The brief History of MoPar Hemi's and Big Block Wedges

From: Steven T. Ekstrand (cyberlaw@earthlink.net)
Date: Sat Jul 08 2000 - 20:18:01 EDT


Thanks LJ for posting those engine charts regarding the old Hemi's.

About the most common ones I see here and there cheap are the 331
Chryslers. I don't know the production numbers. The ultimate Top Fuel
motor in the OLD days was the 392.

At the Hot Rod shows you'll see lots of Early Hemi's (usually 331, 354, or
392 Chryslers). They aren't that expensive and they aren't necessarily the
ultimate in power, but boy do they look hot!

The wedge head B motors (low deck 3.38" stroke big blocks like the 350,
361, 383, and 400) replaced the early hemi's in 1958. The early 350 and
361 didn't do much to inspire the performance crowd and hot rodders
scrounged the junkyards for 392's. Soon though the B's were given a raised
deck for a longer 3.75" stroke and the 413 was born (new RB block
designation). This engine was far lighter and had better output than the
old Early Style Hemi's.

It would get better!

A special High Flow head was developed for use on the 413 and called the
Max Wedge head. THIS HAD NOTHING AT ALL TO DO WITH THE HEMIs, EARLY or
NEW, RACE or STREET. Do not get them confused as somebody did (not LJ as
he obviously knows his Hemi's well!). This had nothing to do with
semantics or marketing idiots. These are different engines.

In 63, the 413 Max Wedge got a displacement increase to 426 which causes
much of the confusion. The 426W is NOT a 426 Hemi. There were two
versions of the 426 Max Wedge. The Stage I and the Stage II. They were
awesome. One of the most popular current drag setups is to use the Max
Wedge style heads and Manifold on a later 440 or even a stroked 440.
Visually, a Max Wedge was distiguishable from its pedestrian brethren by
the wild induction setups that took advantage of the massive intake ports
and large valves. Also Cast Iron Exhaust Headers that looked like a George
Barris creation.

The Max Wedges dominated the street scene and the track in 62 and 63, but
the competition was closing in. In 1963, Chrysler began experimenting with
a new Hemi head similar to the design of the early Hemi head but adapted to
the larger displacement, lighter RB block. For strength the block was
highly modified so although based on an RB block the Hemi block is
different and not interchangeable with an RB block (there was a company
that later adapted a special Hemi head casting to a standard B or RB block
creating a cheap street hemi for hot rodders back when the Hemi blocks
weren't being produced).

This 63 prototype saw its way into the hands of the occasional drag racer
and in February of 1964 dropped the hammer on the Daytona 500. The 426
Race Hemi was born! You couldn't confuse this Hemi with a wedge motor!
Massive valve covers with the spark plugs deep in tubes plunged right
through the center of the heads. The later Hemi (Elephant motor) had a
taller deck and the distributor angled in the front of the motor when
compared visually with an Early style Hemi (Whale motor).

In 1965, the 12.5 to 1 compression Race Hemi was the key ingrediant to the
Lightweight Super Stock drag cars that dominated NHRA racing and later led
to the AFX cars and then split to form Pro Stock on one branch of the tree
and Funny Car on the other.

In 1966, the new Hemi truly made the street. Upon til now the Hemi was
truly a race only motor. Built by the factory in the minimum number to
qualify for competiton. The 66 Street hemi was detuned with 10.5 to 1
compression and less carbueration. The Street Hemi would continue until
1971. In 1968, a few hundred Race Hemis were produced for use in the Hurst
built S/S Barracuda's and S/S Dart's that still dominate NHRA SS/A and
SS/AA running high 8's in class legal trim!

In 1969 1/2, the RB engine that had largely been overshadowed by the
awesome Hemi got one last hoorah. The 440-6 engine used the big bore
version of the RB introduced into the passenger car line up in 1966. The
key to the package was an Edelbrock aluminum manifold and three Holley two
barrel's (effectively three halfs of a Holley 4160). The center carb acted
as the primaries with the outboard carbs coming in when the calvary
charged. The Six Pack's (Dodge) and the Six Barrel's (Plymouth) may have
possibly been the ultimate true street motor of alltime. They were used in
production Road Runners, Super Bee's, Challenger R/T's, Cuda's, Daytona
Chargers, and Superbird's as an alternative to the expensive Street Hemi's.
In 1970, they lost the Edelbrock manifold to a factory cast iron unit.

I'm biased, but I've always felt the 440-6 was a better and faster street
engine than the Street Hemi, but it depends on the application. Nothing
screams at the top end like a 426 Hemi! And nothing screams like a Hemi
when you open the hood!

Still my Six Barrel Road Runner is capable of turning a few heads.

This doesn't solve the debate of what is technically a Hemi vs a canted
valve vs a poly head design, but it does give a good start to understanding
some of the pedigree we all share in Mopardom!

Steve Ekstrand, Pasadena, CA Driver: '00 Dakota CC SLT+ 4.7L 3.92SG 255's
Stacey's Driver: '00 Inferno Red Intrepid ES-3.2L-24V Autostick w/Leather
Race Car: 69 1/2 Road Runner 440-6 (NHRA SS/GA future B/SA???)
Project Car: 69 Barracuda Notchback (Weekend Driver/AutoXr/Beast)
Homepage: http://sites.netscape.net/professormopar/homepage



This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 11:52:34 EDT