Posted by MoparNorm on Thursday, April 29, 2004 at 10:59AM :
In Reply to: Re: Installed My Cab & Doors Today posted by Lucian Drumond on Thursday, April 29, 2004 at 10:02AM :
The early Chrysler V-8 were Hemis, plenty of power, but expensive (in those days) to build, compared with the I-6 that had been the Chrysler and Dodge staple motors for decades. It was thought that by eliminating the extra row of rockers and therefore the size of the head, that considerable savings could be realized. As it turned out the savings from going from Hemi to Poly was less than $35 per motor (sourced at Allpar) so Chrysler began developing the wedge and RB motors. The Poly lasted for less than 10 years, (approx. 7 in the US and 8 years in Canada). There was a small aftermarket speed equipment following (the whole aftermarket was small in those days) for the Poly as Edelbrock, Offenhauser, Weiand and others started making trick parts at about the time the RB's and the 1964 Hemi came out. At the time fuel was less than 33 cents a gallon and the big blocks soon reigned supreme. Only Weiand still makes intake manifolds for the Poly. The Poly was forgotten by nearly everyone.
Fast forward 35 years, Dodge enters Nascar with a new motor, a canted valve 358 cubic inch high performance motor than looks suspiciously like the Poly. The new 'Hemi' is closer to the 1964 Poly than to the original Hemi.
The Poly had the following; forged crank, nearly perfect balance between the intake runners and evenly spaced exhaust and intake ports. With relatively small valves the motor could produce 260 HP in stock form when equipped with a 4 bbl. The 2 bbl versions produced 200 or 202 depending upon engine internals, along with gobs (technical talk) of torque. Polys that are built have seen 455 documented HP and torque in the same range.
Go to Mopar Performance today and order a high performance oil pump for your LA motor and you will be handed a brand new 1961 designed Poly oil pump. While hard to find, there are sources for nearly every new part needed to make a Poly run as strong as any motor Ma Mopar ever built. They have been erroneously called "wideblocks" over the years, but the truth is, the LA series blocks are the same blocks up to the Magnum series, it was the heads that were wider, not the block. The heads were a tad smaller than the Hemi because the second rocker was eliminated, but the combustion chambers are basically Hemis. The elimination of the second rocker allowed the spark plug to be moved to a more conventional location but this caused the valves to be canted and that resulted in the heads getting the classic Poly Scalloped look. gm and ferd talk a lot about their "canted valve" high performance motors, but the Poly had that design years before it became popular. Every Nascar Cup motor is a canted valve motor, the Ramchargers would be proud!
MN
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