Why the early Hemis were discontinued (Was The Forward Look)

["Don Nonnweiler" <dnonnwei@xxxxxxxxx>]

It seems to me I recall a road test by Tom McCall where the 413 in a 59
Imperial  performed better than  then a 392 in a 1958 Imperial.  All I
stated earlier is that the ban on the hemi for racing by who ever was in
charge at the time, I thought it was AAA,but have been informed that it was
not so, was PART of the reason of the demise of the A-block hemi and that
there were many other reasons. I believe both of you misread my thread. To
most racing people the hemi had more potential then all other engines of
their time.  I know of Drag racers who were able to get over 1400 Horsepower
from the 392 in the late 50's and early 60's so I think they were far from
their limitations.
Don
59 Crown

----- Original Message -----
From: <dardal@xxxxxxxxxxxxxxx>
To: <mailing-list@xxxxxxxxxxxxxxxx>
Sent: Monday, December 23, 2002 10:58 AM
Subject: Re: IML: Why the early Hemis were discontinued (Was The Forward
Look)


> Don, in a way both you and Arron are correct.  Yes, the Hemi has inherent
> volumetric efficiency benefits.  However, the displacement requirements of
the
> industry were increasing, and the Hemi reached its displacement limits at
392
> CID.  That's what Arron is saying.  Even at 392 CID, it already had a
> relatively long stroke, which will reduce somewhat the volumetric
efficiency.
> My guess is that in terms of power per cubic inch, the earlier shorter
stroke
> hemis were superior.  In the Chrysler 300's, the 413's ended up being
faster
> than the 392's.  However, in the Imperial lower state of tune, it appears
that
> the 392's were a bit faster than the wedges, till the 440 appeared much
later.
>
> Here is an added point that Arron just toutched.  The main reason that the
Hemi
> was designed and introduced for a non-racing car in the late 40's was the
very
> low octane available back then.  The central plug location of the Hemi (as
> opposed to the side location of a wedge) allows the engine to use a higher
> compression ratio due to its knock resistance.  It turns out that when you
> increase your compression ratio from say 7:1 to 8.5:1 or 9:1 (remember, we
are
> dealing with very low octane numbers here), you get a very serious
efficiency
> imrpovement.  Then, in the late fifties, the octane increased sufficiently
that
> any wedge could run with 10:1 compression ratio.  It turns out that
increasing
> the compression further (say 12:1) does not give as much of an
incrememntal
> advantage in efficiency and can reduce durability, so it made no sense for
a
> non-racing engine (a racing engine is a different story:  there, even 2
extra
> horsepower can win you the race, and durability is no concern).  So, the
main
> advantage of the Hemi for a non-racing car became obsolete.
>
> D^2
>
> Quoting Don Nonnweiler <dnonnwei@xxxxxxxxx>:
>
> > Arron
> > I disagree that they were an outdated engine as they were used in racing
> >> on and by because they needed a lowline engine for the plymouth and
> > lessor
> > Crysler cars,but it didn't take long to find out they were inferior to
> > the
> > wedge in the breathing dept.  By the way the wedge was out in all
> > 59 Crown
> > ----- Original Message -----
> > From: "A. Foster" <monkeypuzzle1@xxxxxxx>
> > To: <mailing-list@xxxxxxxxxxxxxxxx>
> > Sent: Monday, December 23, 2002 12:10 AM
> > Subject: IML: Why the early Hemis were discontinued (Was The Forward
> > Look)
> >
> >
> > > Don;
>
>
> > >  No one wants to hear this but by the time Chrysler discontinued
> > making
> > the
> > > early hemis they were an outdated engine anyway. This is not to say
> > that
> > the
> > > Hemispherical concept was outdated, many engines before, during, and
> > since
> > > were built with Hemi heads, just that the Chrysler design was. By the
> > time
> > > the RB wedge engines replaced the hemis in 1959, actually in 1958 on
> > DeSotos
> > > and Dodges, the hemis had been bored and stroked to their practical
> > limit.
> > > In order to go any further in displacement with any of the early
> > Hemis
> > they
> >
>
>