economically, but the basic design was so sound that it would continue to power Chevrolets into the mid-1950s. One reason for its longevity was the fact that the engineers who developed it were literally forced to make it an overhead valve-design rather than the seemingly obvious L-(flat)head. L-head designs were much simpler and thus cheaper to manufacture, but Chevrolet had long been known for its "valve-in-head" four-cylinder engines, so Chevrolet marketing execs like Richard Grant insisted that the new design boast overhead valves.

That added complication put even more pressure on the GM engineering staff to take costs out of the new six, and they succeeded admirably. The new engine displaced 194 cubic inches with a 3 5/16th-inch bore and 3 3/4-inch stroke. It produced 46 peak horsepower at 2400 rpm. One highlight of the engine was the 46-pound crankshaft that was statically and dynamically balanced. While that piece was state-of-the-art, cost-cutting was evident elsewhere in elements like "splash" lubrication for the rod bearings and gravity-feed lubrication to the three main bearings. (In contrast, my 1926 Nash Light Six has a seven-main-bearing crank.) These slight technical shortcomings aside, the "Stovebolt Six (so nicknamed for its lengthy 1/4"-20 head bolts that held the thing together) was a revolution in the low-priced class.

The engine was immediately plopped into the 1928 "National" series chassis that had been specially lengthened by four inches just to accommodate the new powerplant that would arrive in 1929. By splitting the development and production changeovers over two years, Knudsen, a manufacturing expert, was able to transition very quickly and effortlessly from the four-cylinder to the six-cylinder car without the massive downtime that had plagued Ford. Despite that, though, Ford was able to regain its sales lead in 1929, largely because it was finally able to service the massive backlog of demand from the previous three years when Ford production was stymied by delays.

Still, the "Stovebolt Six" was an unqualified success. In its first year on the market, Chevrolet sold right about one million cars, and by 1931 Chevrolet had wrested the sales lead from Ford and would hold that lead for most of the next 30 years. And one constant during much of that reign was William S. Knudsen's cast-iron wonder, the "Stovebolt Six."

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