The Engine Detroit Banned Before Anyone Knew Its Name
February 1955, in Daytona Beach, a driver named Tim Flock is behind the wheel of a Chrysler C300 hammering down the shoreline at 127.5 mph, leaving everybody else in the dust.
There was nothing special about that car from the outside, but under the hood was a V8 engine that Chrysler called the Firepower.
And that year, it won 27 out of 38 NASCAR races, running straight from the production line to the track without a single modification.
This is the story of the first Hemi.
Not the 426 you already know, something that came 13 years before it.
Born from a secret weapons program in World War II that the world has almost completely forgotten.
To understand why the Firepower hit the industry like a shockwave, you need to know where Chrysler actually stood in the late 1940s.
Detroit was moving fast.
In 1949, Cadillac and Oldsmobile both launched new overhead valve V8s.
Cadillac used their new 331 CI V8 to win the very first Motor Trend Car of the Year, putting out 160 horsepower, a number every other manufacturer was scrambling to match.
Oldsmobile did something even bolder.
They dropped the Rocket 58 into a smaller body, created the Rocket 88, and took it straight to NASCAR.
The result, six wins out of nine Grand National races in year one.
No special preparation.
The car went from the dealership to the winner’s circle.
And Chrysler?
In 1950, Chrysler was still selling cars with a flathead straight eight.
Not because they didn’t know better.
The straight eight was actually a reasonably dependable engine.
It had overhead valves, and technically it wasn’t that far behind.
But it was heavy, it was bulky, and it clearly had no future in an industry that was running away from it.
Chrysler knew they needed a V8.
The question was, what kind?
And, here’s the interesting part.
They weren’t just trying to build a V8 to keep pace with Cadillac.
Chrysler wanted something technically different, something the competition didn’t have.
While GM was finishing up their overhead valve V8s, a group of Chrysler engineers was going through files from a canceled military program.
One the US government had handed them during World War II, one that had never been made public.
The program failed because the war ended too soon.
The airplane it was designed to power never flew into combat, but 5 years of research on a very specific type of combustion chamber didn’t just disappear.
It sat in the heads of those engineers waiting for something worth using it on.
Chrysler decided to use it to build a V8 that Detroit had never seen.
That V8 had a name, the 14 2220.
And, it was never meant to go anywhere near a road.
In 1940, the US Army Air Corps came to Chrysler with a serious request, design and build a 2,500 horsepower aircraft engine for the heavy fighter P-47 Thunderbolt.
Chrysler took the job and went to work on something nobody had attempted at that scale before.
They called it the 14 2220, a massive V16 displacing 2,220 cubic inches, or 36.4 L.
Nearly six times the displacement of a modern V8.
Essentially, two V8s bolted back-to-back sharing a single central drive shaft.
Over 10 ft long, weighing more than 2,300 lb.
To squeeze 2,500 horsepower out of an airframe, every combustion event had to be as efficient as possible.
That’s when Chrysler turned to the hemispherical combustion chamber.
The basic concept goes like this.
Instead of burning fuel inside a flat boxy chamber like most engines of that era, you shape the chamber into a dome.
The spark plug sits dead center and the flame front spreads outward evenly in all directions without getting trapped in corners or flat walls.
More importantly, the dome shape allows you to place two large valves on opposite sides of the chamber, one intake, one exhaust, instead of cramming them side by side in a tight space.
More air in, exhaust out faster, and the result is more power from the same amount of fuel.
The trade-off was that this design was complex, heavy, and far more expensive to produce than a conventional engine.
Chrysler built it anyway.
It took 5 years.
Single-cylinder test started in May 1941.
The complete engine ran for the first time in late 1942.
The first test flight happened in July 1945 on a P-47D.
And 4 months later, in November 1945, a propeller shaft snapped during testing.
The program was canceled that same day.
The war had already ended in AuguSt.
The XIV-2220 never went to war.
For most companies, that’s a failure you bury as quickly as possible.
But Chrysler kept all of it.
Every piece of knowledge about hemispherical combustion chambers went straight into the automotive lab, and the engineers began scaling the concept down to the size of a passenger car V8.
They also partnered with Continental to develop a hemispherical V12 for the M47 Patton tank, giving them a few more years of field experience to understand what worked and what didn’t.
By 1950, Chrysler was the only company in Detroit that fully understood hemispherical combustion chamber design from the inside out after an entire decade of working with it in a military context.
In February 1951, they put it in a family car.
That same year, a writer named Tom McCahill drove the new Chrysler New Yorker to Daytona Beach and won the trophy for the fastest American stock car, but that was just the opening act.
In 1952, Chrysler bolted a fuel-injected FirePower into a Curtis-Craft 500A roadster and brought it to Indianapolis Motor Speedway for testing.
The engine ran 1,500 continuous mi, including a simulated 500 mi race, and came in 4 mph faster than the existing track record.
Not a purpose-built race car, a production engine dropped into a test chassis.
The Indianapolis officials noticed, and they were not happy about it.
In 1954, Indianapolis rewrote the rules, dropping the displacement limit to 272 cubic inches.
The FirePower was locked out completely.
Not because it had broken any existing regulation, but simply because they wrote a new one to keep it out.
Done.
Problem solved.
But, Indy was just one track, and the FirePower’s real story started 3 years before any of that.
On the 9th of February, 1951, Chrysler launched the FirePower.
Not as a premium option or a performance package.
The FirePower 331 CI was the standard engine on the New Yorker and Saratoga.
You bought the car, you got the engine.
The specs: 330 1 cubic inches, 7.5 to 1 compression, 1.81 in intake valves, 1.50 in exhaust valves, spark plugs centered in the combustion chamber, 180 hp at 4,000 revolutions per minutes.
180 hp sounds modest today, but in 1951, that was the highest number any American automaker had in production.
Cadillac’s best overhead valve V8, also a 331.ci, was rated at 160 hp.
The FirePower didn’t just beat its closest rival, it beat the entire American auto industry in its very first year.
Chrysler also didn’t keep the technology to a single model line.
DeSoto launched the FireDome 276.si in 1952.
Dodge followed with the Red Ram Hemi 241.si in 1953.
Within 2 years, the hemispherical combustion chamber had spread across the entire Chrysler Corporation lineup.
By late 1953, Chrysler had already upgraded the cylinder heads for the 1954 model year, intake valves up to 1.94 in, exhaust up to 1.75 in, with the four-barrel version hitting 235 hp.
The hot rod community started paying attention.
Briggs Cunningham fitted a FirePower into his Cunningham C-5R and took it to Le Mans in 1953, finishing first in class and third overall.
Drag strips started seeing more and more Chryslers.
The airflow advantages of the hemispherical design meant you could raise compression and swap carburetors without touching most of the engine’s fundamental architecture, and a completely stock FirePower was already quicker than a heavily modified Ford flathead V8.
Indianapolis shut the door on the FirePower in 1954.
NASCAR hadn’t, and in 1955, a man named Carl Kiekhaefer, an outboard boat motor manufacturer who had never been involved in car racing, bought a team of Chrysler C-300s and entered NASCAR.
That year, Kiekhaefer’s team won 27 out of 38 NASCAR races.
A fleet of Chrysler C-300s with FirePower 331.ci under the hood, 300 hp, the The powerful production car in America at that moment, Tim Flock drove the C300 to a two-way average of 127.58 mph at Daytona Speed Weeks.
He Kay Fer took the NASCAR Grand National Championship that year.
Then he took it again in 1956, this time with the C300B.
Firepower now at 354 CI, 355 HP, 10:1 compression ratio.
Buck Baker won 14 races.
A stock C300B set the world passenger car land speed record at Daytona 133.9 mph.
Also in 1956, a drag racer named Don Garlits, who would later be known as Big Daddy, started running Chrysler Hemis on the drag strip.
He would keep at it for the next 46 years.
By 1958, the Firepower hit its peak with the 392 CI.
The carburetor version produced 380 HP.
Chrysler also tested the Bendix Electrojector electronic fuel injection system rated at 390 HP.
Garlits broke the 170 mph barrier in his Hemi-powered Swamp Rat dragster.
The Chrysler 300D set a class E land speed record at Bonneville 156.387 mph.
Then Chrysler recalled nearly every car fitted with the Bendix Electrojector because the system was too unreliable to keep in service.
And that same year turned out to be the last year of the Firepower, killed at its absolute peak, replaced by a cheaper and simpler wedge head B engine.
The real irony, Bosch bought the Bendix Electrojector patent and used it as the foundation for the fuel injection systems that dominated the global auto industry through the 1970s and 1980s.
Technology Chrysler developed for the the abandoned by Chrysler, ended up powering an entire industry, just under someone else’s name.
And that’s exactly what Chrysler did with the Firepower itself.
Walked away from it, not because it couldn’t compete on performance, but because it was too expensive, too heavy, and too complicated to survive in a mass market business.
It weighed close to 1,000 lb, significantly more than where Detroit was heading.
The hemispherical combustion chamber with its two separate rocker shafts cost more than twice as much to produce as a conventional wedge head.
And Chrysler dealerships across the country simply didn’t have enough technicians who understood it well enough to keep it running properly.
Customers bought the car and couldn’t find anyone to fix it.
Those three problems together were enough to convince Chrysler’s leadership that the wedge head B engine was the future.
Powerful enough, easier to build, easier to service, more practical.
Drag racers didn’t care about practical.
They were still running 392 Firepowers competitively on the strip well into the 1970s.
Today, a clean original 392 is something collectors chase hard.
They’re not easy to find and they don’t come cheap.
In 1964, Chrysler came back with the elephant 426 cubic inches, which dominated the Daytona 500 inches its very first year of competition.
NASCAR panicked and told Chrysler they had to sell a street legal version before they’d be allowed to keep racing it.
Chrysler agreed, and for the first time ever, they officially called it the Hemi, trademarked, printed on the cars, printed in the ads.
The funny thing is that Hemi isn’t technically accurate.
The Firepower’s combustion chamber wasn’t a perfect hemisphere.
It was a spherical cap, a dome that’s shallower than a true half sphere.
Chrysler’s engineers went with Hemi because it sounded a lot better than spherical cap.
They called it Firepower for eight straight years and never once used the word Hemi.
That name only appeared after the engine was already dead and it was given to a completely different engine.
Firepower is the most important engine that most car enthusiasts have never really looked into.
I genuinely believe that.
If Chrysler hadn’t pulled that knowledge out of a failed wartime program, the horsepower wars of the 1950s might have gotten started a lot later and the name Hemi that people still throw around today might never have existed at all.
