Why Are Edelbrock Diesel Cylinder Heads Better for Your 6.6L Chevy Duramax Diesel Engine?
During the development of the new Edelbrock Diesel Cylinder Head for the 6.6L Chevrolet Duramax engine, particular attention was paid to improving the motion of air in the cylinder. This motion of air in relation to the amount of flow is a critical balance to maintain and improve upon in a diesel engine application, perhaps even more so than in a high-performance gasoline engine.
“Port design played a major role in the development of the new Edelbrock Diesel Cylinder Heads for the 6.6L Duramax Diesel engine,” said Edelbrock’s Matt Gamble, the Design Engineer in charge of diesel cylinder head development. “The main objective was to optimize the volumetric flow rate to obtain the highest flow while maintaining adequate motion of the air, or swirl, as it enters the cylinder to make power.”
Edelbrock’s in-house team of cylinder head engineers not only managed to make a head for the 6.6L Duramax with better flow than the factory head but did so with a swirl ratio that is very similar to that of the factory to get a complete and clean burn, two important factors in meeting the government’s stringent diesel emissions requirements. The result is a 50-state emissions-legal, high-performance cylinder head for the 6.6L Duramax. For racing vehicles, it offers increased potential when you want to turn up the boost because it is no longer the restriction in the system. These new Edelbrock Diesel Cylinder Heads are much more capable of flowing air while still providing correct combustion.
As a result of the successful introduction of the new high-performance Duramax Diesel head, Edelbrock enters 2019 with its first-ever product developed especially for the diesel engine market. The all-new Edelbrock Cylinder Heads for 2001-2016 GM 6.6L Duramax Diesel V8 engines are a direct bolt-on replacement for any street or off-road application where higher levels of performance and durability are desired.
“The bulk flow rate or volumetric flow rate is much greater than a factory head, but it still produces efficient combustion, meets CARB requirements, and makes power. There’s a lot more potential if you want to turn up the boost, as the cylinder head is no longer the restriction in the system. These heads are much more capable of flowing air while still providing correct combustion.” — Matt Gamble, Edelbrock Design Engineer
These aluminum heads come complete and ready to run straight out of the box and are designed to fit all four variations of the Duramax engine that were offered in the popular Silverado HD pickup truck as well as Chevy/GMC vans and medium-duty trucks between 2001 and 2016. The heads are compatible with all stock Duramax valvetrain components as well as valve covers, water crossover, injector and glow plugs.
Part Numbers for the New Edelbrock Duramax Cylinder Head:
Like all of the high-performance cylinder heads that carry the Edelbrock name, the new Duramax Diesel heads are cast at the company’s in-house foundry located in Southern California, ensuring that each A356 aluminum casting is properly heat- and pressure-treated to reduce porosity while also increasing both strength and fatigue properties. The heat-treating process for the new Duramax heads is the T7 spec rather than the standard T6.
The T7 specification for heat treating results in castings referred to as “overaged.” The artificial aging step of aluminum heat treating is carried a step further than the industry standard T6. This additional process reduces the residual stress in the casting and results in a more dimensionally accurate finished product. T7 affects the tensile strength, compressive strength, and hardness of the casting, reducing the likelihood of cracks, dropped seats, or lifting heads in extreme operating environments.
Another treatment that each Edelbrock Duramax Diesel head receives during manufacturing is called Hot Isostatic Pressing, or HIP. This is an aerospace process in which raw aluminum castings are heated to 900 degrees Fahrenheit in a pressurized chamber with up to 30,000 PSI. This effectively compresses each casting to eliminate imperfections by removing any trapped gases or internal porosity. The result is an incredibly strong and dense sand casting that has three times the fatigue life and nearly the consistency of billet aluminum. For engine builders and racers, HIP-processed cylinder heads provide less chance of failure due to fatigue. They also provide a better, smoother machined surface finish when CNC port and chamber work is applied.
With intake and exhaust runners optimized for maximum flow and motion, engine builders and head porters will appreciate the extra deck and port wall material on these heads for custom porting and deck strength. Flow rate on the exhaust side of the Edelbrock Duramax heads is excellent compared to the factory. A better-flowing head translates into more energy to drive the turbocharger faster to make more power, or make the same amount of power with less effort.
While achieving maximum efficiency on the intake side was a primary goal, having a good exhaust side of the cylinder head was equally important to lower the restriction through the heads. As restriction decreases in a turbo-diesel cylinder head, the boost goes down and more air goes through, which in turn brings the intake air temperature down. Cooler air is denser so you can get more air in.
Features and Benefits of the new Edelbrock Duramax Diesel Cylinder Head:
- Improved air flow and motion characteristics can deliver an increase in power and torque
- Designed, cast, machined and assembled in the USA
- Injector cups are integrated into the castings for LB7 applications
- Castings are treated to Hot Isostatic Press (HIP) process for strength
- Heat-treated to T7 for the extreme diesel operating environment
- Thick 16mm deck for increased cylinder pressures
- Raised rocker valley adds water volume in head
- All factory components bolt on without modification
- 50-state CARB emissions legal (E.O. #D-215-102)
The new CARB-legal Edelbrock Cylinder Heads for the 6.6L Duramax Diesel engine are available now and are a perfect choice for a street performance upgrade to your Duramax Diesel engine. Watch the Edelbrock Blog for an installation and performance review of the new heads.
Brian Hatano is a veteran automotive journalist and former editor of Car Craft, Petersen’s Drag Racing, Sport Compact Car and Motorcyclist magazines.