Vintage Car Life Road Test: 1966 Plymouth Satellite 426 Hemi – King Kong Arrives, In A Blue Three Piece Suit

The Mopar street hemi, a true legend among car enthusiasts, graced the automotive scene from 1966 to 1971. Though it made its exit with a riot of DayGlo colors and stripes, it entered the market quietly. The 1966 Satellite coupe, with its unassuming exterior, was hiding an astonishing 843 lbs of power under its hood. Only a couple of small badges on the front fenders and a discreet “426” on its stand-up hood “ornament” gave away its true potential. Stealthy and poised to conquer any challengers, the street hemi left an indelible mark.

As many may already know, the hemi engine made its debut in 1964 as a racing powerhouse and achieved tremendous success. Richard Petty secured his first NASCAR Grand National title that year with the hemi engine. However, Ford protested, leading to the ban of the hemi for the 1965 season and Chrysler’s boycott of NASCAR. To resolve the situation and ensure the hemi could still be used in “stock car” racing, Chrysler decided to offer a street version.

Transforming the racing engine into a street-legal powerhouse required some taming. Its racing tune, delivering an impressive 500-550 horsepower, was scaled down to 425 (gross) horsepower at 5000 rpm for the street version. However, it still boasted an impressive 490 ft-lbs of torque at a relatively high 4000 rpm. Various modifications were made, including a milder cam, cast iron exhaust headers, lower compression ratio, and a conventional intake manifold equipped with two 625 fcm Carter AFB four-barrel carbs. One key aspect of the hemi’s design was its ability to breathe, owing to its 2.250″ intake valves and 1.94″ exhausts, paired with smooth ports. This design was the essence of a hemi engine.

The primary drawback of the hemi engine was the weight of its large cast iron heads and the associated costs. The hemi option, which included mandatory heavy-duty suspension and brakes, carried a price tag of $1105 (equivalent to around $10,000 in 2022 dollars). It was certainly not an affordable choice.

In comparison, Ford’s FE 427 engine featured 2.03″ intakes and 1.65″ exhausts, while Chevy’s response to the hemi was the 427 big block with staggered “porcupine valves,” accommodating 2.19″ intakes and 1.89″ exhausts. The Ford 427 represented the pinnacle of the FE’s development, but it required the limited-production 429 Boss engine to keep up with its competitors.

According to one source, the street hemi actually delivered 433.5 horsepower and 472 ft-lbs of torque on the dynamometer. However, these numbers also reflect the gross rating. When installed (net rating), the engine was officially rated at 350 horsepower in the 1971 brochure, although its state of tune may have been slightly less aggressive by then. Nevertheless, in today’s world, 350 net horsepower would be considered average at best.

Before diving into the acceleration statistics of the hemi, it’s important to consider two factors. Firstly, this particular vehicle was purportedly a genuine stock car, unlike the extensively modified Pontiacs featured in magazines at the time. Secondly, it was equipped with a Torqueflite automatic transmission and a standard 3.23:1 rear axle ratio, not the preferred choice for street or drag racing enthusiasts, as it didn’t shift to third gear until reaching 82 mph. However, it did allow the car to reach a top speed of 130 mph.

Due to the hemi’s torque peak occurring at relatively high engine speeds, its performance was more impressive at higher velocities. While its 0-60 mph time of 7.1 seconds may not be exceptional, its sprint to 100 mph in 15.8 seconds provides a better indication of its capabilities. It consistently completed the quarter-mile in 14.5 seconds at 95 mph. Feathering the throttle at takeoff was necessary to prevent the relatively grippy Goodyear Blue Streak tires from engulfing the road in smoke. However, once in motion, the hemi delivered remarkable acceleration. Given the Satellite’s curb weight of 3940 lbs and its tested weight of 4350 lbs (with two occupants and instrumentation), the engine’s power was necessary.

The street hemi proved to be well-behaved during casual city driving, giving no indication of the monstrous power lurking under the hood. It was only when the throttle was pushed hard and the secondaries kicked in that its true nature was revealed.

One issue, however, was the braking performance. The large “police” 11″ drum brakes left much to be desired, particularly in regard to rear wheel lock-ups. This was primarily due to the absence of a weight-sensing proportioning valve, a feature that Detroit seemed to avoid. As a result, loss of control was an inevitable outcome.

Handling around town was satisfactory, although the Mopar power steering lacked road feedback. During spirited cornering on rural roads, the car exhibited some body roll and tire protests that were inconsistent with its overall behavior. It was not destined to be a nimble canyon carver, with the heavy cast iron engine resting over the front wheels.

The interior of the Satellite had two notable flaws. The console’s chromed/bright ribbed top surface created blinding glare under certain angles of sunlight. Additionally, the tachometer was mounted under the dash at the front of the console. Furthermore, the doors of the Satellite seemed to have been subjected to an earlier street race, requiring two forceful slams to ensure they closed properly.

In response to the question of who would invest in a street hemi, Chrysler stated that the 426 hemi was developed for a growing market of new car buyers, especially those with an active interest in sanctioned off-highway timed trials. The number of street hemis seen at drag strips was steadily increasing.

If I had the opportunity to travel back in time and choose any new hemi, it would undoubtedly be a 1966 model, either the Plymouth Satellite or the Dodge version. And perhaps, I would remove the “hemi” badges, allowing the car’s extraordinary performance to speak for itself.

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