413 Max Wedge Engine Compression Ratios
There were two different compression ratios for the 413 Maximum Performance Wedge (nicknamed Max Wedge) engine produced in 1962.
The 413 Max Wedge engine has the following two compression ratios:
- 11.0:1 Compression Ratio
- 13.5:1 Compression Ratio
| Year | 413 Max Wedge (Dodge) | 413 Max Wedge (Plymouth) |
| 1962 | Ramcharger 413 11.0:1 or 13.5:1 Compression Ratios | Super Stock 413 11.0:1 or 13.5:1 Compression Ratios |
Dodge called their Max Wedge the Ramcharger 413. Plymouth called their Max Wedge Super Stock 413.
Both versions, except for their labeling, were the same engine and had the same compression ratios and specifications.
413 Max Wedge Engine Compression Ratios
The 11.0:1 compression ratio came standard. The higher ratio of 13.5:1 was available as an option.
The higher compression ratio produced more power. The 13.5:1 ratio increased horsepower and torque by ten each.
Chrysler engineers recommended a higher octane due to the high compression ratios.
Compression Ratio Specifications
The combustion chamber volume is a minimum of 83 c.c. to a maximum of 86 c.c.
To reduce the volume of the combustion chamber 1 c.c., .005″ must be milled from the head surface. The cylinder head surface finish should be 100-120 micro-inches.
For each 0.010″ removed from the cylinder head 0.012″must be removed from the intake side of the head.
Distance from the top of the lower flat of piston to the block deck:
Compression ratio 11.0:1
- Minumum .0155
- Maximum .0455
Compression ratio 13.5:1
- Minumum .018
- Maximum .043
Read more Mopar compression ratio articles:
If you have any questions about the 413 Max Wedge, send us an email found specifically on our contact page.
My first experience with Mopar engines, including the Max Wedges, was 38 years ago. It was when I assembled my first Mopar engine.
Read More Max Wedge Engine Articles
413 Max Wedge Horsepower and Torque
413 Max Wedge Cylinder Head Specs
Article Resources
- Google Books: Chrysler Engines 1922-1998
- Dodge and Plymouth Data Books
- Dodge and Plymouth Bulletins
- Dodge and Plymouth Service Manuals
- Wikipedia: Max Wedge
