The 1949 Cadillac established the pattern for all the V8s produced by the Motor City for the next five decades.
When the 1949 Cadillac V8 was introduced, it wasn’t the first V8 from the General Motors luxury brand. Actually, Cadillac was a pioneer of the V8 in the U.S. auto industry, first offering one in 1915. Nor was this the first Cadillac with overhead valves, as that distinction goes to the Cadillac V16 in January of 1930. Still, the ’49 V8 was a mold breaker, and not just for Cadillac. This new V8 would set the course for engine design in the Motor City for the next 50 years.
Work had begun on a replacement for Cadillac’s aging L-head V8 before World War II, when it was quickly determined that an overhead-valve layout, with its superior breathing and more efficient combustion chamber, was the path forward. After the war, a team led by Jack Gordon, Ed Cole, and Harry Barr began to develop the OHV V8 in earnest. This new Cadillac engine shared nothing with the old Cadillac V8 that was last revised in 1936, and it featured a number of advances beyond the valve-in-head layout.
At 331 cubic inches, the new Caddy V8 was smaller but roughly comparable in displacement to the L-head at 346 CID, but it featured a larger bore and a much shorter stroke: 3.81 x 3.63 inches vs. 3.50 x 4.50 inches. The shorter stroke greatly reduced piston speed, from 2250 feet per minute to 1815 fpm at 3000 rpm, reducing friction, increasing mechanical efficiency, and extending engine life. Meanwhile, the more compact architecture allowed a lighter and stiffer cylinder block with five main bearings instead of three. Despite its bulkier overhead-valve hardware, at 663 lbs the ’49 V8 was nearly 200 lbs lighter than its flathead forebear, and smaller in exterior dimensions as well.
Another key element of the OHV V8’s compact packaging was the slipper piston, above. Designed by GM consultant and engineer Byron Ellis in 1938, the slipper piston’s scalloped skirts allowed it to “slip” between the crankshaft counterweights, allowing shorter, lighter connecting rods and shorter cylinder decks. Ellis also developed a quiter hydraulic valve lifter for the new V8, based on improvements made on Cadillac-powered tanks and personnel carriers during the war.
One key reason for Cadillac’s adoption of the OHV layout was its smaller and more efficient combustion chamber, which supported higher compresssion ratios for greater power and efficiency. This was partly on the advice of the Ethyl Corporation, which predicted the availability of higher octane fuels in the postwar years, enabling ratios of up to 12:1. But for the ’49 V8’s introduction, Cadillac cautiously selected a CR of 7.5:1, only slightly higher than the ’48 L-head’s 7.25:1. (The CR was eventually raised to 10.5:1 in subsequent years.)
Even with the conservative opening approach, the new engine easily outperformed the previous V8, producing 160 hp at 3,800 rpm and 312 lb-ft of torque at 1,800 rpm. The best the old V8 could do after more than a decade of development was 150 hp at 3,600 rpm and 274 lb-ft at 1,600 rpm.
While it was a little smaller in displacement, the OHV V8 was simply more efficient, producing 142 psi BMEP (brake mean effective pressure) versus 119 psi for the L-head. Fuel economy, a specific goal of the project,was better, too, as brake specific fuel consumption (BSFC) was improved 10 percent. Cadillac sales soared with the exciting new V8, from 53,000 cars in 1948 to more than 92,000 in 1949, and with constant improvements and displacement increases, the division offered the same basic engine through 1962.
Jack Gordon, the head of the program, soon became president and CEO of General Motors. Ed Cole and Harry Barr went on to develop the groundbreaking 1955 Chevrolet V8, while Cole also became a GM president and Barr became vice president of GM Engineering. Their impact on the industry was enormous: In just a few short years, every Detroit carmaker would be required to offer a short-stroke, overhead-valve V8, or it wasn’t really in the game. Like the Dewar Trophy-winning 1906 Cadillac with its precision, interchangeable components or the 1912 Cadillac with its electric self-starter, the 1949 Cadillac V8 became a Standard of the World.
The difference between the new ohv Caddy and Olds V8 and the Ford Flathead V8 was stupendous.
American car consumers had the biggest choice in excellent engineering versus bad engineering in 1949 than at any other time in the 20th century.
The obsolete Ford flathead V8 should never have been installed in any “post war” automobile.
How did the Olds V8 differ?
The Olds V8 shared no components with the Cadillac but they were based on the same engineering. The general manager of Oldsmobile C.L. McCuen was on the GM technical committee and when he learned of the Cadillac V8, he insisted that Olds must have a V8 too, and Cadillac was required to share what it knew.
It was the same and first, thus making this article complete rubbish and nonsense.
I didn’t know Jack Gordon was behind the Cadillac V8. He was the GM president who totally banned racing in 1963.
Newly graduated from high school in June, 1950, I applied for and was hired for a summer job at Cadillac Division on Michigan and Clark in Detroit. My job on the line was installing right hand exhaust manifolds on this engine. A few days later I was shifted to connecting the left hand spark plug wires to the plugs and the primary wire between the coil and distributor. In February, 1952 I was hired as a drafting trainee at Chevrolet Engineering on Milwaukee in Detroit. Then came Korea and a four year USAF hitch. Returning from service in 1956, I went back to work at Chevrolet Engineering, now at the brand new GM Tech Center in Warren. After more training I was promoted to the Engine Design Group at Chevrolet, retiring after 35 years drafting and designing various components for many of Chevrolet’s engines. A great career!
Wartime advances in materials had much to do with these developments. It seems Ford and Chrysler expected better piston rings, bearings, valves etc making their old flatheads work better, last a bit longer and smoke a little less would be enough. Those weren’t enough.
First, I find this whole MCG most interesting. Originally from the Detroit area, I vaguely remember many of the things covered hereabouts; many thanks to McG and Co.
I even worked summers a while at the Ford Rouge Plant, in one of the oldest buildings there, mostly making parts for the then brand new Mustangs. There was also an abandoned line there that had very old engine parts just ‘frozen’, that looked like they were for Model Ts or As, which I found interesting.
Older family members worked in some of the places mentioned, I’m finding out from Ancestry documents like old censuses.
And now for the topic at hand, Cadillac engines. I currently have three Cadillacs, an ’85 Seville Commemorative Edition with the HT-4100 4.1L LT8 engine, my low mileage second one [first was in an ’85 Biarritz that I got ~400K miles from]; an engine much maligned by some. The 4.1 was quite a technological advance too for it’s day.
Recently acquired a gorgeous ’04 DeVille with just 20K miles and the really smooth Northstar 4.6L LD8, again another excellent groundbreaking Cadillac design, despite critics. My third Caddy, an ’89 Brougham D’E has a 307 Olds engine which is bulletproof.
Anyway, just begun to explore this very informative site, thanks again for creating and maintaining it about such a deserving place, the Detroit area.
Thanks for your interest!