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The 4G63 engine has gained a reputation for its performance potential, especially in the world of tuning and racing. To achieve power outputs of 800+ horsepower, significant modifications are necessary. This article will explore the key machining processes and reinforcements that can be applied to the 4G63 block to ensure it can handle such extreme power levels.
Understanding the 4G63 Engine
The 4G63 is a 2.0L inline-four engine produced by Mitsubishi. It is known for its robust design and has been used in various models, including the Mitsubishi Eclipse and Galant. The engine features a DOHC design and is capable of producing impressive power when properly tuned.
Common Weak Points of the 4G63 Block
Before discussing the modifications, it’s essential to understand the common weak points of the 4G63 block that can limit its performance:
- Thin cylinder walls
- Weak main caps
- Insufficient oiling system
- Head gasket failures
Machining Techniques for Strengthening the Block
Boring and Honing
Boring and honing the cylinders can improve the engine’s ability to handle higher power levels. This process involves:
- Boring the cylinders to a larger diameter to accommodate larger pistons.
- Honing the cylinder walls for a smoother finish, which helps with piston ring sealing.
Decking the Block
Decking the block ensures a flat surface for the head gasket, which is crucial for maintaining compression and preventing leaks. This process can also increase the compression ratio, contributing to better performance.
Resurfacing the Main Caps
Resurfacing the main caps can help improve the alignment of the crankshaft and reduce flex under high power conditions. This step is vital for maintaining the integrity of the engine under stress.
Reinforcements for the 4G63 Block
Main Cap Studs
Replacing the factory main bolts with main cap studs can significantly improve the clamping force on the main caps. This upgrade helps prevent movement of the caps under high load, which is essential for high horsepower applications.
Block Filling
Block filling involves adding a material such as concrete or epoxy to the water jackets of the engine block. This process increases rigidity and helps support the cylinder walls, reducing the chance of flex during high power situations.
Studding the Cylinder Head
Using head studs instead of bolts can improve the clamping force on the cylinder head. This upgrade is crucial for preventing head gasket failures when running high boost levels.
Improving the Oiling System
To support higher horsepower, the oiling system must be upgraded to ensure adequate lubrication. Key improvements include:
- Upgrading to a high-capacity oil pump.
- Installing oil restrictors to manage oil flow effectively.
- Adding an oil cooler to maintain optimal operating temperatures.
Conclusion
Strengthening the 4G63 block for 800+ horsepower involves a combination of machining techniques and reinforcements. By addressing the weak points and implementing these modifications, enthusiasts can maximize the performance potential of this legendary engine. With the right approach, the 4G63 can become a powerhouse capable of competing at the highest levels of motorsport.