(Image/Stellantis)

When Chrysler announced it was bringing back the legendary Hemi in the early 2000s, it was a big deal. This new series of Hemi engines is often referred to as the “Gen. 3” after the first generation FirePower (1951-59) and second generation Elephant 426 (1964-71).

Note: This Spec Guide is part of a series of Hemi Engine Spec guides we’re putting together. See Other Hemi Engine Spec Guides Here.

Bigger is Better: Meet the 6.4L Gen. III Hemi Apache

This engine plays off of a historical aspect of one of the early Gen. I Hemi 392 cubic inch engines introduced in 1957. Developed under code name “Apache,” this Gen. III version first appeared in 2011 and offers increased displacement and power over the previous 6.1L Hemi with a longer stroke. This engine also carries the BGE casting mark on the block that stands for Big Gas Engine that is used in a number of different vehicles, from the Dodge Challenger to medium duty Ram trucks.

The larger truck 6.4L engines use a lower 10.0:1 compression compared to the passenger cars and SUVs that sport 10.9:1 compression, and this higher squeeze helps make as much as 485 hp and 475 lb.-ft. of torque. That’s outstanding horsepower for a normally aspirated production engine that will make serious power well past 150,000 miles (and be fully emissions compatible).

This Guide is for the 2011+ Mopar Gen. III 6.4L Apache Hemi

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2011+ Mopar Gen. III 6.4L Apache Hemi Performance & Applications

YearModelHorsepowerTorque
(ft.-lbs.)
2011-14Challenger SRT8460 @ 6,000 RPM470 @ 4,200 RPM
2015Challenger SRT8485 @ 6,100 RPM475 @ 4,700 RPM
2015Cherokee/Durango475 @ 6,000 RPM470 @ 4,300 RPM
2014+Ram 2500/3500366 - 410 @ 5,600 RPM429 @ 4,000 RPM

2011+ Mopar Gen. III 6.4L Apache Hemi Engine Compression

VersionCarSUVRam Truck
Compression10.9:110.9:110.0:1

2011+ Mopar Gen. III 6.4L Hemi Engine Block Specs

Mopar 6.4L Hemi Block Specs
Casting Numbers5037473BE (or)
5037473BG “6.4L”
MaterialIron
Displacement6.4L / 391 c.i.d.
Bore Dia.4.090"
Stroke3.72"
Deck Height9.25"
Bore Spacing4.46"
Thrust Bearing LocationNumber 3
Main Cap Style2 Bolts with Lateral Cross-Bolts
Cam-to-Crank Centerline7.44"
Bellhousing Bolt Pattern Same as Earlier Magnum LA V8 Small Block, but with Top Center Bolt Eliminated
Piston Squirters Yes

2011+ Mopar Gen. III 6.4L Hemi Engine Rotating Assembly

Mopar 6.4L Hemi Engine Rotating Assembly Specs
Piston MaterialHypereutectic
Piston StyleSlight Dome with Valve Notches
(Truck is different)
Piston Ring Package1.2mm, 1.2mm, 2.0mm
Wrist Pin Diameter0.945"
Connecting Rod MaterialPowdered Metal
(Improved strength design)
Connecting Rod StyleI-Beam
Connecting Rod Length6.200"
(Shorter than other Gen. III Hemis)
Connecting Rod Bearing Bore2.125"
Crankshaft MaterialForged Steel
Crankshaft Main Journal Dia.2.559"
Crankshaft Rod Journal Dia.2.126"
Crankshaft Reluctor Count58x
Crankshaft Mounting Flange8 Bolts

2011+ Mopar Gen. III 6.4L Hemi Engine Cylinder Heads

Mopar 6.4L Hemi Engine Cylinder Head Specs
Casting NumberCar/SUV
5037369BD (or)
68166435AA-A02
Truck
05045468AE (and)
68166435AA, AB, AC, AD
Cylinder Head Material356 T6 Aluminum
Combustion Chamber74cc
Intake Port ShapeSquare
Exhaust Port Shape"D" Shaped
Intake Valve Diameter2.14"
Intake Valve DesignHollow Stem
Exhaust Valve Diameter1.65"
Exhaust Valve DesignHollow Stem, Sodium Filled
Cylinder Head Bolt StyleTorque to Yield (TTY)
Cylinder Head Bolt SizeM12 x 1.5mm & 8mm
Spark Plug14mm, Gasket, 1.043" Reach, Projected Nose, 5/8" hex

2011+ Mopar Gen. III 6.4L Hemi Apache Engine Cam Specs

Mopar 6.4L Hemi Engine Camshaft Specs
Duration @ 0.050" (Intake/Exhaust)221° / 225°
Lobe Separation Angle114°
Valve Lift
(Intake/Exhaust)		0.571" / 0.536"
Multiple Displacement System (MDS)?Only In Vehicles w/Automatic Transmission
Variable Cam Timing (VCT)?Yes
Cam Journal Dia.57mm Front
(Note: Smaller to the rear.)

2011+ Mopar Gen. III 6.4L Hemi Engine Valvetrain Specs

Mopar 6.4L Hemi Valvetrain Specs
Lifter DesignHydraulic
Lifter RetainerPlastic Holder
Lifter Body Diameter0.842"
Rocker Arm Mounting StyleShaft
Rocker Arm StyleDie Cast, Roller Fulcrum
Rocker Ratio1.60:1 (Intake)
1.66:1 (Exhaust)
Valve Spring StyleBeehive
Valve Angle18° (Intake)
16.5° (Exhaust)
Timing Chain Guide StyleSpring-Loaded Tensioner

Other Key 2011+ Gen. III 6.4L Hemi Engine Specs

6.4L Hemi Throttle Body, Fuel Injectors, Oil Pan & More
Intake ManifoldComposite
“Active” with variable length
Throttle Body80mm, 4-Bolt
Throttle ControlElectronic
Fuel Injector FlowCar/SUV
27 lb./hr. @ 58 PSI
MD/HD Truck
31 lb./hr. @ 58 PSI
Flex Fuel CapableNo
Fuel Injector ConnectorUSCAR, EV6
PCM GPEC2 (or)
GPEC2A
Crankshaft Reluctor Ring58x
Camshaft Sensor LocationPassenger Side, Front
Oil PumpGerotor
Variable Cam Timing (VVT)Yes
Firing Order1-8-4-3-6-5-7-2
Total Weight, Full Dress582 lbs.
Keywords
392, 6.4L, Chrysler, Dodge, Engine Specs, Gen III HEMI, HEMI, Hemi Spec Guide, Jeep, Mopar
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Author: Jeff Smith

Jeff Smith has had a passion for cars since he began working at his grandfather's gas station at the age 10. After graduating from Iowa State University with a journalism degree in 1978, he combined his two passions: cars and writing. Smith began writing for Car Craft magazine in 1979 and became editor in 1984. In 1987, he assumed the role of editor for Hot Rod magazine before returning to his first love of writing technical stories. Since 2003, Jeff has held various positions at Car Craft (including editor), has written books on small block Chevy performance, and even cultivated an impressive collection of 1965 and 1966 Chevelles. Now he serves as a regular contributor to OnAllCylinders.