All,
This was posted to the Ram mailing list and with permission from the
original poster, I am posting it here for those that are interested in the
new engine. Please remember that I did not write this and am not a contact
for more info. I am only passing the info along. If you would like the full
article, you can read it in Mopar Action magazine, though I do not know what
month. The original poster asked that I remove his name as he is not sure
exactly what the copywrite restrictions are.
John
98 Dak 4X4 CC Sport, 5.2L, Auto, Mopar Headers, DDBC
The following is an article about the new 4.7L single overhead cam V8
written by Richard Ehrenberg of Mopar Action magazine, who also does their
technical advice column - where he can be reached at mrmopar@computer.net.
Notice the references to 'after all it's just a truck engine' and the
emissions comments.
The good news is that it does not have a rubber timing belt.
I am typing this as a three-part email: the first part gives some
interesting history of Mopar engines stuff, the second part with the heavy
duty tech details of the bottom end, and the third with topside: Heads and
Misc.
Please forgive typos as I am hand typing this on the kitchen table while
sweating out the flu.
And please think of this as a 'teaser' so that you will consider going out
and buying the magazine to get the great illustrations.
Chrysler's New Cammer
Tech analysis of Mother's first all new production V8 in 41 years.
by Richard Ehrenberg
Dateline: Highland Park, Michigan, fall 1957. The 1958 Dodge and Plymouth
are introduced with an all new, modern B-engine, the 350 and 361 cubic inch
V8 option - the very engine we've seen grow to 400 cubes, and, in its
tall-deck variety, the famous 440. Although spawning the all-conquering
426 Hemi, this series lived only through 1978, at which time it was an
innocent victim of corporate near-bankruptcy, emissions, and fuel economy
mandates. But who would'a thunk that it would take another 41 years - 1999
model year - before Chrysler would introduce another all new V8 engine?
But it's here - now. Since the new Power Tech 287 inch V8 (4.7L for you
metric fans) is designed to replace, initially, the famous 318 (5.2L)
Magnum mill, which, itself, was an outgrowth of the first smallblock
Chrysler engine in 1955, we'll begin with a brief history lesson.
The "A" engine, introduced in 1955, was Chrysler's first attempt at an
'economy' V8 engine. The Hemi, Chrysler's first V8, when introduced in
1951 at 331 inches, was anything but economical to manufacture: Complex
head castings, four rocker shafts, etc. So the A engine-ers tried to keep
some of the best features of the Hemi, but with pared down costs. A single
rocker shaft was mounted on each head, with opposed valves operated via
splayed puchrods. While this engine was never really a killer
performance-wise, it stood the test of time, and was produced by the
zillions through 1967. Most common was the 318 inch variety.
In 1964.5, a new, thinwall-block version was added to the A-stable.
With a 273 inch displacement, it was designated the LA engine. Modern
wedge-chamber heads would set the standard for decades to come. Over the
next 7 years, variants would include the 318 and 340 inch displacements,
with a larger main bearing 360 joining the rostrum last (1971). These
engines would continue, with incremental changes and updates (single port
EFI, roller cams) through 1992-1993, when the now common Magnum multiport
fuel injected update came on-stream.
The Magnums, though sharing very few actual components with its
predecessors, was still an LA engine, through and through. All key
dimensions: Bore, bore centers, bearing sizes, can-to-crank, etc., remained
just as they were in 1955 !
Which brings us to 1999. The new 287 is just that, new, sharing
almost nothing but a heritage with the ol'reliables. For starters, it's
the first true production Mopar V8 mill to incorporate aluminum cylinder
heads ( okay, we know about the 1965 A-990 Hemi ) a plastic intake
manifold, and magnesium valve covers. Nothing is re-hashed here, and the
combustion chambers are almost hemispherical !
And, although it might take a year or two, we'll bet that variants of
this powerplant - the "C" engine? - with more or less cylinders, and
varying internal dimensions will replace virtually all RWD gasoline
powerplants now in the Chrysler stable. In other words, this is a real
milestone. So let's take a detailed tour of what's what, what fits what,
and start some good rumors about where DC will take this engine in the
future. We'll begin at the lower extremities.
======================
end of part one.
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