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The Mopar 426 HEMI is an iconic engine known for its power and performance. In this article, we will explore how to transform a stock 426 HEMI into a beastly 550 horsepower powerhouse using upgrades from Summit Racing.
Understanding the Mopar 426 HEMI
The 426 HEMI was introduced in the 1960s and quickly became a favorite among muscle car enthusiasts. With its distinct hemispherical combustion chambers, the HEMI design allows for better airflow and combustion efficiency, resulting in impressive power output.
Key Components for the Build
- Engine Block
- Crankshaft
- Pistons
- Camshaft
- Intake Manifold
- Carburetor
- Exhaust Headers
- Ignition System
Engine Block
Starting with a solid engine block is crucial. The stock 426 HEMI block can handle significant power, but for this build, we recommend reinforcing it to ensure durability under high performance conditions.
Crankshaft
Upgrading to a forged crankshaft will enhance strength and reliability. A lightweight crankshaft will also improve the engine’s responsiveness, making it ideal for high RPMs.
Pistons
Using high-compression pistons will significantly boost power output. Look for pistons that are designed for performance applications to maximize the engine’s potential.
Camshaft
A performance camshaft can dramatically alter the engine’s characteristics. Choosing a camshaft with a higher lift and longer duration will increase airflow and power, allowing the HEMI to reach its full potential.
Intake Manifold
An aftermarket intake manifold designed for high performance will improve air distribution to the cylinders. This upgrade is essential for achieving the desired horsepower level.
Carburetor
To fuel the increased airflow, a larger carburetor is necessary. A dual-quad setup can provide the additional fuel needed for higher horsepower while maintaining optimal performance.
Exhaust Headers
Upgrading to performance exhaust headers will reduce back pressure and improve exhaust flow. This upgrade is crucial for maximizing horsepower and enhancing the engine’s sound.
Ignition System
A high-performance ignition system will ensure reliable starting and optimal combustion. Consider upgrading to an electronic ignition system for better timing and efficiency.
Assembly Process
Once all components are gathered, the assembly process can begin. It is crucial to follow a systematic approach to ensure everything fits and functions correctly.
Preparing the Engine Block
Clean the engine block thoroughly and inspect it for any damage. Ensure all surfaces are smooth and free from debris to facilitate proper sealing and assembly.
Installing the Crankshaft and Pistons
Carefully install the crankshaft, ensuring it is properly aligned. Next, install the pistons, making sure to follow the manufacturer’s specifications for clearance and torque settings.
Adding the Camshaft and Timing Components
Install the camshaft along with the timing chain or belt. Proper timing is essential for engine performance, so double-check all settings before proceeding.
Mounting the Intake Manifold and Carburetor
Secure the intake manifold to the engine block, ensuring a tight seal. Attach the carburetor, making sure to adjust the float levels for optimal fuel delivery.
Installing Exhaust Headers
Install the exhaust headers, ensuring a proper fit to minimize leaks. This is a critical step for maximizing exhaust flow and overall performance.
Setting Up the Ignition System
Finally, install the ignition system components, ensuring all connections are secure. Proper ignition timing is crucial for achieving maximum horsepower.
Tuning for Performance
After assembly, tuning the engine is necessary to achieve the desired horsepower. This involves adjusting the carburetor, ignition timing, and other parameters to optimize performance.
Carburetor Tuning
Start by adjusting the air-fuel mixture. This can be done by tuning the jets in the carburetor. A richer mixture may be necessary to support the increased power output.
Ignition Timing Adjustment
Adjust the ignition timing for optimal performance. A timing light can help ensure that the engine is firing at the correct point in the cycle for maximum power.
Final Testing
Once tuning is complete, conduct a series of tests to ensure the engine performs as expected. Monitor horsepower and torque outputs to confirm the build meets the 550 HP target.
Conclusion
Transforming a stock 426 HEMI into a 550 horsepower beast is an exciting project that requires careful planning and execution. By utilizing high-quality upgrades from Summit Racing, enthusiasts can achieve remarkable power and performance from this legendary engine.