It was a fad of the times. All the major automobile
manufacturers were getting on the bandwagon, and AMC was right
there with them. Auto makers were crazy about aluminium engines.
And AMC was the leader in presenting a die-cast aluminium engine to
the public. Yes, AMC again scooped the field with the introduction
of its aluminium 196 six cylinder engine in 1961. America's first
die-cast aluminium block six. The new engine was backed by six
years' of design experience with die-cast aluminium engines and 2
million test miles on proving grounds, highways and the track.
The die-cast aluminium alloy cylinder block weighed only 60 pounds
and reduced overall front end load by 80 pounds due to lighter
component and suspension requirements. Precision, high-pressure
die-casting processes assured absolute uniformity and high
quality.
Centrifugally cast iron cylinder liners with a wall thickness of
.093 inches were mechanically and chemically permanently bonded to
the aluminium block. Hydraulic valve tappets and full flow oil
filter were added to assure quiet operation and a long life.
Topping off the aluminium engine block was a cast iron head
featuring integral valve guides and new exhaust valves. The main
and connecting rod bearings were steel-backed copper-lead alloy for
longer service life.
In addition to the 2 million miles of testing AMC subjected the
aluminium engine to on proving grounds, AMC put the new engine
through a million mile test at Daytona International Speedway under
official NASCAR supervision. Running night and day, week after
week, ten Ramblers powered by the new aluminium block engine piled
up a total of 1,000,000 miles of gruelling, high speed driving to
prove beyond any question the superb durability, economy and
performance of the most advanced engine on the American road.
Although the specifications of the aluminium engine and the tried
and true iron block six cylinder engine were identical in all
respects, there was no similarity in outward appearances. For one
thing the aluminium engine was unpainted.
For the first year of its introduction, 1961, the aluminium engine
was offered as an option on Deluxe and Super models of the full
sized Rambler Classics. AMC wanted to test the water before leaping
in. Nevertheless, the aluminium engine was made available for fleet
applications in the Rambulance and in taxicabs, which demonstrates
a high degree of confidence in the new design.
Through its press releases, AMC disclosed more about the aluminium
engine than is to be found in its sales literature and dealer
specifications books. The press releases disclosed that the lighter
engine permitted better balance and weight distribution which
promoted greater stability and easier handling. The new engine was
the result of a co-operative research and development program
between American Motors and the Doehler-Jarvis Division of National
Lead Company. Doehler-Jarvis was responsible for the production of
the aluminium blocks in its Toledo, Ohio plant. The block was made
of a special aluminium-silicon alloy for hardness and controlled
temperature expansion. Hydraulic valve lifters were used
exclusively for quiet operation and a newly designed oil pump
eliminated the possibility of hydraulic lock and assured proper
pressure calibration. A full-flow oil filter was standard
equipment. The new engine demonstrated improved performance which
was attributed to a redesigned intake manifold which provided
increased fuel-air velocity. The crankshaft was completely balanced
for smooth vibrationless performance. During the developmental
stage of the aluminium engine, it was tested by the use of the
latest aircraft industry method of applying cemented plastic with
polarised light to establish static and dynamic stress points.
Unfortunately, available production information does not disclose
how many aluminium engines were installed in Deluxe and Super
Classics in 1961.
By the time the 1962 Rambler Classics were introduced AMC was able
to say that the aluminium engine had been subjected to over 3
million miles of owner use. From this figure it is possible to make
a rough guess as to the number of these engines installed as
optional equipment on the Classic Deluxe and Super models. Assuming
that the average driver in 1961 drove approximately 12,000 miles a
year and adjusting this figure to compensate for the fact that some
cars were bought when first introduced and others toward the end of
the 1961 sales year, we could say that about 500 engines found
buyers. However, of this 3 million miles, 1 million had already
been driven by AMC on the test track. We are now down to around 300
engines sold. For all the effort that went into the development of
this engine, those sales figures are very disappointing, to say the
least. To help boost sales, AMC now made the aluminium engine
standard equipment on the 400 series of the Classic, while it
remained an option on the Deluxe and Custom lines. For those
customers who really did not want the aluminium engine,, the old
reliable cast iron six was available on the 400 line as an option,
presumably at no cost. Other than this change, everything remained
the same. If all Classic 400 models sold in 1962 were equipped with
the standard aluminium engine,, there would have been 58,057
aluminium engines sold in 1962. Even if a fraction of the cars in
1962 actually were equipped with the aluminium engine, the total
installed would have been significantly greater than the 300 plus
we have estimated for 1961. Though the press releases in 1961
stated that full-flow oil filters and hydraulic valve lifters were
used, the data books tell us another story - solid lifters and
partial-flow filters were standard.
For 1963 the aluminium engine was standard on the Classic 770 and
optional on the 550 and 660. The cast iron six could be had at no
extra charge in place of the aluminium engine on the Classic 770.
With the introduction of AMC's new Tri-Poised Power for 1963, the
engine mounts on the aluminium engine were changed to accommodate
the new method of suspending the engine on the chassis. Just over
60,000 Classic 770 models were sold in 1963. As with the 1962 sales
on the 400 line, it is doubtful that they were all equipped with
the aluminium engine. And, available production figures support
this fact. There were 45,998 1963 Classic 770s equipped with the
aluminium engine, which accounted for just over 76% of those sold.
When we look at the number of those cars that have survives today,
it is immediately apparent that the engine must have been quite
troublesome. The Classic 770 with aluminium engine today is a very
rare automobile indeed. If we assume the same percentage of
aluminium engines were installed in 1962 as in 1963, we can arrive
at a figure of 43,000 for 1962. Again, the survival rate is very
low.
The last year for the aluminium engine was 1964. AMC introduced the
new cast iron 232 cid six cylinder engine in 1964 and it replaced
both the aluminium and cast iron 196 cid engines in 1965. For 1964
the aluminium engine was optional on all Classics and no longer a
standard engine in any AMC. Exactly 4,939 aluminium engines were
installed in 1964 Classics. Apparently the durability of the engine
had not proven to be what AMC had hoped. From the comments of
owners within AMCRC it seems that the engine was technically a good
design and that quality of construction was satisfactory. The
problem was the combination of cast iron head and aluminium block
which caused problems due to electrolysis and differing rates of
expansion and contraction. Also, owner maintenance of the aluminium
engine was a cause of failure. The aluminium engine required more
stringent compliance with the maintenance schedule than the cast
iron engine, and owners either were not clearly advised about this
special requirement, or they just treated the engine as they would
have treated a standard cast iron engine. Unfortunately, if the
engine coolant got low or the car over heated, damage to the
aluminium block was almost a certainty. A cast iron block was much
more forgiving and that is the way most people probably got into
trouble with their aluminium engines. When an owner did experience
difficulties with the aluminium engine, dealerships would usually
replace the engine with a cast iron substitute rather than attempt
repairs. All in all, it was a noble experiment but a big
disappointment for AMC. A bitter pill swallowed quietly. There is
nothing we have available from AMC that discusses the demise of
America's First Aluminium Block Engine.
