The title of greatest usually goes to the mighty aircraft engines of World War II, but our candidate is the humble Willys L-134, better known as the Go-Devil.
Many a story has been written with the title “Greatest Engine of World War II.” The usual honoree is the famous Rolls-Royce/Packard Merlin, or sometimes the Pratt & Whitney Double Wasp. These are worthy engines, no question, but we’d like to offer our own candidate for consideration: the humble Willys Go-Devil engine that powered the Jeep. After all, Supreme Allied Commander Dwight D. Eisenhower cited the Jeep as one of the four most important tools in winning the war, while Chief of Staff George C. Marshall called it “America’s greatest contribution to modern warfare.” So let’s talk about the Go-Devil.
The Go-Devil’s story actually begins years before WWII with the 1926 Whippet Four, produced and marketed by Willys-Overland (above). While it was a bit small at 134.2 cubic-inches, it was a typical L-head inline four of its time with undersquare bore and stroke dimensions of 3.125 by 4.375 inches, a 4.4:1 compression ratio, and an initial output rating of just 30 horsepower.
Sold in four and six-cylinder versions, the popular Whippet briefly returned Willys-Overland to the upper ranks in the U.S. sales charts, but then the company was nearly wiped out by the Great Depression. The automaker barely squeaked by for the next several years producing the Willys 77 and its successors, small economy cars powered by versions of the original Whippet Four and eventually rated at 48 hp.
Following a 1937 reorganization and a new shot at survival, W-O recruited a top industry man to serve as vice-president of engineering: Delmar G. “Barney” Roos. Born in the Bronx in 1888, Roos was a fencing champion and award-winning photographer at Cornell University, where he earned dual degrees in mechanical and electrical engineering. A veteran of Locomobile, Marmon, and Pierce-Arrow, he became chief engineer at Studebaker in 1926 where he spent 11 years, leading a number of important advances. After a brief stint as a consultant to Rootes in Great Britain, he arrived at Willys-Overland.
At the time, W-O’s resources amounted to nearly none. The company had been forced to sell off parts of its Toledo factory for operating funds, and Roos had to battle for every dime. No diplomat, he was up for the fight. There’s a story, sworn to be true, that W-O’s penny-pinching chairman, Ward Canaday, once berated the engineering department for using too much drafting paper, that once a precious company asset landed in the waste basket, it was worthless. Roos then lifted up Canaday and placed him in a waste basket. Reportedly, Canaday took it in good humor. Or at least he didn’t fire him.
With only one engine in the company portfolio, the old Whippet Four, Roos went to work modernizing it. The improvements included insert bearings, a counterweighted crankshaft, lightweight 340-gram aluminum pistons, full-pressure lubrication, a new cam lobe design, a revised valvetrain, and improved breathing. The new/old engine (the 134 CID displacement and undersquare bore/stroke dimensions remained) produced more than 60 hp at 4,400 rpm for 100 hours on the dyno, and just as importantly, it could be produced on W-O’s existing tooling. The updated four, rated at 62 hp, went into production in Willys-Overland passenger cars in 1939 and was named the Go-Devil a year later.
As W-O developed a lightweight reconnaissance vehicle for the U.S. Army in 1940, later to be known as the Jeep, Roos simply dropped the Go-Devil passenger car engine into the prototype with a few minor changes to military specs. Reportedly, the engine was the star feature with the Army brass, and W-O won the contract. When Jeep production was consolidated in 1942, Ford manufactured exact copies of the Go-Devil engine, designated by the military as the L-134, and the two companies produced more than 600,000 Jeeps before the war ended in summer of 1945.
When the first civilian Jeep, the CJ-2A, went on the market in late 1945, it was powered by the very same engine as the military version, and the Go-Devil also powered the 1946 Willys Station Wagon and the 1948 Jeepster. “Brothers under the hood,” read the ads. The Go-Devil was produced by Willys-Overland and its successors, Willys Motors and Kaiser Jeep, in the U.S. through 1965. But starting in 1950, the L-head four was gradually phased out for consumer applications with the introduction of the overhead-valve Hurricane four. But in fact, the Hurricane was an F-head conversion of Barney Roos’ Go-Devil.
Fascinating, Captain, but why was it called “Go Devil”? Because it was likened to the saying “going like the devil”, although, I’m not really sure what that meant either. While the war accolades for the Jeep are many, it had just as much in the private sector. Much to a kids dismay, many a driveway was cleared, thanks to the Jeep 4 cylinder. It was the most common fixture of any service station, a Jeep was the “do all” and most plowed snow for years, and the Go Devil never went to the devil after all. I , due to the respect of the vehicle, and for what it stands for, drive a 1991 Jeep YJ Wrangler, that really is not much more than a glorified army Jeep. It has the anemic 2.5 4 cylinder, and while not much of a road vehicle, it still embodies a lot of what the original had, and I’m proud to drive a Jeep.
“Goes like the devil” was a more popular expression than it is today. It was a euphemism, the polite way of saying “goes like hell.” Most of the dealerships I worked at used Jeeps to push snow on their lots. At one, the Jeep’s clutch had to be replaced after every snowfall. If you saw how the lot guys used it, you would know why.
Hi Howard, greetings from Albuquerque! I like the much to kids dismay, the Jeeps plowed many driveways. Thankfully not many in my neighborhood could afford or wanted someone to plow. We kids would band together and go door to door asking folks to shovel their driveway for a dollar each. The only exception was the elderly lady whose driveway we cleared for free. I remember complaing about the huge double driveway that seemed like it took forever to complete. Later after we moved and I was just out of high school more folks were having their driveways plowed by the little Jeep and them came the pick up trucks.
Hi BigRed, by gar, it’s been a while. I’m still in Colorado, and getting older thankfully. Great to hear from you. In the 60s in Milwaukee, ( and Chicago) we had some mombo snowstorms, or seemed that way to a kid. We had to walk uphill both ways in blizzards to get to school( cough). I think it was like $5 bucks to plow a drive then and I remember the sound they made just before dawn, indicating I better get that book report done that I put off.
Many sources attribute the Jeep design to American Bantam, with both Willys and Ford brought in as AB was too small to meet demand. Did they also win the initial contract with the Go-Devil engine?
Who designed the Jeep is a complicated and controversial subject. Karl Probst for Bantam is generally named in the common narrative, but he never made that claim and that narrative arose after he died. Others at Bantam may have been as much or more responsible than Probst, it would seem. Both Ford and Willys were awarded contracts, but the program was later consolidated on the Willys vehicle. There’s an entire rabbit hole to explore, but my personal view is that as much as anyone, the U.S. Army designed the Jeep with its bid specification.