MUSCLE CAR MANIA: Mopar* or No Car

The engines that powered classic Mopar* muscle cars live on as legends. Here are a few standouts.

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Brad Nelson
by Brad Nelson
May 10, 2024

Driving a muscle car came with ground rules. Every traffic light is a drag-racing tree. You must accept your addiction to the rumble and power. And having all that horsepower underfoot puts you in a cult of speed fanatics

Mopar* helped launch the muscle-car movement in 1955 with its bar-raising 300-horsepower Hemi* V-8 engine. By the 1960s, the muscle-car era was in full force with major automakers competing to make the sickest, fastest cars on the strip. But some would argue that the late-’60s/early-’70s were the standout Mopar years, when vehicles from Dodge,* Chrysler,* DeSoto,* Imperial* and Plymouth* were putting out eye-popping, rubber-shredding muscle cars and “Mopar or no car” was a rallying cry. Cars like the 1968 Charger* in “Bullitt” with Steve McQueen, the 1969 Charger in “Dirty Mary, Crazy Larry” and the white 1970 Dodge Challenger R/T* in “Vanishing Point” became stars of the big screen. And the engines that powered those seductive, two-door beasts live on as legends. We take a look under the hoods of some of them here.

276 FirePower Hemi V8

The Chrysler 1951 FirePower* Hemi V8 used a hemispherical combustion chamber engine design that produced 180 horsepower. Dodge, DeSoto and Imperial also had their own variants of the Hemi engine. The bore-spacing of Chrysler FirePower engines was 4.5625 inches and most used a two-barrel carburetor. However, the 1955 Chrysler C-300 was equipped with dual Carter* WCFB four-barrel carburetors and was rated at 300 hp, a head-turning number for the day. The FirePower Hemi also laid the foundation for the second-generation Hemi we’ll discuss later.

383 B-Engine V-8

In 1958, Chrysler introduced the B-engine* big-block to replace the first generation of FirePower Hemi engines. The most powerful B-engine was the 383, with a bore of 4.25 inches and a stroke of 3.375 inches. The engine generated power through high rpm, which made it a more popular option than the larger, but lower-revving, 426 Hemi or 440. By 1970 the 383 Magnum* boasted a peak output of 335 hp and 425 lb-ft of torque. It was used in a variety of Mopar muscle cars ranging from the Dodge Charger to the Plymouth ’Cuda.*

413 Max Wedge V8

The Chrysler 413 raised block, or RB,* engine was briefly the most powerful Mopar engine in production. Introduced in 1959, the 413 had a 4.18-inch bore and 3.75-inch stroke. It was initially used in Chrysler luxury cars, but in 1962, the 413 was reworked into a limited-production, high-performance engine known as the 413 Max Wedge,* named for the shape of its combustion chambers. The 413 Max Wedge had Driving a muscle car came with ground rules. Every traffic light is a drag-racing tree. You must accept your addiction to the rumble and power. And having all that horsepower underfoot puts you in a cult of speed fanatics. MUSCLE CAR MANIA: MOPAR OR NO CAR JUNE 2023 | 15 MAGAZINE a displacement of 425 cubic inches and featured solid lifters, dual-valve springs, magnafluxed rods and shortram induction manifolds. With an 11.0:1 compression ratio, this engine had an output of 415 hp and 470 lb-ft of torque.

426 Max Wedge

The 426 Max Wedge was a larger variant of the RB engine. It was introduced in 1963 with a 4.25-inch bore and three compression ratios of 11.0:1, 12.0:1 or 12.5:1 depending on the configuration. The “Stage III” 426 Max Wedge featured high-flow cylinder heads, severe-duty casting blocks with improved oil feed, a cross-ram intake manifold, two Carter 4-barrel carburetors and a high-flow, cast-iron exhaust manifold. It put out a factory-rated 425 hp and 480 lb-ft of torque to give it plenty of street cred and serve as the go-to high-performance engine until the birth of the 426 Hemi.

426 Hemi V-8

The 426 Hemi is arguably the most important V8 ever produced. It brought the muscle car to new levels of power and remains the standard to this day. The engine design was a “Frankenstein” of two engines, an enlarged 426 Max Wedge married to hemispherical-head technology from the 1950s Chrysler FirePower Hemi. The engine dominated the 1964 race season, including the top four spots at the Daytona 500, making cars like the Dodge Charger and Pontiac GTX* the stuff of legend. However, NASCAR* banned the competitiononly engine until it was approved for production, causing Chrysler to sit out the 1965 NASCAR season while they designed a street version. The engine stayed in the NHRA,* where it birthed a generation of advanced, hemi-headed engines that are still in use today

To make it work for the street, Mopar dropped the compression ratio from 12.5:1 to 10.25:1, used cast-iron heads instead of aluminum, backed off the timing, relaxed the camshaft and redesigned the intake and exhaust manifolds. The 426 Hemi was advertised at 425 hp and 490 lb-ft of torque, and 450 hp and 472 lb-ft of torque when equipped with twin Carter AFB carburetors. Legend holds that the 426 Hemi could actually generate upward of 500 hp, but Dodge officially claimed 425 to ease insurance premiums for prospective owners. Circumstantial evidence includes a 426 Hemi-powered Dodge Daytona* that became the first production car to reach 200 mph on a closed circuit. Iconic Mopars like the Plymouth Road Runner,* Plympouth Superbird* and Dodge Charger all housed a 426 Hemi V8. But opting for the monstrous engine nearly doubled the price of these cars on the lot, which explains why just under 11,000 production Hemis made it into muscle cars and why they can fetch seven figures at auction today.

Chrysler 440 V-8

The Chrysler 440 was the last iteration of the B-engine and one of the most iconic muscle-car engines of all time. Although not as exotic or rare as the 426 Hemi, the 440 delivered similar performance at a fraction of the cost. It was designed with a precision cast-iron block, light-wall construction, iron heads and a round bore of 4.32 inches with a 3.75-inch stroke. With the “Six-Pack*” configuration that consisted of a 10.3:1 compression ratio and aluminum Edelbrock* manifold topped by a trio of Holley* 2300 series carburetors, the 440 could churn out 390 hp and 490 lb-ft of torque during the 1969 to 1971 model years. The 440 came standard in the Dodge Charger R/T, Dodge Coronet R/T* and Plymouth Belvedere* GTX,* and was an option in the Dodge Super Bee* and Plymouth Road Runner

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Protect Your Mopar Muscle

If you’re lucky enough to revel in the power of a legendary Mopar V8, protection is critical. Here’s a list of AMSOIL products to help keep your classic muscle car tearing up the street for years to come.

AMSOIL Break-In Oil

Freshly rebuilt engines should start off with AMSOIL Break-In Oil. It’s formulated with zinc and phosphorus anti-wear additives to protect critical components during the break-in period when engine wear rates are highest. It doesn’t contain friction modifiers to allow for quick and efficient piston-ring seating, an important aspect of the break-in process to ensure maximum power and engine longevity.

AMSOIL Z-ROD® Synthetic Motor Oil

AMSOIL Z-ROD® is engineered specifically for classic and high-performance vehicles to perform on the street and protect during storage. It features a high-zinc formulation that protects flat-tappet camshafts and critical engine components, along with a proprietary blend of rust and corrosion inhibitors for added protection during long-term storage. It’s available in 10W30, 10W-40 and 20W-50 viscosities.

AMSOIL Assembly Lube

As they say, a great engine isn’t built in a day. Partially assembled engines can sit idle for weeks or months at a time. During this process, an engine-assembly lube must be applied that will cling to parts and provide wear protection, inhibit rust and help prevent deposit formation. AMSOIL Engine Assembly Lube handles all of the above.

Miracle Wash® Waterless Wash and Wax Spray

AMSOIL Miracle Wash is a must-have for owners dedicated to keeping their vehicle’s appearance on par with its performance. Simply spray and wipe off to lift dirt away from the surface instantly. It leaves vehicles with a super-shiny finish that protects against dust, light dirt and harmful ultraviolet rays.

AMSOIL Gasoline Stabilizer

When it’s time to put her away at the end of the season, AMSOIL Gasoline Stabilizer is crucial to ensuring your ride is road-ready in spring. Gasoline can degrade in as few as 30 days. Treat your fuel tank prior to parking the vehicle for the winter to help prevent fuel degradation and poor engine performance when it’s time to fire it back up.

DOMINATOR® Octane Boost

Early V8 models were designed to use leaded gasoline. As a result, classic and collector autos often require the use of a lead substitute to preserve the components that were designed for the fuel of days gone by. AMSOIL DOMINATOR Octane Boost is excellent as a lead substitute in older vehicles. It increases octane up to four points, helping reduce engine knock, improving ignition and helping fuel burn more cleanly.

Engine Fogging Oil

Any engine facing storage or lengthy inactivity should be treated with a good dose of Engine Fogging Oil first. Giving the cylinders a shot of oil protects them from rust, corrosion and harmful dry starts when it comes time to fire up your hot rod or classic car the following season.


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by Brad Nelson

Brad Nelson is a staff writer for AMSOIL. Outside of work he enjoys family adventures, wilderness exploration and riding/wrenching on vintage metric motorcycles.

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