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The new 6.4L engine - more details plus specs!
The 6.4L HEMI engine is a bored and stroked version of the 2009 5.7L HEMI engine developed for SRT high performance vehicles.
Compiled by RS For ChallengerTalk.com 11/19/2010
The 6.4L VVT HEMI (392 CID) eight-cylinder SRT high performance engine is a 90° V-Type, deep skirt, lightweight cast iron block with aluminum heads, single cam, overhead valves, and hydraulic roller lifters.
This engine shares the same architecture as the 2009 5.7L HEMI with the following Performance Upgrades:
Increased Bore (103.9 mm (4.09 in.)
Increased Stoke (94.6 mm (3.72 in.)
Increased Valve Sizing
The 6.4L HEMI engine also has improved horsepower, torque and fuel economy as compared with the 6.1L HEMI engine. This is achieved with the larger displacement and the following Technical Improvements:
Variable Cam Timing (VCT) Cam Phasing System
Multi-Displacement System (MDS) (auto trans only)
High Flow Ports
Increased Maximum RPM
Combustion Chamber Shape
Higher Compression Ratio (10.9:1)
The 6.4L engine is equipped with Variable Valve Timing (VVT). This system uses an Oil Control Valve (OCV) to direct oil pressure to the camshaft phaser assembly. The camshaft phaser assembly advances and/or retards camshaft timing to improve engine performance, mid-range torque, idle quality, fuel economy and reduce emissions. The OCV is located under the intake manifold.
The heads incorporate splayed valves with a hemispherical style combustion chamber and dual spark plugs.
The engine oil cooler is engineered for maximum cooling efficiency with no restriction in oil flow. The oil cooler is a stack plate design coolant-to-oil heat exchanger. The oil cooler is mounted between the oil filter and the engine block. The oil cooler uses the radiator coolant system; coolant is circulated through two coolant hoses to maintain a consistent engine oil temperature.
The intake manifold is made of a composite material and features a dual shaft Short Runner Valve (SRV) system to maximize both low end torque and peak power. The SRV is bolted to the rear of the intake manifold and can be service separately from the manifold. The manifold uses a single plane sealing system with individual port seals and a separate PCV port seal to prevent leaks.
The exhaust manifolds are tube in shell air gap design to maximize durability and performance. The exhaust manifolds are made of stainless steel stamped shells and stainless steel tubes with a powdered metal outlet. A layered graphite over perforated steel manifold gasket is used to provide sealing to the cylinder head.
The valve guide seals are made of rubber and incorporate an integral steel valve spring seat. The integral garter spring maintains consistent lubrication control to the valve stems. The intake valve stem seal has a smaller valve spring seat compared to the exhaust valve stem seal. The intake and exhaust valve stem seals are identified by different colors.
The pistons are made of a high-strength aluminum alloy. Piston skirts are coated with a solid lubricant (Molykote) to reduce friction and provide scuff resistance. The piston top ring groove and land is anodized. The connecting rods are made of forged powdered metal with a “fractured cap” design. A floating piston pin is used to attach the piston and connecting rod.
Four dual-nozzle oil jets are bolted to the cylinder block underneath the main oil gallery. The jets connect with an oil-tight fit to the main gallery through lubrication passages. Each oil jet helps cool the two opposing pistons.
The cylinders are numbered from front to rear; 1, 3, 5, 7 on the left bank and 2, 4, 6, 8 on the right bank.
The firing order is 1-8-4-3-6-5-7-2.
MDS (auto transmission models only)
The Multiple Displacement System (MDS) provides cylinder deactivation during steady-speed, low-acceleration and shallow grade climbing conditions to increase fuel economy.
MDS can provide a 5-20% fuel economy benefit when operating in four-cylinder mode depending on driving habits and vehicle usage. For EPA rating purposes the fuel economy is 8-15% higher than if the engine was operating on eight cylinders at all times.
MDS is integrated into the basic engine architecture requiring these additional parts:
Unique MDS camshaft
8 deactivating roller lifters
4 control valve solenoids
Control valve solenoid wiring harness
Oil temperature sensor
6.4L Spec sheet attached (PDF)