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Max Wedge: Maximum Output

by Steve Boelhouwer

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During the 1960s, more innovative engine ideas flowed out of Chrysler than from any other auto manufacturer. Though many of the engines produced in the late 1950s laid the groundwork for what was to come, the Max Wedge, launched in 1962, propelled Mopar racers to the forefront, where they would stay until the demise of the muscle car era.

A Historical Perspective

In June of 1957 the AMA (Automobile Manufacturing Association), fearing a government and public outcry over safety issues, passed a ban on all factory-sponsored racing activities. Compliance with this ban did not last long [and did not prevent automakers from adding power to their engines]. In 1960, Ford was the first to defy the order, by producing the "Special Power" 352 CID engine. Chevrolet and Pontiac also jumped into the fray with 409s and "Tri-power" carb setups. This not only garnered attention on the racetrack, but also generated a lot of "image" and subsequent sales at the dealerships. Mopar had no such "image" product at the time. As Chrysler's Dick Maxwell stated in a 1984 interview, "We were virtually invisible on the street." However, these packages were not strictly engineered for racing, and often lost to more "pedestrian" Mopar 383s on both the track and the street.

Factory involvement with drag racing actually had some deeper roots at Chrysler. In the 50s some young engineers, most notably Maxwell, Jim Thornton and Tom Hoover, formed the RamChargers racing team. Working with limited resources, they left an impressive mark on drag racing during this era, and laid the groundwork for what was to come.

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Birth of the Max Wedge

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As mentioned earlier, the prime mover of Mopar performance in the early 60s was the 383. In 1960, Chrysler introduced the wild aluminum cross-ram intake setups for the motor, which suspended the carbs over the fenders and fed the air/fuel mixture through long two runners which ran over the valve covers on opposite sides of the engine (photo at right). A nasty short-ram setup was also available but only through the parts department. The cross-rams helped Mopar win a combined nine races on the Grand National (NASCAR) circuit that year. The 413 was also on the streets during that era, and was one of the few engines (the Hemi being the other) that could truly be considered as being designed specifically for racing. It was also available with the cross-ram setup and produced a maximum 375 hp. While both of these engines could be classified as high-performance street engines, the engineers were busy designing a motor designed strictly for drag and oval-track racing.

NEW! 413 dyno tests conducted at Chrysler in 1959

This work resulted in the 1962 introduction of the Max Wedge 413, which came equipped with not only a cross-ram setup (this time a short one with the carburetors mounted conventionally between the valve covers), but also a pair of huge, upswept cast iron exhaust manifolds. These are probably the most exotic-looking factory race parts ever made in the United States. Pistons were available in two compression ratios: 11:1 and 13.5:1. Mechanical cams and lifters were used . The heads were a new design with huge (2.08" intake) valves ground to a tulip shape. There were many other special parts used as well, including beefed-up valve gear and oiling components. Also, the factory made sure to upgrade the transmissions bolted behind these motors.

These parts made the 413 Max Wedge cars all but unusable on the street, but on the track the results were immediate. The 1962 NHRA record books show four class records established by the 413. With the correct gearing and tires, mid-twelve-second passes became commonplace.

Further Refinements

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On June 1, 1963 the Max Wedge block grew to 426 cubic inches, thanks to a larger 4.25" bore. These were referred to as the Stage II engines. Again, many special parts were used. In addition, Chrysler began producing special bodies which would complement these engines, using aluminum front ends, trunk-mounted batteries, hood scoops and other lightweight parts. By this time Mopars virtually owned the Super Stock classes in the NHRA, and the introduction of the Stage IIs gave NASCAR racers more top-end power to be competitive. From a technical perspective, the Stage II motors were significant because they opened up the science of cylinder-head air flow engineering. The end result of this science would be the rebirth of the Hemi®.

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The final Max Wedge, the Stage III, was released in 1964. The biggest improvements were a revised cylinder head and new camshaft design. This was the pinnacle of the Max Wedge series. However, in 1964 the Hemi® was re-introduced, and was designed to eventually surpass the Wedge motors in terms of performance. But it was the Wedge motors that gave the Mopar engineers time to perfect multi-carb setups, camshaft designs, valve and port shapes, and bottom-end reliability. And as a monument to the efforts of these engineers, the Max Wedge cars are still competitive in drag racing today.

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This article only scratches the surface in terms of Max Wedge history. For further information, two excellent sources are: Mighty Mopars by Anthony Young (Motorbooks International, 1983) and Volume 11 Number 2 of Performance for the Chrysler Car Enthusiast (RHO publications, 1994).

The Many Flavors of Max Wedge

The Sonoramic Commando Engines

Development of the Cross-Ram Wedge

Go to Allpar or Visit the Mopar Engines Page

B series and RB series V8 engines

Copyright © 1998 Steve Boelhouwer; used by permission

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