Sergeant James Post
Obituary for a Legend
She was conceived in secrecy during World War II, but was not introduced to the public until 1951 when she was received with instant adoration. She soon became a legend, unlike anything seen before or since.
Sadly, we lost her in 2024, leaving behind a legion of brokenhearted fans, the majority with motor oil in their veins and grease under their fingernails. She died from a cabal of politics; global warming hype; bovine flatulence; misinformed do-gooders; foreign greed; a silver-haired condiment czar; a European teenage doom and gloom prognosticator; and, say it ain’t so, Reddy Kilowatt. She is the Chrysler® HEMI® V-8 engine.
The HEMI is so named because of its distinctive configuration of overhead hemispherical combustion chambers which place the spark plug at the center of the valve cover and the chamber to provide a strong flame. They are more sensitive to octane ratings, requiring higher grades to prevent pre-detonation.
There were three generations of HEMI engines developed by Chrysler: Gen One (1951 to 1958); Gen Two (1964 to 1971); and Gen Three (2003 to present).
The earlier WWII reference describes Chrysler’s first experimental HEMI engine, an inverted V-16 for the P-47 Thunderbolt fighter. The P-47 was already in service with a Pratt & Whitney radial engine, but, in spite of successful trials in 1945, the HEMI-powered Thunderbolts were never put into production or saw combat because the war was winding down. Chrysler and Continental did join up to develop a V-12 HEMI which was used in the M47 Patton tank.
Gen One – Birth of a Legend
The engineering success of both the V-16 and V-12 engines of WWII ultimately led to Gen One, the first V-8 HEMI, sold in the 1951 model year, in Chrysler, Imperial, DeSoto, and Dodge cars with valve covers proudly bearing the names, “FirePower,” “Firedome” and “Red Ram.”
331 – Chrysler classified their HEMI engines by piston displacement (Cubic Inches or CI), not horsepower, and that system continued through Gen Three. The first engine was rated at 331 CI and was used until 1955.
354 – The next upgrade took the HEMI to 354 CI and was built for the 1957 Dodge trucks, bearing the moniker “Power Giant V-8.”
392 – The next modifications took the HEMI to 392 CI and was available in two HPs, 325 and 375, depending on carburation (a single 4BBL or dual 4BBLs). An experimental Fuel Injection (FI) was attempted; however, due to only primitive FI control computers being available at the time, 15 of the 16 cars built with FI were recalled and the systems replaced with carburetors. The 392 engines were optional in Chryslers and DeSotos.
Gen Two (OMG) – the 426
The hemispherical head design was revived in 1964 and they were the first engines actually named HEMI, a name Chrysler had wisely trademarked earlier. The 426 designation was the actual cubic inch displacement and was nicknamed the “elephant engine” because of its power, heavy weight and humongous physical dimensions.
The 426 was originally built exclusively for NASCAR and raced in a 1964 Plymouth. It was not available to the general public and, for this reason, in 1965, it was banned due to NASCAR rules. Chrysler quickly put HEMIs in special versions of the 1965 Dodge Dart, Plymouth Fury and Dodge Coronet which were sold to the public, reinstating them in the good graces of NASCAR. In 1966, Chrysler introduced the “Street HEMI” for use in these models, but with lower compression than the NASCAR and drag racing “Race HEMI,” with dual 4BBL inline carbs and cast iron exhaust manifolds. In this era, “crate engines” were born and car guys with enough cash could buy their own 426 in a box from Mopar®.
The 426 “Street HEMI” was available from 1966 through 1971 in Dodges and Plymouths, in popular models bearing creative names like Charger, Super Bee, Super Stock, Daytona, Super Bird, Road Runner, Barracuda, and Challenger which today are fetching amazing prices at collector auctions.
The 426 HEMI became popular in drag racing at both NHRA and AHRA tracks (1/8 and ¼ mi), in addition to NASCAR. Drag racing cars were usually simple body-less “rail” dragsters, with engines either mounted fore or aft of the drivers. They were classified by the fuel used – either high-octane pump gas, nitrous oxide or alcohol duratives.
Full-bodied race cars which were modified with altered wheel bases and lightened bodies were often called “funny cars.” There were also factory sponsored drag race teams, such as Sox & Martin and the Ramchargers.
Drag strips with bleachers and timing stands attracted thousands of fans. Innovative owners sold “pit passes” to fans, allowing them access into the area where race cars were prepped or repaired. Enterprising strip owners often opened at night for “challenge races,” where, for a minimal fee, we could race whomever we chose. This became an all-new version of “date night.”
Gen Three – MDS and the LX Platform
The 5.7L HEMI was first released in the 2003 Dodge Ram pickups and engine ratings were switched from SAE to liters. The new HEMI introduced a unique coil-on-plug (distributor-less) ignition system, utilizing coil packs on each spark plug and two plugs per cylinder, resulting in a more consistent combustion and reduced emissions.
5.7 – In 2005, the 5.7L was mated to Chrysler’s new LX platform and the performance world changed forever. It became the sole V-8 engine available for the Chrysler 300 and Dodge Magnum.
In 2006, resurrecting an iconic nameplate, the Dodge Charger was added to the HEMI lineup. Unfortunately, diehard Mopar fans were disappointed because it was released as a four door so Chrysler could again compete in the police car field. But, in 2008, the nostalgia fan’s patience finally paid off with the release of an all-new Dodge Challenger.
That first 5.7L (345 CI) HEMI in the Ram delivered 345 hp, but, when added to cars, it had a couple new exciting features – one historical and one purely ornamental. First, Chrysler introduced a dramatic fuel saving device called the Multi-Displacement System (MDS) which shut off two cylinders on each bank under light load which improved fuel economy dramatically by smoothly switching the big V-8 from eight to four cylinders. MDS engages automatically up to at least 75 mph and even when using cruise control.
A purely aesthetic addition to the 5.7L was a plastic engine shroud which covered the fuel induction system, plug wiring and heads. The cover was emblazoned with two prominent “HEMIs” in two inch block letters. Car guys loved these covers and soon they were customized with pinstripes, artwork and painted in body colors.
The 5.7L would undergo several revisions in 2009, including tweaked cylinder heads (to increase flow) and reworked intake manifolds. Engines mated to six-speed manual transmissions did not include MDS. These mods increased horsepower ratings as follows: Chrysler C – 363 hp; Charger R/T – 370 hp; and Challenger R/T auto – 372 hp and, with a six-speed manual trans, 375 hp.
6.1L – At this time, a more potent HEMI was also available in SRT® packages. The optional 6.1L version produced 425 hp which was accomplished with an increased bore and stroke, a revised coolant channel, a forged crankshaft, lighter pistons, strengthened rods, and a cast aluminum intake manifold.
6.2L – For 2015, Chrysler introduced an all-new, high performance SUPERCHARGED variant of the HEMI, the Hellcat, named after the Grumman F6F fighter of the same name. Rated at 707 hp, this was the most powerful production engine ever put in an American muscle car.
In 2017, Mopar announced the Hellcat engine was available as a crate engine, known as the “Hellcrate.” A Challenger Redeye model, with a whopping 797 hp, was released in 2019, and it was followed by a Charger Redeye version in 2021.
But, the lead foot engineers at Mother Mopar also built another variant in 2018 named the Dodge SRT Demon, a bona fide street worthy race car packing 808 hp (on 91 octane pump gas) and 840 hp (on 100 octane racing fuel). A functional hood scoop was added and it came with a pair of racing slicks and rear seat delete.
The Cops Lose Again
Another victim of the HEMI assassination is American cops with their loss of the great Dodge Charger Pursuit police car (2006-2024) which was collateral damage in the stampede to build EVs. Like the terminations (by builder) of the Chevy Caprice 9C1 (1996) and the Ford® CVPI (2011), the Charger died long before her time. And, the real tragedy is the only people mourning the Charger Pursuit’s demise are our police because she was the last true RWD, 4DR, V-8 American cruiser.
Like the HEMI, the Charger police package production was divided into three generations, Gen One (2006-2011), Gen Two (2011-2015) and Gen Three (2015-2024). Of course, there were safety and performance improvements and style changes throughout the Charger Cop Car run, with the most significant addition being the option of AWD in 2015, making the Charger a true year-round police car.
Although I never had the opportunity to drive any of the three popular makes of American cruisers above during my career, I have been fortunate to own retired models of each brand and I found them all to be great cars. However, my favorite will always be the Charger. Yes, I’m a HEMI fan; I’ve owned eight and still own three and they’ll have to pull the fobs out of my cold, dead hands.
Adios and Farewell
Legend seems like an insignificant title for the Chrysler HEMI…like a phoenix rising from the ashes, the HEMI’s reincarnations and longevity are nothing short of amazing. There were several versions of the HEMI, with varying horsepowers, built right up to her 2024 termination, but, in her life of 73 years (minus two breaks of nonproduction), she – and Chrysler – continued and persevered through three owner/partner/merger changes (Daimler, FIAT®, Stellantis); three US government “rescue loans”; UAW strikes; the unibody fiasco and numerous frame and platform changes; a boycott by gay rights groups; asbestos lawsuits; bankruptcies; the dubious “gas crisis”; sales which charted like the US economy; and the loss of several popular marquees; and, still, she soldiered on. Through the decades, the famous Pentastar emblem (created in 1962) still stands proudly at the top of her corporate headquarters in Auburn Hills, MI.
But the HEMI’s true legacy was penned in oil by her loyal fans from back in the day…the owners; the builders; the race attendees; and those of us who lost money on every trade-in or suffered blown engines, hellacious insurance rates, clear coat peel, and rust. Mopar folks paid the price with patience, loyalty and pride and believed she would live forever. RIP
James Post wore several different LE badges for 27 years and has written about police cars for P&SN for 25 years. He always appreciates your comments, suggestions and even complaints. He can be reached at kopkars@arkansas.net.
