6820-4075 6.1 Small Block Mopar Hemi Gen III FX Series -1.5cc Flat Top Gen III Hemi Forged Piston Set 4.075 inch bore COMP HEIGHT: 1.21"
6820-4075 6.1 Small Block Mopar Hemi Gen III FX Series -1.5cc Flat Top Gen III Hemi Forged Piston Set 4.075 inch bore COMP HEIGHT: 1.21"
6820-4075 6.1 Small Block Mopar Hemi Gen III FX Series -1.5cc Flat Top Gen III Hemi Forged Piston Set 4.075 inch bore COMP HEIGHT: 1.21"
6820-4075 6.1 Small Block Mopar Hemi Gen III FX Series -1.5cc Flat Top Gen III Hemi Forged Piston Set 4.075 inch bore COMP HEIGHT: 1.21"
6820-4075 6.1 Small Block Mopar Hemi Gen III FX Series -1.5cc Flat Top Gen III Hemi Forged Piston Set 4.075 inch bore COMP HEIGHT: 1.21"
6820-4075 6.1 Small Block Mopar Hemi Gen III FX Series -1.5cc Flat Top Gen III Hemi Forged Piston Set 4.075 inch bore COMP HEIGHT: 1.21"
6820-4075 6.1 Small Block Mopar Hemi Gen III FX Series -1.5cc Flat Top Gen III Hemi Forged Piston Set 4.075 inch bore COMP HEIGHT: 1.21"
6820-4075 6.1 Small Block Mopar Hemi Gen III FX Series -1.5cc Flat Top Gen III Hemi Forged Piston Set 4.075 inch bore COMP HEIGHT: 1.21"
Load image into Gallery viewer, 6820-4075 6.1 Small Block Mopar Hemi Gen III FX Series -1.5cc Flat Top Gen III Hemi Forged Piston Set 4.075 inch bore COMP HEIGHT: 1.21"
Load image into Gallery viewer, 6820-4075 6.1 Small Block Mopar Hemi Gen III FX Series -1.5cc Flat Top Gen III Hemi Forged Piston Set 4.075 inch bore COMP HEIGHT: 1.21"
Load image into Gallery viewer, 6820-4075 6.1 Small Block Mopar Hemi Gen III FX Series -1.5cc Flat Top Gen III Hemi Forged Piston Set 4.075 inch bore COMP HEIGHT: 1.21"
Load image into Gallery viewer, 6820-4075 6.1 Small Block Mopar Hemi Gen III FX Series -1.5cc Flat Top Gen III Hemi Forged Piston Set 4.075 inch bore COMP HEIGHT: 1.21"
Load image into Gallery viewer, 6820-4075 6.1 Small Block Mopar Hemi Gen III FX Series -1.5cc Flat Top Gen III Hemi Forged Piston Set 4.075 inch bore COMP HEIGHT: 1.21"
Load image into Gallery viewer, 6820-4075 6.1 Small Block Mopar Hemi Gen III FX Series -1.5cc Flat Top Gen III Hemi Forged Piston Set 4.075 inch bore COMP HEIGHT: 1.21"
Load image into Gallery viewer, 6820-4075 6.1 Small Block Mopar Hemi Gen III FX Series -1.5cc Flat Top Gen III Hemi Forged Piston Set 4.075 inch bore COMP HEIGHT: 1.21"
Load image into Gallery viewer, 6820-4075 6.1 Small Block Mopar Hemi Gen III FX Series -1.5cc Flat Top Gen III Hemi Forged Piston Set 4.075 inch bore COMP HEIGHT: 1.21"

PART #: 1-6820-4075

6820-4075 6.1 Small Block Mopar Hemi Gen III FX Series -1.5cc Flat Top Gen III Hemi Forged Piston Set 4.075 inch bore Pin Dia.: 0.984" Comp Height: 1.21"

$669.95
$669.95
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Piston Series Option:
Piston Ring Kit Option:
Ships in 1 - 8 days

Ships in 1 - 8 days

Made in the USA

Made in the USA

Secure Payment

Secure Payment

This is a pre order item. We will ship it when it comes in stock.

373 Small Block Mopar Hemi Gen III, FX, Comp Height: 1.21, -1.5cc Flat Top , PIN: .984", Full-Floating or Press Fit, Ring Groove: 1.2/1.2/3MM, Stroke: 3.578", ROD: 6.243, Approx Comp Ratio: 65cc-11.11, 74cc-10.04, 85cc-9


Piston Top Aprox. Comp. Ratio:

-1.5cc Flat Top Gen III Hemi
ChamberComp Ratio
6511.11 to 1
7410.04 to 1
859 to 1

For accurate Comp Ratio info use the calculator below.

Engine Brand: Mopar

Engine Family: Small Block Mopar Hemi Gen III

Engine Size: 6.1

Cylinder Bore Size: 4.075 in , 103.424 mm

Ring Groove Width: 1.2/1.2/3MM

Compression Height: 1.210"

Pin Diameter: 0.984"

Connecting Rod Length: 6.243"

Crankshaft Stroke: 3.578"

Cylinder Head: Gen III Hemi

TDC Assembly Height: 9.242" ( Zero Deck Height )

Download Piston Instructions

 
Features: Piston Series
 

E series

  SX series  1-FX series  2-FX series  3-FX series
Broached pin oiling slots

x

x

 

 

 
Drilled, forced wrist pin oiling

 

x

x

x

x
Forged drain-back windows

x

 

 

 

 
Drilled bottom ring land intersecting oil groove drain-backs

 

x

x

x

x
Slightly larger, deeper valve reliefs than OEM

x

 

 

 

 
CNC machined valve reliefs for moderate performance heads and cam combinations

 

x
Larger, deeper CNC valve reliefs for more aggressive cylinder head and cam combinations

 

 

x

x

x
Premium Aircraft spec. 4032 low expansion alloy

x

x

x

 

 
Premium Aircraft spec. 2618 alloy

 

 

 

x

x
Blower, Turbo, NOS ready

 

x

x

x

x
Brushed piston crown

 

 

x

x

x
Turned dishs

x

x

 

 

 
Max Quench milled dishs

 

 

x

x

x
Additional CNC milling for weight reduction in non-critical areas

 

 

x

x

x
Patented “X Groove” skirt for superior cylinder and ring life

 

 

x

x

x
Thinner/shallower Ring grooves for maximum ring seal and land strength

 

 

x

x

x
Low volume contact reduction grooves    

x

x

x
2nd ring land accumulator groove prevents ring flutter    

x

x

x
3rd ring land scraper relief    

x

x

x
Oil ring groove relief reservoir    

x

x

x
Inner and outer pin boss weight reduction radiusing    

x

x

x
Tighter control of crown thickness yields consistently lighter parts    

x

x

x
Dynamic skirt milling controls skirt thickness for consistently lighter parts  

 

x

x

x
Diamond-turned high strength skirts

x

x

x

x

x
High-strength piston pins

x

x

x

x

x
Extreme Duty XR wrist pins      

 

x
Horizontal Gas Ports enhance ring seal        

x
Forged and machined in the USA

x

x

x

x

x
Piston Specs

Piston Top Aprox. Comp. Ratio:

-1.5cc Flat Top Gen III Hemi
ChamberComp Ratio
6511.11 to 1
7410.04 to 1
859 to 1

For accurate Comp Ratio info use the calculator below.

Engine Brand: Mopar

Engine Family: Small Block Mopar Hemi Gen III

Engine Size: 6.1

Cylinder Bore Size: 4.075 in , 103.424 mm

Ring Groove Width: 1.2/1.2/3MM

Compression Height: 1.210"

Pin Diameter: 0.984"

Connecting Rod Length: 6.243"

Crankshaft Stroke: 3.578"

Cylinder Head: Gen III Hemi

TDC Assembly Height: 9.242" ( Zero Deck Height )

Download Piston Instructions

Piston Series Comparison Chart
 
Features: Piston Series
 

E series

  SX series  1-FX series  2-FX series  3-FX series
Broached pin oiling slots

x

x

 

 

 
Drilled, forced wrist pin oiling

 

x

x

x

x
Forged drain-back windows

x

 

 

 

 
Drilled bottom ring land intersecting oil groove drain-backs

 

x

x

x

x
Slightly larger, deeper valve reliefs than OEM

x

 

 

 

 
CNC machined valve reliefs for moderate performance heads and cam combinations

 

x
Larger, deeper CNC valve reliefs for more aggressive cylinder head and cam combinations

 

 

x

x

x
Premium Aircraft spec. 4032 low expansion alloy

x

x

x

 

 
Premium Aircraft spec. 2618 alloy

 

 

 

x

x
Blower, Turbo, NOS ready

 

x

x

x

x
Brushed piston crown

 

 

x

x

x
Turned dishs

x

x

 

 

 
Max Quench milled dishs

 

 

x

x

x
Additional CNC milling for weight reduction in non-critical areas

 

 

x

x

x
Patented “X Groove” skirt for superior cylinder and ring life

 

 

x

x

x
Thinner/shallower Ring grooves for maximum ring seal and land strength

 

 

x

x

x
Low volume contact reduction grooves    

x

x

x
2nd ring land accumulator groove prevents ring flutter    

x

x

x
3rd ring land scraper relief    

x

x

x
Oil ring groove relief reservoir    

x

x

x
Inner and outer pin boss weight reduction radiusing    

x

x

x
Tighter control of crown thickness yields consistently lighter parts    

x

x

x
Dynamic skirt milling controls skirt thickness for consistently lighter parts  

 

x

x

x
Diamond-turned high strength skirts

x

x

x

x

x
High-strength piston pins

x

x

x

x

x
Extreme Duty XR wrist pins      

 

x
Horizontal Gas Ports enhance ring seal        

x
Forged and machined in the USA

x

x

x

x

x
Engine Power TV

The DSS FX, X-Groove Feature