Mighty Mopar Muscle - The Engines
Page 5
The street Hemi's compression
ratio was lowered from 12.5:1 used for the racing Hemi to
10.25:1, using pistons with lower domes.
The intake manifold on the street
Hemi was an aluminum dual-plane design with two Carter
four-barrel carburetors mounted in tandem. Because the racing
cylinder heads had no provision for intake manifold heat, a pal r
of tubes running off the right exhaust manifold to the intake
manif old was needed to make the cold-blooded Hemi streetable.
A massive, chromed air cleaner
straddled both carburetors, instead of the individual air
cleaners used in the past.
Did someone ask about horsepower?
The 1966 street Hemi was conservatively rated at 425 hp at 5000
rpm, with 490 pounds-feet of torque at 4000 rpm. The street Hemi
was an expensive option, costing over a thousand bills in 1966
dollars. It was attractive to those who had to have the ultimate
in performance and image on the street, who more than likelytook
it to the drags on the weekends.
Because the Hemi was so highly
developed, the street version was improved in only two
significant ways during its production from 1966 through 1971 in
1968, the duration of the solid lifter camshaft was bumped from
276 to 284 degrees. The overlap was also increased, from
fifty-two to sixty degrees. In 1970, Chrysler switched from solid
to hydraulic lifters, which required less frequent tuneups. The
advertised horsepower and torque ratings were not changed,
however.
Designed for racing, the 426 Wemi
was a record setter wherever cars were raced. During the sixties,
Bill and Bob Summers were avid racers and Mopar supporters. Known
as The Summers Brothers, they embraced the Hemi as the ultimate
racing engine, even in stock trim. In 1965, they set new World
Unlimited Class and international Class A speed records with
their thirty-two-foot-long. streamlined Goldenrod, powered by
four fuel-injected Chrysler Hemis. On the Bonneville Salt Flats,
the 2,400-hp vehicle hit 409.695 mph for the Flying Kilometerand
409.277 for the Flying Mile. The following year, The Summers
Brothers returned to Bonneville with a Hemi-powered Plymouth
Satellite and set an American B/Production stock car record of
156.35 mph.
Despite the fact that Chrysler was
absent from the stock car ovals in 1965 due to a dispute with
NASCAR's Bill France over the 426 Hemi's production status,
records were still being set at Daytona. On February 26, 1965,
Lee Roy Yarbrough set a new closed-course record of 181.88 mph
with a fuel-injected and blown Hemi-powered Dodge Coronet.
NASCAR's most successful racer,
Richard Petty, didn't sit idle with his Plymouth on the sidelines
in 1965. He had a 1965 Barracuda specially fitted with a 426 Hemi
before he hit the drag strip circuit, and won B/Altered class
that year.
An even wilder vehicle seen on the
quarter mile was not a car, but a pickup truck. The Little Red
Wagon was one of the most popular drag racing rigs at strips
around the country. The brainchild of Dick Branstner, Roger
Lindamood, Jim Schaeffer and John Collier, The Little Red Wagon
was a Dodge A-100 compact pickup dropped onto a custom,
heavy-duty chassis with a mid-engine fuel-injected 426 Hemi for
power. Wheelstands were the rage at drag strips during the
sixties, and The Little fled Wagon performed them effortlessly
while setting ten-second elapsed times at 130 mph.
AIl across America, the 426 Hemi
not only became the engine to beat, but the engine to race.
Professionals and amateurs agreed it was the most powerful and
successful racing engine ever built. To list the races the 426
Hemi has won would be an impossible task.
That is a distinction that the 426
Hemi holds to this day. Chrysler stopped building the Hemi at the
end of 1971, but aluminum Hemi blocks and cylinder heads
manufactured by Keith Black and Milodon continue to supply an
insatiable market for this most famous of Chrysler engines.
The Chrysler 440-ci V-8 wedge
engine was the largest ever bolted into a Dodge or Plymouth. The
corporation introduced the 440 in 1966. It had a bore and stroke
of 4.32x3.75 inches. This engine, with a four-barrel carburetor
and 10.10:1 compression ratio, was not considered a
highperformance engine like the 426 street Hemi introduced that
year. There were two 440 V-8's in 1966. One developed 350 hp at
4400 rpm with 480 pounds-feet of torque at 3200 rpm, and the
other engine developed 365 hp at 4600 rpm with 480 pounds-feet of
torque at 3200 rpm. These engines were designed to power the
largest and heaviest Chryslers, Dodges and Plymouths. Chrysler
engineers saw the performance prospects in the 440 for the
growing high-performance street scene, and got to work.
In 1967, Chrysler introduced the
Super Commando 440 in a brand new performance car--the Belvedere
GTX. This same engine, called the 440 Magnum, powered Dodge's new
performance car, the Coronet R/T. The ad for the GTX touted the
engine's displacement status: "Supercar. And how! The
standard GTX powerplant just happens to be the biggest GT engine
in the world!"
The Super Commando 440 and 440
Magnum were meant to fill in Dodge's and Plymouth's performance
engine lineup, fitting in between the 383 and the 426 Hemi. The
440 started life as a bored 426 street wedge. This was a rugged
block and used forged crankshaft and connecting rods, but
Chrysler engineers saw no need for forged pistons. Most of the
development work for the high-performance 440 went into the
engine's induction system.
The first thing the engineers
tackled was the cylinder heads. These heads had ten percent
larger ports than those in the 1966 engine. The intake and
exhaust ports were redesig ned to smooth the flow of the fuel and
air mixture into the cylinders and spent gases out of the
cylinders. The in-take valve diameter stayed the same at 2.08
inches, but the exhaust valve diameter increased from 1.60 inches
to 1.74 inches. The intake manifold was redesigned to match the
increase in the cylinder head ports. Chrysler chose a Carter AVS
four-barrel carburetor to deliver the fuel. Atop the carburetor
sat a dual-snorkel unsilenced air cleaner.
This engine also received a
high-performance camshaft to complement the induction system. The
rather mild camshaft in the '66 440 was nixed for a hotter one
with 268-degrees intake duration, 286-degrees exhaust duration,
fifty-four-degrees overlap, 0.450-inch intake lift. and
0.465-inch exhaust lift.
The exhaust manifolds were unique
to this engine in 1967. These heavy-duty cast iron units had
smoother passages than those on the 1966 engine, although they
weren't as convoluted as those on the 426 Max Wedge or the 426
Hemi.
The undercar exhaust system was
patterned closely after that used on the 426 Hemi. The exhaust
manif olds emptied i nto 2'/2-inch pipes which fed into two
reverse-flow mufflers, ahead of which was a crossover pipe to aid
torque and reduce exhaust "rap." Tail pipes were 2%
inches in diameter.
This engine was rated at 375 hp at
4600 rpm with a stump-pulling 480 pounds-feet of torque at 3200
rpm. Compression ratio was 10.10:1. The 350-hp 440 remained, but
the 365-hp 440 was dropped in 1967.
In 1968, the 440 received
~designed cylinder heads having larger combustion chambers for
better emissions. The pistons were also redesigned, extending
farther into the combustion chamber to maintain the compression
ratio.
During the 1969 model year, Chrysler
released the most significant perf ormance engine since the 426
Hemi That engine was the 440 Six-Pack, The clever name was coined
by long-time Chrysler executive Moon Mullins, and Phil Ingledrum.
Six-Pack referred to the triple two-barrel induction system.
Choosing to go with this system was really a smart marketing
move. Chrysler had explored single four-barrel and dual
four-barrel carburetor systems, but had never used a triple
two-barrel setup on its B-block. Enthusiasts had always thought
such an induction system to be the ultimate on the street, and it
was used successfully on Pontiac's GTO and Chevrolet's Corvette.
The 440 Six-Pack was the obvious next step to take with the 440.
The foremost features of this
engine were the three Holley two-barrel carburetors that sat atop
a custom Edelbrock aluminum intake manifold, with a combined flow
capacity of over 1,200 cfm, nearly double that of the four-barrel
440. While cruising down the street or highway, the engine was
fed by the center carburetor having l%-inch barrels. Under hard
acceleration, the front and rear carburetors with 13/d-inch
barrels would kick in. The 440 Six-Pack had an open air cleaner
spanning all three carburetors.
In producing horsepower, the 440 Six-Pack
compared favorably with the 426 Hemi. The 440 Six-Pack developed
390 hp at 4700 rpm with 490 pounds-feet of torque at 3200 rpm;
the 426 Hemi didn't develop that amount of torque until 4000 rpm.
Street and strip races between a 440 SixPack and 426 Hemi were
sometimes close.
In 1970, the compression ratio on
the four-barrel 440 was dropped to 9.7:1, but was still rated at
375 hp. The compression ratio for the 440 SixPack remained at
10.5:1.
In 1971, both four-barrel and
six-barrel 440's dropped slightly in compression. The four-barrel
V-8 dropped to 9.5:1 and had 370 hp at 4600 rpm with 480
pounds-feet of torque at 3200 rpm. The 440 Six-Pack was rated at
385 hp at 4700 rpm with 490 pounds-feet of torque at 3600 rpm.
Its compression ratio was 10.3:1. This was the last year for the
440 SixPack.
For 1972, Chrysler adopted SAE net
horsepowe r rati ngs a nd lowe red compression ratios on all
engines. The 440 Six-Pack was scheduled for 1972 production, but
at the last minute Chrysler decided to drop it. The four-barrel
440 became increasingly rare, and wasn't even available in the
Dodge Charger or Plymouth Barracuda.
Horsepower continued to plummet
with each passing year. The 440 was eventually phased out of
passenger cars in the late seventies.
For detailed information please e-mail info@tommythekrycho.com