Story and photo by Steve Magnante, www.moparmax.com - used by permission
Also see our main Max Wedge page
These are great times for Max Wedge fans. Never before have so many
cross ram choices been available for your consideration. We’re not
talking about obscure swap meet oddities either, we’re talking about
foundry fresh castings you can easily buy right now.
While aftermarket sources such as Indy Cylinder Head offer loose
interpretations of the cross ram for all out drag racing, this review
is limited to those manifolds that seek to retain the original
appearance. Half of the treat of lifting the hood on a Max Wedge is having the right look.
Before we start this review, let’s remember the hows and whys of ram
tuning. In a nutshell, as each cylinder
pulls fuel and air during the intake stroke, the column of
fast-moving gasses has a certain amount of mass. As the piston
approaches bottom dead center, the intake valve closes and the column
of gasses comes to a sudden stop inside the intake tube, creating energy in the form of pressure waves that
bounce back and forth between the back of the closed intake valve
and the mouth of the carburetor, at something like 1,100 feet per
The next time the intake valve opens, there
should be a pent-up wall of gasses waiting to crash the gate and fill
the cylinder bore — if you tailor the valve timing just so, and if you
configure the intake runner in just the right way. This provides a form
of free supercharging.
It isn’t like plopping a belt driven GMC 6-71
on top of things, but it’s a proven fact that induction efficiency of
as much as 108% — that’s 8% above atmospheric - can be
realized. If that isn’t free supercharging, we don’t know what is.
By adjusting the length and volume of the intake
runners, you can tune the incoming supercharged rush to occur at
specific engine speeds, thus boosting cylinder pressure and torque in
harmony with the selected rpm point.
Back in 1960, when Chrysler unleashed the two piece long-ram induction
systems on full size cars, the goal was improved low and mid
range torque for quick stop light getaways and rapid highway passing.
The runner length was 30-inches and the resulting
torque spike occurred from 2800 rpm through about 4800
rpm. It was great for moving two-plus tons of luxury liner, but the
long branches choked flow after 5000 rpm so the top end performance
But when Chrysler got serious about entering the Super Stock fray in
1962, they knew top end breathing was more important than
passing power on the highway, so they reduced the runner length to
15 inches, tuning the resulting one piece cast aluminum
manifold for 5400 rpm. The Max Wedge was born.
The original cross ram is very well suited to a 413
cubic inch engine spinning at 6500 rpm. When they upped displacement
to 426 in 1963 and 1964 to take full advantage of the 7 liter cap
imposed by NASCAR, the manifold still worked well. But as racers got
creative and started using 488-cube stroker cranks and stepping up the
cam and valve springs for 7000 rpm rev capability, the cross ram
quickly got in the way and choked power.
With the 426 Race Hemi due on the scene for 1964, factory Max Wedge
development ground to a halt. Word is that Barney Navarro — perhaps with assistance from
Chrysler - cast some wild cross ram intake manifolds with four Carter
AFB caburetors in place of the usual two. Max Wedge guru Bob Mazzolini
supposedly has one of these crazy quad quad Maxie manifolds. But Hemi
fever was on and after mid-1964, the Max Wedge pretty much slipped
into obscurity for the next four decades, a swap meet relic.
In recent decades, more and more people are rediscovering the Max
Wedge and want to tap into the mystique of the Orange Monster.
Simply put, if you are doing a Max Wedge clone, you simply must get a
cross ram. There is no place for single quads — even though many are
capable of outperforming the mighty Max Wedge, all other things
being equal. Sometimes looks are more important than raw performance.
Original story and additional photos: http://www.moparmax.com/features/2008/iii_2-wedge-1.html
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