426 Max Wedge Engine Compression Ratios

The 426 Maximum Performance Wedge Engine (nicknamed Max Wedge) was produced in 1963 and 1964. Three different compression ratios were used.

The 426 Max Wedge engine has the following compression ratios from the factory:

  • 11.0:1 Compression Ratio (1963-1964)
  • 13.5:1 Compression Ratio (1963)
  • 12.5:1 Compression Ratio (1964)
Year426 Max Wedge Compression Ratio (Dodge)426 Max Wedge Compression Ratio (Plymouth)
1963Ramcharger 426/Ramcharger 426 ll
11.0:1 or 13.5:1 Compression Ratios
Super Stock 426/Super Stock 426 ll
11.0:1 or 13.5:1 Compression Ratios
1964Ramcharger 426 lll
11.0:1 or 12.5:1 Compression Ratios
Super Stock 426 lll
11.0:1 or 12.5:1 Compression Ratios
426 Max Wedge engine compression ratios – Plymouth and Dodge

Plymouth and Dodge had different names for the Max Wedge engines. Plymouth called it Super Stock 426 and Dodge called it Ramcharger 426.

Except for their labels, both versions were the same engine with the same compression ratios and specifications.

Super stock 426 max wedge engine.
Super Stock 426 Max Wedge engine

426 Max Wedge Compression Ratios

The standard compression ratio was the 11.0:1 and the 13.5:1 or 12.5:1 ratios were optional.

The higher compression ratio produced more horsepower and torque. It increased both power ratings by ten each.

For all three ratios, the Chrysler engineers recommended a high-octane gasoline which wasn’t available in the corner gas stations. The main purpose of the engine was for racing and not for street use.

Ramcharger 426 Max Wedge engine.
Ramcharger 426 Max Wedge engine

If you have any questions about the 426 Max Wedge, send us an email found specifically on our contact page.

My first experience with Mopar engines, including the 426 Max Wedge, was 38 years ago. It was when I assembled my first Mopar engine.

Kevin Garce video about the 426 Max Wedge engine.

More Max Wedge Engine Articles

426 Max Wedge Camshaft Specifications

426 Max Wedge Horsepower and Torque

Article Resources

  • Dodge and Plymouth Engine Service Manuals
  • Chrysler Service Bulletins (1962-1964)
  • Dodge and Plymouth Data Books (1962-1964)
  • Google Books: Chrysler Engines 1922-1998

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