60s Impala SS with 409 V-8 a mythic performer
'She's real fine, my 409,' sang Beach Boys by Bill Vance (Toronto
Star, 7/23/94)
Chevrolet's revival of the Impala SS nameplate, using the
Caprice Classic as a base, is a good reason to look back at the
original 1961-69 Impala SS.
When the first SS (for Super Sport) was offered in 1961, it
was just an option package available on the then-top series
Chevrolet Impala. But it proved so popular that it became its own
series in 1964.
Chevrolet redesigned its full-size cars for 1961, virtually
eliminating the bat-wing fins that had soared in 1959, only to be
toned down for '60.
Reversing a trend to larger cars, the '61 Chevy was 1.5 inches
(38 mm) shorter, 2.4 inches (61 mm) narrower and some 50 pounds
(23 kg) lighter than the '60.
The curvature of the windshield was also reduced
significantly, thereby getting rid of those dogleg knee-knocker
windshield pillars.
Externally, there wasn't much to distinguish the SS from
regular '61 Impalas. Spinner wheel covers and three double-S
badges, one on each rear fender and one on the deck lid, were the
outside clues.
Underneath, however, it was a different story.
The original purpose of the Super Sport was performance.
Therefore, the base engine was Chevy's 348 cubic inch (5.7
litre), overhead valve V-8, offered in 305, 340 and 350
horsepower versions.
The real stunner, however, was the new 409 cubic inch (6.7
litre), 360 h.p. V-8. This was the engine that would really
establish the SS's credentials and inspire a Beach Boys song
entitled 409 ("She's real fine, my 409 . . .").
The 409 was derived from the 348 cubic inch eight that had
appeared in 1958. It was decided to develop the 409, originally
conceived as a truck engine, as an option for the bigger, heavier
Chevy car models.
By the time the engineers got finished with the 409, however,
much of its 348 heritage had disappeared.
Due to problems, only a few 409s were produced in 1961.
But the big V-8 returned for '62 with a new, stronger cylinder
block. Power was up to 380 h.p. with one four-barrel carburetor,
or an earth-shaking 409 horses when fitted with two four-barrels
and other modifications such as solid valve lifters.
The engine thus met the then magic figure of one horsepower
per cubic inch of engine displacement and would later exceed it
with a 425 h.p. version.
Chevrolet engineers didn't just give the Impala SS more power,
they also included such important items as stiffer suspension,
power steering and heavy duty power brakes. Special interior trim
was also part of the package.
The 409-equipped SS soon established itself as the hot one at
dragstrips.
Car Life magazine tested an Impala SS with a four-speed manual
transmission in its March, 1962, issue.
The testers reported 0-to-60 m.p.h. (96 km/h) acceleration in
7.3 seconds and 0-to-100 (162) in a mere 17 seconds. They
estimated top speed at 125 m.p.h. (200 km/h) with the 3.70:1 rear
axle in the test car, but felt that 150 (240) was possible with a
3.08 axle.
Once the Impala SS reputation had been established, Chevrolet
did what so many others have done: it traded on the fame of the
nameplate. The Impala SS package became available with Chevy's
smaller V-8s and even the six.
But the marketing men apparently knew what they were doing; SS
sales were approximately 100,000 in '62, then climbed to more
than 150,000 in '63.
When the Impala Super Sport became its own series in 1964,
more than 185,000 of them would be sold. Of this total, some
8,500 were fitted with the 409 V-8.
Chevrolet introduced all-new bodies for 1965, and Impala SS
sales soared to a record 243,000, the vast majority of them
fitted with V-8s. This would also be the last year for the 409
engine.
But thanks to the Beach Boys' song, the 409 had gained a
legendary reputation, despite having a production run of only
five years in which fewer than 44,000 had been built.
Several factors probably contributed to the declining
popularity of the Impala SS, whose sales slid to 119,000 in 1966,
then fell to 76,000 in '67.
First, the Chevrolet Caprice gradually displaced the Impala as
Chevy's top model. And the performance image was moving to the
smaller muscle cars, pioneered by Pontiac's 1964 GTO, and the
pony cars launched by Ford's Mustang the same year.
The SS would go back to what it had been originally, an
optional package on the Impala. Sales dribbled off to practically
nothing, and it was quietly discontinued in 1969.
In its nine-year run, however, the Impala SS established a
strong image and an enthusiastic following. It is still very
collectible, especially when fitted with the relatively rare 409
engine, forever immortalized in song.
Bill Vance, a freelance writer and historian, writes weekly on
our automotive past.