The Original Chrysler Hemi EngineCopyright © 2004 by Curtis Redgap, Orlando, Florida. All rights reserved. Contact Allpar for reprint permission. Based on a large variety of sources.

HEMI! The First.

The King did not die!

Long Live the KING!

The decision made by Chrysler Corporation in the late 1940s concerning building a V-8 engine lead to one of the most technologically advanced automotive engine designs in the world. With it, new ground in terms of performance, was created, in that it lead the way for making power.

How the engine got produced is an intriguing story. That it did get the go-ahead from a very staunch group of ultra conservative engineers is a testament to the basic design itself.

It has been well documented that with the release of the first generation of Hemi headed V-8 engines, Chrysler set off the "horsepower wars" of the early 1950s that lasted into the early 1970s. Certainly, it forced General Motors and Ford Motor Company to keep upping the ante in making more power from their engines.

If you look at applications running today, you have to go no further than the major drag racing organizations. The top engines for producing huge amounts of horsepower, along with one that continues to set speed records, are those with hemispherical heads on them. The early Hemi lead Chrysler to develop the second generation of the Hemi headed V-8. And as this is written, a third generation is proving its worth in current Chrysler vehicles.

Chrysler Corporation began testing different engine designs prior to the beginning of World War II. Pinpointing an exact date is just not possible since the records in that era were spotty, misplaced, or not recorded at all. From all indications the work of making new engines got started in 1937. This work continued during the war, and of course, went right on, after the war was concluded. Nothing was left to conjecture, however, with every imaginable type of engine receiving scrutiny by Chrysler Engineering. This included but was not limited to a 5 cylinder in line, several 6 cylinder inlines, 60 degree V-6s, 90 degree V-6s, and of course several 90 degree V-8s. All sorts of different exhaust and intake combinations were tried. The 90 degree V-6 was found to be very unsatisfactory because it lacked smoothness. The weight and length of a straight 8 engine was now considered as too heavy and too long. Two stroke cycle engines were rejected because they were noisy and smoky.

The advent of World War II did not stop the engineering department from working on new engines. Out of need, these men developed a superb tank engine by combining five inline flathead Plymouth 6 cylinder engines in a radial combination that worked on a single common crankshaft. It was rugged, durable, powerful, and fairly economical as well. It went on to power hundreds of tanks that were also being built at the Chrysler Corporation. One of those engines is on display in the Walter P. Chrysler Museum in Auburn Hills, Michigan.

Along the way, the engineering staff, lead by Supervising Engineer John Platner, had began to use a single cylinder engine to test new head designs or combustion chambers. Their concern at that time was the loss of volumetric and thermal efficiency due to carbon deposits. Some losses would occur with as little as 10,000 miles on an engine. Once these deposits got started, they would just increase until engine power would be down as much as 20% - a truly noticeable difference.

One area that had shown really true promise was the hemispherical combustion chamber. The standard wisdom about such a "Hemi" was that the engine was rough and liked high octane fuel. As well, the cost and complexity in manufacturing such an engine could not be justified in a mass production environment. Yet, testing results indicated that just the opposite seemed to be true concerning the Hemi.

Chrysler had begun development of two large hemispherical headed engines during World War II. One was a V-12 for application in tanks and the other was a V-16 operating in a inverted position for the aircraft industry. Neither of these engines ever reached production - not because they weren't good, but because there was just so many other things going on, and winning the war was job number 1.

The first Chrysler Hemi - an airplane engineWhat did come from testing the aircraft engine was just another Chrysler accomplishment that went by unheralded but was nevertheless noted later. The inverted V-16 was conservatively rated at 2,500 horsepower, and Chrysler has always been known for under rating their engines.

For testing, a P-47 Thunderbolt was selected. Introduced in 1943, the P-47 was the largest and heaviest single seater in the Air Force inventory at the time. It was powered by a huge 2,800 cubic inch radial engine that developed 2,300 horsepower. It gave the 40 foot wing span plane a top speed of 439 miles an hour at 15,000 feet.

Some modifications were necessary to accommodate the long V-16. When done, the slimmed down nose actually helped reduce the drag produced by the big round radial. Preliminary testing showed promise. Gingerly the big fighter was coaxed slowly into higher altitudes and higher speeds. Finally the go ahead was given for an all out test. At 15,000 feet, the huge plane, under the Chrysler V-16's power, broke the 500 mile an hour barrier. No one thought it was possible for a piston engine to achieve that speed in level flight.

Thanks to accurate radar timing, it is beyond doubt how powerful that engine truly was. Flat out, it pulled the huge P-47 along at 504 miles an hour. Conventional wisdom at that time said that the V-16 was making at least 3,000 horsepower, and likely closer to 3,500!

Just to be sure, the test P-47 went out the next day with a different test pilot and again level at 15,000 feet, went through the 500 mile an hour mark. Hand shakes and elation went all around. However, only the one engine was ever built. The important thing to keep in mind about this engine is that it was a Hemi headed, push rod valve activated type. It survived the war, and now is on display at the Walter P. Chrysler Museum in Auburn Hills, Michigan. Note: Bob Nist saw a Chrysler add in Space Smithsonian which claims three were made - one being at the Smithsonian.

Editor's note: This site shows a Continental "Hyper" inverted-V12 engine which features "spherical" combustion chambers and sodium cooled exhaust valves. This engine produced 1,600 hp. in 1943, and was tested in the Lockheed XP-49 and McDonnell XP-67. Like the Chrysler V16, it was never made in mass production.

Hemispherical heads in cars: the state of the artAt the end of the war, of course, engineering now knew how good the Hemi heads could be. Not that they were something new or invented by Chrysler. The first recorded use of a Hemispherical combustion chamber was a four cylinder affair that powered a car named the "Welch." There seems to be a conflict as the origin of the Welch. One records it as being a Michigan company, while another excellent source said that it was a British design. Chrysler was also not the first company to test or use the Hemi heads on an engine. It was the design of choice for many famous marques in the automotive industry. Miller racing. Duesenberg. Stutz. Offenhauser. All high performance machinery.

There is an urban legend about the legendary General Motors engineer Zora Duntov, better known as the father of the Chevrolet Corvette. Before coming to GM, he designed a set of Hemi heads that were retrofitted to the Ford flathead V-8. Legend has it that Chrysler somehow "borrowed" the design from Duntov. Nothing could be further from the truth. Duntov didn't know anything about what Chrysler was doing, and Chrysler had entered into Hemi engineering long before Duntov began construction of his aftermarket, bolt on heads. If anyone at Chrysler was aware of the Duntov innovation, it was certainly never acknowledged.

A Duntov headed Ford V-8 is on display at the Don Garlits Speed Museum in Ocala, Florida. At first glance, it certainly appears to resemble the Fire Power. That would only reinforce the fact that great minds travel in the same circles.

Walter P. Chrysler was always proud of the "boys" in engineering, but he could still disparage them with the best of his well-known temper. The Airflow may have been meant for DeSoto only, but Walter wanted it yesterday for Chrysler. The engineering staff advised it was being rushed and that manufacturing wasn't up to making sure that the line techniques were going to ensure a quality car, but Walter kept up the pressure. That gave General Motors, which was running scared of the design, time to spread vicious rumors about it.

Engineering held sway at Chrysler at the time. Walter P. Chrysler had gotten his start with a car that was designed and built by three engineers who had been working for Studebaker. Fred Zeder, O. R. Skelton, and Carl Breer made it possible for Walter Chrysler to be able to introduce the first true high compression in line 6 cylinder flathead engine in his 1924 Chrysler car. They also saw to it that the Chrysler had the new Lockheed hydraulic brakes on all four wheels. Breer was credited or panned, whichever way you choose to look at it, with the styling and engineering development of the 1934 Airflow Chrysler. That model has now been credited with being the first car of its time from which all modern designs are now based. Had it not been rushed, it would have been a great success.

Working in the engine development area was James Zeder, the younger brother of Fred. Working for James were Ray White, Mel Carpentier, and William Drinkard. Joining this group was a young Ev Moeller, one of the first graduates of the Chrysler Institute in 1939. He came aboard the automobile engine development team in 1947 after working through the war in the aircraft engine development program. These men tested virtually every engine they could find in every combination that they could think of.

One of the engines they tested that truly stood out for power and efficiency was built in England by Healey. It was used in a small passenger car. It had twin camshafts, located in the block. They operated push rods for the overhead valves in the hemispherical combustion chambers. It was a long stoke, small bore engine, yet it made the most power for its size of any engine they had tested to date.

John Platner testing the different configurations on the single cylinder engine in the lab, found the Hemi head was displaying characteristics opposite of what the established doctrine indicated. The Hemi limited knocking. It also had far superior volumetric and thermal efficiency. With a compression ratio of 7.0 : 1, the Hemi beat the L-head which required a compression ratio of 10.0 : 1 to achieve the same results. The overhead valve arrangement was somewhat better than that, but suffered from losses in volumetric efficiency, and the valves did not last.

It was clear that the Hemispherical combustion chambered heads were superior to all else. The intake valve was situated close to the manifold and carburetor. At an angle of 58 degrees across the top of the combustion chamber, the exhaust valve allowed magnificently efficient burnt gas releases. Because of this, the heads extended valve life, aiding in effective uniform valve stem cooling and valve seat cooling inside the chamber. With that information in hand, James Zeder elected to go ahead and test the head on one of Chrysler's existing engines.

A double overhead camshaft arrangement driven by a dual chain had to be made to accommodate the Hemi shaped combustion chamber. Once that was done, and suitable modifications made to the Chrysler 6 cylinder engine, it was installed in a Chrysler car. The test vehicle went to Wallace Zierer, who was in charge of getting results in actual road test conditions.

Mr. Zierer reported significant power increases. The engine ran easily on the 80 octane fuel that was standard for the time. Roughness, which was the current theory about hemispherical heads, just did not exist under any condition. The Hemi head 6 cylinder engine actually being smoother than the flathead 6 cylinder, with a nearly undetectable level of noise and vibration at idle speeds.

Chrysler Corporation background: complacencyThe Airflow was mentioned earlier in this article for a reason. It had been a commercial sales flop. It nearly sent DeSoto, with only an Airflow design as a single body style in the introduction year of 1934, into insolvency! The Chrysler line had a companion make called the CA Six ("Airstream"), which was conventionally styled. That kept the wolf from Chrysler's door in 1934.

Walter Chrysler stepped down from his own company the very next year. He complained mightily about his own engineering staff. Some speculate he was displeased with their caution in getting the Airflow to market (see earlier sidebar). A whole chapter could be devoted to this and I will not go there in this, except to set the background for the mood in Chrysler that prevailed after the failure of the Airflow. The Corporation stopped innovating, and if you are not constantly evolving, the business is standing still.

After allowing the Airflow to die a slow death when the 1937 model year was over, Chrysler Corporation did not reach out to any innovative style or even new engineering for a listless period of nearly two decades.

A prime example concerning the lack of engineering innovations was in the area of transmissions. General Motors used Oldsmobile as its experimental or introductory division for new engineering. In 1937, as the Airflow was being left to wither, Oldsmobile introduced a 4 speed semi-automatic transmission that required very little use of the conventional clutch. It had two ranges, a low and a high. Within those two ranges were two speeds for each range. Using the clutch, the driver would select either of the two ranges. With the range selected, he could then let the clutch out and move off. The transmission would then hold in either Low First, or when the driver lifted his foot from the accelerator, the transmission would audibly "clunk" into Low Second. The driver could then drive all day if he choose to remain in low ranges without ever having to clutch again, unless he choose to select high or reverse. In normal use, high range would be selected. The car would start out in High Third. At around 11 miles an hour, the driver lifted his foot from the accelerator, and the transmission would "clunk" into High Fourth, where conventional highway speeds were obtained. If the driver never had to back up, he did not have to use the clutch pedal again, even in city stop and go driving. Acceleration was leisurely, but it certainly made for a lot of publicity. After all, it was the first real attempt at innovation in transmissions. It was fairly simple in that it used a fluid torque converter that drove two planetary units (shades of Henry Ford's Model T transmission) with one brake and one clutch band each. Shift points were pre set according to oil pressure. A limited extra cost option for Oldsmobile in 1937, it was offered across the board in 1938. 28,000 installations were recorded. The industry was put on notice with that.

Chrysler's first "torque converter" was technically a fluid coupling, which converted torque into forward motion without a clutch. Buick tried a five speed fluid drive which became a maintenance nightmare, and switched to three speed sticks until 1948 - not using the Olds transmission.

Chrysler had to take notice of Oldsmobile's semi-automatic. Their answer was technologically innovative, however, rather tepid in response. Rather than go through building up a semi-automatic, Chrysler installed a torque converter ahead of a conventional clutch, which drove a regular three speed transmission. It had the similar effect of clutchless driving in that the car could be left in third gear (or whatever gear was selected) all the time. You only had to use the clutch when shifting gears. Moving off was very leisurely, but it worked, and kept costs of development low.

It took Chrysler two years to get that far. So when the "Fluid Driving" experience was introduced in 1939, besides being limited to the top of the line Chrysler cars only, Oldsmobile had shot by Chrysler big time with its derivative of the semi-automatic that had evolved into the first fully clutchless truly automatic transmission, the Hydra-Matic. People couldn't get enough of them. It was a $57 option. Although it operated through a complex set of gears, clutches and brake bands, it was solid, rugged and very reliable. It was offered in Oldsmobile in all 1939 models. The very next year, Cadillac, and Pontiac had the Hydra-matic available in all their car lines. As well, it was being purchased for installation in Nash, Hudson, Kaiser and Frazier automobiles. Chrysler engineering seemed like it was mired in mud. It did very little in response.

Finally, in 1941, Chrysler introduced fluid drive to the DeSoto and Dodge lines. (No explanation for not giving it to Plymouth, their largest producer.) They answered the Hydra-Matic with a new semi-automatic available for its own marque. In operation, it resembled the 1937 Oldsmobile's semi-automatic, while mechanically it was less complex, and used engine vacuum to operate the bands in Low or High ranges for the four speeds. Dubbed "Vacu-matic," it was less than could have been expected for such a great team of engineers. After all, at that point, engineering was running the Chrysler Corporation!

That was the mood in and around Chrysler Corporation as it entered the war years. It was like a period of hibernation. Unfortunately, the decision or lack of decisions was being reinforced with the decline of the Ford Motor Company because it pushed Chrysler Corporation into being the number two vehicle producer. This status lasted past the end of the war, with Chrysler remaining number two in vehicle production in 1947 and 1948. The corporate heads were not paying attention much to what was happening at General Motors or Ford. Given the satisfactory high sales figures in the warmed over 1941 style 1947 and '48 cars, they choose to ignore the styling changes and engineering innovations coming from the other car companies. It would hurt them in the very near future.

The production version of the Chrysler Hemi V8 gets approved, with tough standardsEnter this climate then, came the younger brother of Fred Zeder, James, leading an innovative, aggressive group of engineers, who wanted to build a Hemi headed, compact block, 90 degree V-8 to power Chrysler cars.

In any corporation, there are wide differences of opinion. Care has to be taken whenever you try to advance your idea because other guys who want to advance their ideas act against you. So it went with James Zeder when he made his presentation for the new V-8. His own brother, Fred Zeder, told the group that Chrysler had made its money on straight engines. He (Fred) would have no part of a V-8 and never would. I can't imagine how James must have felt with that from his own brother.

William Drinkard had become Manager of the Engine Development Department in 1943. He and John Platner refused to give up on the concept of a compact Hemi headed V-8. It was well known that Cadillac and Oldsmobile were working diligently on their own compact V-8 engines slated for introduction in model year 1949. Taking the concept to the board room resulted in some heavy arguments. A large group of research experts were brought in and total confusion reined. Finally, the Chief Operating Officer stepped in.

K. T. Keller had been personally selected by Walter Chrysler to succeed him as Chrysler President. Normally known as very conservative, K. T. said to Drinkard; "Bill, I think you have the right plan". That settled the issue and turned everything around. Within a few weeks, in 1948, the engineers had a 330 cubic inch 90 V-8 with Hemi heads running in the laboratory. Designated the A182, this engine was exclusively used on a dynamometer to evaluate its performance and characteristics. After many tests, Chrysler management was suitably impressed. They gave the O. K. for an engine of this size and type to be designed for production. The Hemi was to be!

With the order in hand, Mel Carpentier's department built the prototype Hemi V-8. Designated model A239, it had a slightly higher displacement at 331 cubic inches, and was shorter and lighter than the A182. Of course, it was built with manufacturing considerations foremost in mind. It was also built to specifications laid down by William Drinkard, head of engine development. He set down some very tough parameters for them to follow. He wanted a 100,000 mile engine and would accept nothing less. It was a major effort to achieve those standards. Drinkard was resolved. No major parts to be replaced, such as bearings, valves, pistons, and rings, at anything less than 100,000 miles.

A major obstacle right off was premature camshaft wear. It was Chrysler's first attempt at a production overhead valve engine. They were not familiar with valve loading, which caused the area between the valve tappets and the camshaft lobe to wear very quickly. Some of the prototype engines failed right in the engine plant. Clearly they wouldn't have gone a 100 miles, let alone 100,000.

Bob Rodger (later to be head of development of the 300) was called in with a team to assist in solving the wear problem. With a lot of trial and error, eventually the highly skilled engineers did resolve the camshaft wear issue. It took a change in the tappet material and the method in which the face of the tappet was formed to reduce the valve unit load. A graphite coating and an additive in the engine oil settled the whole issue.

Another major hurdle was how to enable spark plug changes without taking off the large valve covers. This was finally resolved by using a steel tube that went through the valve cover, a long ceramic boot over the spark plug, and an o-ring to seal the tube against the head to prevent oil leaks. The spark plug tubes and wires were put underneath a cover that had the wires exiting at the back of the engine which gave the new V-8 a clean look.

Other engine improvements included shot peening of the crankshaft to improve fatigue life and having it machined to remove any tool marks or surface roughness. The tappets were hydraulic to enhance quiet, smooth operation, as well as to ensure valve life through constant control of opening and closing. Chrysler worked with the Carter Company to develop a water jacketed carburetor with an integral automatic choke to insure that the new engine would not stall nor develop ice within the carb. A dual breaker ignition was developed to insure constant, hot sparking while maintaining a reserve of ignition voltage.

Finally, after over 8,000 hours of rigorous dynamometer testing, and more than 500,000 miles of road testing for reliability, the Chrysler V-8 was ready for production. Based upon the data submitted from all the tests, the engine was given its final "go". It was finally ready.

Along the way, the new engine had been designated "Fire Power." So certain were the management team of the success of this engine that some months into the testing of the Fire Power, orders had been sent out to DeSoto and to Dodge to submit proposals for a Hemi V-8 of their own. Plymouth seemed to have been left out, a portent for the future.

Introduced in the fall of 1950 as a 1951 model, the Fire Power V-8 was offered as on option in the Saratoga (except for the coupe models), while it was standard in the New Yorker and Imperial. The lesser Windsor models made do with the flat head six of 250 cubic inches.

The Fire Power was an oversquare engine in that the bore was larger than the stroke. As built it had a bore of 3.81 inches and a stroke of 3.63 inches, that measured out to 331.1 cubic inches. The intake valve was 1.81 inches. Positioned 58.5 degrees across the hemisphere was the exhaust valve that was 1.5 inches in diameter. The valves were actuated by push rods operating rocker arms. The rockers rode on twin shafts. It was well damped, and the crankshaft rode on 5 main bearings.

Chrysler designed the pistons to be able to "slip" between the crankshaft counterweights at the bottom of the stroke, thereby achieving a much smoother running engine, with less friction and slower wear characteristics. The engineers also built the Fire Power to run with slower piston speeds which ensured long piston and ring life.

The block was relatively light, short and very rigid. With a two barreled carb it made 180 horsepower (gross) and 312 foot pounds of torque. The introductory compression ratio was 7.0 : 1. Some criticism was leveled at the weight of the engine, in particular the weight of the Hemi heads. In fact, a single Hemi head, fully assembled, weighed 119 pounds. The Cadillac engine head weighed 93 pounds each. I wouldn't have wanted either one to fall on my toes. Overall, critical comments had less sting because both engines weighed in at 700 pounds. The Hemi beat out Cadillac's V-8 by 20 horsepower while using less squeeze than that Cadillac's 7.5 : 1 ratio. The Cadillac and Fire Power V-8s measured out 331 cubic inches. Whether making the engine the same size was deliberately done on Chrysler's part is just conjecture - right?

From the very start, performance was on everyone's mind. Someone convinced Chrysler management to install the Fire Power into a Saratoga Club Coupe. It was the lightest body manufactured by Chrysler at the time. Released in July of 1951, the Fire Power Saratoga Coupe was a first shot response to Oldsmobile doing the same thing in 1950 when they installed their V-8 in an 88 Coupe. The Saratoga was a real fire cracker right off the production line. It would sprint the car from rest to 60 miles an hour in 12 seconds flat! It beat Cadillac's 13.5 second run, and Olds' 12.5 second time. It ran the 1/4 mile in 18 seconds at around 82 miles an hour, about as fast as any stock car off the show room floor that was around. The Chrysler New Yorker Convertible was chosen as the pace car for the Indianapolis 500 race.

FIRST RACE WON WITH A HEMI

Using a new Chrysler Club Coupe on a New Yorker chassis, Tommy Thompson drove the Hemi to its first win at the Detroit Fair Grounds in front of Ford and GM executives. It was a half mile dirt track of 250 mile duration.

The Fire Power had ample reserves of untapped horsepower, which the engineering staff was very well aware of. For the time being, Chrysler was interested in further development and improvement of the Hemi, but not high performance. At least, not at first.

In March of 1952, James Zeder (now Vice President of Engineering) and some of his team presented a "white paper" to the Society of Automotive Engineers. Right after the meeting he was mobbed by what he called the "hot rod" boys. They were over enthusiastic, boisterous, even obnoxious. But as Zeder was fond of recalling, "they were so darn involved with maximum horsepower out of our Fire Power, I just couldn't help being intrigued with what they had in mind as well as listening to their suggestions." With that, performance testing was commenced in the Chrysler engine labs on the Fire Power. While the testing progressed, Mr. Zeder kept in touch with his adopted gang of "hot rod" boys. He listened to and passed along their suggestions on how to make the Hemi "grow."

The first investigation involved two areas for increased performance: compression ratio and volumetric efficiency. Using high compression pistons, compression ratios of 7.5 : 1, 10.0 : 1, and 12.5 : 1 were tried. Nothing else on the engine was changed. The 12.5 : 1 pistons achieved a 15 % increase in horsepower over the 10% increase with the 7.5 : 1 pistons. That translated into about 228 horsepower. But, it would run only on aviation gasoline of 130 octane. That high CR would have to wait for general use fuels to be widely available across the country.

The next area involved volumetric efficiency. The stock exhaust headers were replaced for streamlined units. That alone increased torque from 312 foot pounds to 330. The horsepower went up to 193. Gaining confidence, they explored other areas for improving volumetric efficiency: the valve ports, intake manifolding, carburetors, and camshafts.

The Hemi heads had plenty of room for much larger valves. Moving slowly, the ports were smoothed, and then opened up .125 of an inch on the exhaust and .25 of an inch on the intake. For manifolding and carburetion, engineers developed a set of 4 inline, single barrel carbs, each feeding two cylinders. They also experimented with different grinds on the camshaft. As it happened, the electronic computer was newly introduced, and Chrysler Corporation, no stranger to electronics by any means, was one of the first companies to utilize computer generated computations to achieve the maximum out of the camshafts it was testing.

H. David Braew wrote: Many years ago I worked for the Getty Oil Company. In those days Getty had its own well servicing equipment (today you hire specialist contracting firms - for more money and less productivity). The best service unit was powered by an industrial 392 Hemi. That thing was known for its ability to pull the pipe out of wells faster and easier than any of the other service equipment, powered by Hall-Scott, Detroit or Cummins engines of the day (in the 1950s and 60s).

Lab results did not really surprise anyone. The test engine, designated as the K-310, responded exceptionally well to the modifications. In the first run with a slightly hotter than stock cam, along with the high flow heads and standard flow carburetion system. The Fire Power achieved 225 horsepower and 332 pounds of torque. Next using the mid range camshaft, which gave the best all around performance, the Hemi stepped up to 275 horsepower and 352 pounds of torque! In the final test, a high performance grind camshaft, along with the four carb high speed manifold was tested. The K-310 put out 308 horses with a twist of 361 foot pounds. Remember, the pistons were stock. So, just to settle the issue, the 12.5 : 1 pistons were installed. This combination spun out 353 horsepower and 385 foot pounds of torque.

Although personally satisfied, James Zeder maintained his composure. He wrote of the tests that "the basic Fire Power cylinder gives performance comparable with Indianapolis engines, which have been developed for power without regard to any other purpose." In conclusion, he stated: "we remain unalterably convinced that, in the battle of the combustion chambers, the spherical segment chamber has demonstrated unquestionable supremacy."

In the meantime, in 1952, the DeSoto Division introduced its version of the Hemi head V-8. It was a 90 degree design of 276 cubic inches and was rated at 160 horsepower. It resulted in 50,000 installations! While smaller, the DeSoto V-8 had all the same characteristics of the Chrysler Hemi.

Cadillac gave Chrysler a little "touch" in 1952 by upping the horsepower ante to 190 in its 331 V-8. It was achieved by a slight boost in compression ratio. Chrysler was not too concerned, the Chrysler was still faster. In fact, a 1952 Chrysler was "King" of the beach speed trials conducted by NASCAR at Daytona Beach, Florida.

The third and final version of the original Hemi design was introduced by Dodge Division in late 1952 as a 1953 model. It was a 90 degree design of 241 cubic inches that was rated at 140 horsepower.

The original Hemi in racingOne other notable thing occurred in 1953 that must be mentioned. An engineer who was involved in resolving problems with the Fire Power, who had become a key member of William Drinkard's team, made a proposal that Chrysler build a car around a high performance Fire Power that had excellent handling and unique styling. It was taken seriously, very seriously. Bob Rodger was instrumental in seeing the Chrysler 300 come to life.

Outside of the Chrysler Corporation, the Fire Power was used in some racing and as power plants for other car makers. Briggs Cunningham was one notable builder that saw the raw potential of the Hemi. His goal was to win the 24 hour race at LeMans. To qualify, he had to build 25 cars. He received some technical information assistance from Chrysler for his efforts, however, any engine modifications were done solely by him with parts he either built or obtained from other sources. He raced his cars for three years, and retired from the circuit in 1955. He did race in LeMans in 1952, finishing in fourth, a remarkable first effort.

For all his stoic outward appearance, James Zeder was immensely proud of the Hemi engine. He also had a desire to see it be used in racing applications. He had an eye on the Indianapolis 500, the greatest spectacle in racing at the time. He had the lab begin experimenting with the 331 Fire Power.

John Platner and Don Moore were deeply involved in building the "Indy" engine which received the designation of A311. It was built with 8 Hilborn fuel injectors, big valves and ports, streamlined big exhaust manifolds, and a sort of modified camshaft that made the engine make "burbling" noises at idle. Under the quise of testing tires for Firestone and Good Year, the engine was installed in an Indianiapolis special racer. With the A311 engine, it easily ran the same lap speeds as the specialized Offenhauser and Miller racing machines.

The true opportunity to put the A311 to the test came in June of 1954. Shortly after the running of the 1954 Memorial Day 500, Chrysler Corporation dedicated its Chelsea proving grounds. The first four finishing Indy drivers were invited to bring their racers over to christen the 4.7 mile long oval race track. With wide lanes, and banked curves, the drivers were able to hold their cars wide open all the way around. The single fastest lap that day was made at 179 miles an hour. Then the Kurtis Kraft tire test car with the Hemi A311 made a couple warm up laps. Coming out of the 4th turn, the driver opened the engine up. It screamed by the centrally located pits and timing stand. Its deep Hemi bellow could be heard all the way around the long track. When it went by the next time, it was rolling at 182 miles an hour. And then did it again, and then again. Mr. Zeder and his engineers were delighted. They knew that a stock block engine with push rod technology could easily compete at Indy, and most likely, easily win.

It was not to be. The news of the test was given wide publicity. In a flurry of activity, the engine size rule was changed to allow only a 272 cubic inch limit for stock engines. A slight increase in piston stroke easily achiesved the 272 size. However, down on power, it didn't qualify. It would not be the first time that rules were changed by sanctioning bodies when Chrysler came out to play.

1953 saw Cadillac reach out and "touch" Chrysler again. The Caddy V-8 now had an output of 210 horsepower. To add sting, Oldsmobile had increased its V-8 to have 165 horsepower. But it was Buick that prompted Chrysler to move quicker. Always considered the direct competitor to Buick, Chrysler saw GM's prestigious number 2 division introduce a 322 cubic inch V-8 that had a top output of 188 horsepower.

On the beach at Daytona in the NASCAR speed trials Chrysler Fire Power V-8 cars got beat out by Cadillac. The Caddy flew over the sand at 113 miles an hour. It snapped past the Chrysler reaching 60 in 11.3 seconds. For all its punch, the Oldsmobile took a back seat to the 1953 Dodge which set a record of 102 miles an hour. However, it wasn't that easy. Hudson with a big flathead 6 cylinder engine cleaned up on the racing circuit. In another notable first, Lee Petty, who had switched from Plymouth to the V-8 Dodge, gave the Dodge division it's first NASCAR victory. Petty had given Plymouth its first NASCAR win in 1949!

The 1954 model year saw the first stages of performance improvements in the Hemi engines from the Corporation. Chrysler Fire Power V-8s now had 195 horsepower by bumping up the compression ratio to 7.5 : 1. As well, it had another version with a four barrel carburetor that put out 235 horsepower. That beat out Cadillac which did make an increase to 230 horsepower. Buick increased its punch to 200 horsepower. Not to be left out, DeSoto also increased compression to boost output to 170 horsepower. But, Oldsmobile bored out the 303 to 324 cubic inches with an output of 185 horsepower. In line, of course, Dodge bumped the compression ratio for an increase to 150 horses.

Taking note of the previous year racing success, and shared information from Chrysler, independent supplier Offenhauser manufactured an aftermarket manifold for a four barrel carburetor that would fit the Dodge Hemi V-8. Whether this was done in conjunction with, or because of, Dodge's selection as the Indianapolis 500 race pace car has never been clarified. This became a dealer installed option. With the manifold and 4 barrel, the 241 cubic inch V-8 was estimated (no actual figures were given) at 180 to 185 horsepower.

Lee Petty drove a 1954 Hemi powered Chrysler to victory in Daytona and went on to win the NASCAR Championship. The big Chrysler also dusted the Cadillac in NASCAR speed trials, setting a record at 118 miles an hour.

The 300: a Hemi showcase and the first production car with 300 horsepowerOne of the biggest advances in automotive history was introduced in January 1955. It should have come as no surprise since Chrysler had already built a 300 (claimed) horsepower engine from the 331 Fire Power in 1951! It was used in the K-310 concept vehicle built by Ghia in Italy. In 1952, another concept car, using a similar engine powered the Ghia built C-200. Clear indications for the future.

Chrysler Corporation held its 1955 model year introduction five days after Ford and nine days after Chevrolet, in what was believed would be like saving the best for last. Virgil Exner's "Forward Look" seemed to have just dropped from outer space onto the Chrysler Corporation vehicles. If you put the 1954 cars alongside the 1955s, you would swear that there was no way that they could have been built by the same company. At my Dad's dealership, floor traffic was the heaviest that it had ever been. Yet, the real show stopper was yet to come.

January 7, 1955 was the date that dealers were allowed to place the C-300 on their show room floors. It was an absolute marvel. The first day, it was almost a mob scene! At our store, the show room was jammed all day long and every day thereafter for a whole week.

Bob Rodger's suggested concept in 1953 came through as he had envisioned. The Chrysler C-300 was the first production car to have 300 horsepower. It was unique. It was special. It generated enormous interest. It was the hottest thing on wheels at that time. It blew everybody away. It wasn't inexpensive by any means either. Base price was $4,035. Pretty steep in comparison to a fully loaded Plymouth that could be had for $2,246!

On the street, people would turn and stare when a 300 went by. Curiosity seekers would follow a 300 and bombard the operator with questions when they parked. When one did park, a crowd would gather around it. Hard to imagine, but that automobile created a special niche that was very unfortunately let go by Chrysler itself.

To achieve 300 horsepower, Chrysler followed established performance techniques. High flow heads with larger, cleaner ports and valves that were operated from a speciality camshaft, through solid valve tappets, bumped up compression to 8.5 : 1, combined with dual exhausts, and two four barrel carburetors. It was not exotic either. It was totally reliable, required no real special effort to operate, delivered a smooth but firm ride, and had some of the best brakes in the entire industry.

In one of the first road tests of the C-300, Tom McCahill, writing for Mechanix Ilustrated, wrung out the big Chrysler. He was effusive in his praise. He consistently got to 60 miles an hour in under 10 seconds. Out of his several timed runs, his average was 9.8 seconds. That was like a bomb shell! A record like running the four minute mile. He put the C-300 on a certain highway that he used and got up to 130 miles an hour before he ran out of road. He wrote about that by stating: "it was as strong as Grant's Tomb, and 130 times as fast."

In NASCAR, on the beach at Daytona, a completely stock C-300 confirmed Uncle Tom's finding by posting a 128 mile an hour timed run. It was the fastest vehicle there taking top speed honors. Tim Flock, driving a C-300, won the NASCAR Championship. All fitting tributes to the engine that Chrysler advertised as "the most powerful production car built in America" with "the greatest, safest power in any American car." Which it was!

Not to be forgotten were the sister Hemi engines from the DeSoto and Dodge divisions. The DeSoto Hemi was bored a little bit to make 291 cubic inches. With a four barrel carburetor and dual exhausts, it made 200 horsepower. Over at Dodge, the smallest version of the Hemi was also bored a little bit to make 270 cubic inches. A special modification engine package that was dealer installed pushed output to 193 horsepower and 245 foot pounds of torque.

The 1956 Fire Power saw some changes to continue to be at the head of the horsepower race. The 331 cylinders were bored out 0.130 of an inch which gave an increase in cubic inches to 354.06. The camshaft specifications remained the same as did the valves. Compression was raised in an altered set of heads to 9.0 : 1. The exhaust manifolds were changed to encourage higher flow rates. It gave the 300B a rated horsepower of 340. Additionally, an optional set of heads that were installed at the dealer level bumped the compression ratio to 10.0 : 1. That gave the 300B a 355 horsepower rating. It also made it the first production engine to exceed one horsepower per cubic inch. Chrysler wasted no time to point that out. Tom McCahill was again enthusiastic about the 300, calling it "motorized dynamite, a connoisseur's car not meant for timid driving" and "Unmatched in a class by itself."

Mr. McCahill, who owned several 300s for his personal cars, of which was one of the first 1955 C-300s, also praised the suspension and handling qualities of the 300B by adding: "these cars hunker in to a corner like a starving dog clamped on a bone." The engine wasn't all there was to the 300: he called it the "best handling car I have ever driven straight from the show room." Over several timed runs, Uncle Tom got an average 0 to 60 mph times of 8.2 seconds.

With the new 355 horsepower V-8, the 300B allowed Chrysler to again clean up the beach at Daytona. It set a new record of 139 miles an hour. Tom McCahill pointed out that running on wet sand was not a real good way to determine speeds. He was correct in stating that it in no way provided the best surface for traction. His own speed tests on a dry asphalt road got very near 140 miles an hour with the 340 horsepower engine. Buck Baker was crowned NASCAR Champion driving a 1956 Chrysler 300B.

The Hemi also powers DeSotos and DodgesChrysler also paid attention to the two other Hemi engines in its corporate stable. The DeSoto got a new raised block with a 3.72 inch bore and a 3.80 stroke it made 330 cubic inches. With a power pak option, it had an output of 255 horsepower. But it wasn't quite over for the 1956 DeSoto Hemi engine. Introduced as a late edition, the new Adventurer model had its own unique Hemi.

A small bore increase to 3.78 inches in the 330 came out to 341 cubic inches. Output rose to 320 horsepower - pretty close to the Chrysler Hemi. DeSoto brought a couple of cars to the Daytona Speed Week; however, after the Adventurer made a run of 144 miles an hour, it mysteriously had major engine problems and did not return. Perhaps a politically correct move so as to not embarrass the 300? Shortly after, a DeSoto Adventurer convertible was chosen to pace the Indianapolis 500.

Sister Dodge also introduced a new raised block that had a bore of 3.63 inches combined with a stroke of 3.60 inches which translated into a 315 cubic inch displacement. In standard trim, it was rated at 218 horsepower. There were two other factory options available. One was a 230 horse offer, and the other gave out 260 horsepower. As well, in what seemed to be a standard at Dodge, a dealer-installed option which consisted of a twin four barrel carburetion manifold was also offered. No figures were made public, however, it was generally accepted that this engine made 290 to 295 horsepower. In the newly introduced D-500 trim, that option turned the Dodge car into a racing terror at drag strips all over the country. It also propelled the 1956 Dodge down Daytona's beach at 130 miles an hour.

1957 was a banner year, especially at the Chrysler Corporation. Industry leading styling combined with industry innovative engineering sent the public clamoring back to Chrysler Corporation dealer showrooms in droves. A hotly debated issue concerned the body quality of all Chrysler divisions in 1957. In actuality, the 1957 styling was intended for introduction in 1960. Virgil Exner pushed to get the 1960 style introduced in 1957. Engineering did not have much time, so a whole lot of corners were cut to get the cars on the production line. Fit and finish left much to be desired. Inappropriate rattles, squeaks, wind noise, and terrible water leaks were built right in! Each car sold to a friend in 1957 turned them into enemies within a few short weeks! However, in all fairness, it should be pointed out that by doing so, Chrysler then dropped itself to the approximate level of the norm of the rest of the American auto industry. Ford was no better, and may have actually been worse. Chevrolet seemed better because they produced so many cars, in reality they were not of any better quality.

The area that the 1957 Chrysler Corporation shone in was the hardware underneath those "rust in place" bodies. Just as an aside, my Grandpa used to tell my father that "he couldn't sleep at night for hearing all the cars on the lot rusting." I don't think my Dad was too amused.

The Fire Power was boosted again in displacement by boring to 4.0 inches and stroking to 3.90 inches. That equated to 392 cubic inches. In standard form it belted out 325 horsepower. Remember, this is still the same block introduced in 1955.

For the new 300-C, the output went up to 375 horsepower. Higher compression heads made 390 horsepower.

Along with the new bodies came the torsion bar suspension, and the ultimate in automatic transmissions, the Torqueflite three speed.

Tom McCahill again went enthusiastic about the performance. Utilizing several runs, he whipped the big car from 0 to 60 mph in an 7.8 seconds. On his "private" public highway, he made 140 miles an hour. He praised the handling due to the torsion bar set up, claiming that it "set into a groove better than a needle on a record." He effused that the 300 series were a collection of "beautiful brutes" suggesting that they were for "hairy chested drivers." He went on to describe the driving experience as about as "subtle as wearing velvet boxing gloves."

With the 300C, Chrysler again lead the way at the Daytona Speed Week. However, the performance was off, with the fastest 300 making a one way run of 138 miles an hour. At first the Chrysler engineers thought that the beach surface, which varied from year to year, was the culprit. Certain that they had a 145 mile an hour car, they took the same car to the Chelsea Proving Grounds outside the Chrysler Headquarters. Opened up on the 5 mile track, the 300C only made about 140 miles an hour. The driver reported a heavy wind whistle at high speed. Finally, it was recognized that the windshield trim for the front of the roof stuck out nearly an inch, making it a very effective air brake. Using clay they formed the top of the windshield into a smooth, clean shape with no edges. The same car went out and ran 146 miles an hour with the clay covering the windshield trim.

The 392 C300 engine (used only in the 300C)

Not forgetting its other Hemi engines, Chrysler boosted DeSoto and Dodge in 1957. The 1957 DeSoto was bored out slightly again to 3.80 inches with a 3.80 inch stroke, a totally "square" engine. It measured 345 cubic inches. With two four barrel carburetors, it also produced 345 horsepower, an industry first. Chrysler did not capitalize on it as it should.

Technically, yes the 300B made more than one horse per cubic inch, however, that was a specialized optional engine. And yes, Chevrolet was crowing about their new 283 ci V-8 making 283 horsepower. But, in contention, that too was a specialized engine, and a $536 option at that! Big money in 1957. The DeSoto 345, on the other hand, was a "standard" engine that required no special order or checking an option order to obtain it. These were great performance cars in their own right. An Adventurer with the 345 was good to get to 60 in 8 seconds. It was tested by Mechanix Ilustrated and Motor Trend where both testers obtained top speeds of 140 miles an hour.

Dodge too received its share of attention. The 315 Hemi was bored to 3.69 inches with a 3.80 stroke that came to 325 cubic inches. It was available with three different power choices. Standard was 245 horsepower. Stepping up with increased compression, you could get 260 horses. Optional for the D-500 the 325 output was measured at 285 horsepower. As had become usual practice, a dealer installed manifold and dual four barrels boosted the 325 to 310 horsepower. However, the new body style did not lead itself to racing as had the 1956. Dodge cars were losing out. Quick action by Dodge management made the Chrysler 354 Hemi available as an pricey extra cost option. It helped performance without a doubt. However, for Dodge 1957 was an off year performance wise.

With quality problems looming extra large early in the 1957 model year, not much money was allocated to restyling for 1958. To its credit, Chrysler engineering was engaged in a crash "reverse" engineering project to improve quality so as to end the death threats that had been received. They were successful, in many respects, especially for ending the water and dust leaks. Somewhere, along the way going into 1958, a little bit of sting was lost, and Chrysler no longer actively sought the performance image; perhaps it sought to not draw as much attention to that due to the high incidence of poor quality control exhibited by the 1957 models. Most of the Corporation cars stood pat for 1958, so the public still saw quality problems in the same style cars.

The first-generation Hemi fades awayThe former fierce growl of the Hemi was about to be silenced. 1958 was the last hoorah. The 300D had the same engine as the 300C, except the D was rated at a standard 380 horsepower. Experimenting with fuel injection, Chrysler had Bendix build an electronic system that produced 390 horsepower from the 392 Hemi. It was troublesome and only 16 cars had it installed; all were changed to carburetors for free by Chrysler.

One of the design changes was a new windshield that rolled up into the roof, eliminating the troublesome trim of 1957. However, it really didn't make that much difference. The Hemi had reached its safe limit for boring out. As well, the manufacturing process for the 1958 engine run had changed. The hardened crankshaft was replaced by a drop steel forged unit. The optional "chassis package" was not offered. The rear axle ratio options were drastically reduced.

At the Daytona Speed Week, the 300D was obviously not what the earlier marques had been. It won the flying mile, but was beaten by Pontiac for top speed, although the Pontiac was still not up to the 139 mile an hour mark set by the 300B in 1956. Tom McCahill still called it "America's best sedan." He could whip the 300D to 60 in 9.0 seconds. A sign of the times in that the 1957 and the 1956 could outrun the 1958. The "D" managed a top speed of 135 miles an hour.

There was only one other Hemi engine left in 1958. That belonged to Dodge. It was the 325 cubic inch model. It was sad because it was relegated to mundane hauler duties in two different tunes. The first had a rating of 252 horsepower and was standard in the Coronets. The step up was 265 horsepower and that was the standard engine in the Royal. The top engines were now wedge heads. Dodge had two in different configurations.

DeSoto made no pretext in 1958. Its Hemi bellow was forever silenced. Now it made due with two wedge head V-8s that were "corporate sized," displacing the same as Dodge.

For 1959, Chrysler Corporation no longer offered the Hemi in its Chrysler marque cars. However, the Hemi wasn't quite gone yet. The standard engine in the Crown Imperial (yes, the top of the line) was the 325 horsepower 392 Hemi V-8. But that was the end for the first generation Hemi engines, at least the ones built by Chrysler.

For a great display of some real cherry first generation Hemi V-8s stop by the Don Garlits Museum of Speed in Ocala, Florida. Don loved those engines. All of his "Swamp Rat" dragsters were powered by the Chrysler Hemi. He also built several stock appearing Fords that had the Hemi stuffed under the hood. They are on display too.

So great was the potential of the Hemi V-8 that two specialty manufacturers sprang up, devoted to building only that engine! A host of aftermarket parts were manufactured solely for the Chrysler Hemi engines. The Hemi headed Chrysler based V-8 engine is solely responsible for virtually all the drag racing records in the world. You cannot compete in the top fuel categories in any class in the IHRA or the NHRA unless it is a Hemi V-8! Reportedly the horsepower generated on specialized high potency fuel reaches upward of 6,000! I think James Zeder is still smiling, wherever he is. Bill Drinkard is probably with him and just as proud too.

While they may be rather rare today, there are still some undiscovered first generation Hemi V-8 engines out there waiting to be reborn. They were not just used in cars, either. Dodge trucks had them. Many farm applications like sprayers and water irrigation pumps had them. They also powered several manufacturers' boats. And in a very special application, they cranked up the Federal mandated civil defense sirens in big cities, towns, and villages all across America in the 50s and 60s. Check those wrecking and junk yards closely. You never know.

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