Three Reasons Why Your Subaru Engine Might Fail You

When pushing your Subaru engine to higher performance levels, it's crucial to understand potential failure points to ensure reliability on and off the track. Here are three main reasons why your engine might fail:

1. Leaking or Blown Head Gasket: High-performance engines are prone to increased cylinder pressures, which can lead to leaking or blown head gaskets. This issue compromises engine sealing and can result in coolant leaks or mixing with oil, necessitating immediate attention to prevent further damage.
2. Cracked Cylinder Walls from High Pressure or Boost: Increased cylinder pressures from high boost levels can cause stress on cylinder walls, potentially leading to cracks. Without sufficient support, cylinder walls may deform or crack under extreme conditions, jeopardizing engine integrity and performance.
3. Spun Engine Bearings and Loss of Oil Pressure: Subaru EJ engines, known for their performance capabilities, can experience bearing failure under high stress. Misalignment of main bearing bores can exacerbate this issue, leading to loss of oil pressure and eventual bearing failure. This problem requires precise machining and alignment to maintain stable clearances under heavy loads.

 

How to Race Without Engine Worries

At HCR, we've developed proven solutions to address these common Subaru engine challenges, ensuring reliability and performance:

• Closed Decking: Machining the engine case to accept CNC machined inserts provides full support to cylinder walls, especially at the combustion point. This reduces the risk of cylinder wall movement under pressure and maintains efficient engine cooling.
• Vertical CNC Line Boring: Corrects main bearing bore alignment issues by precisely machining the case halves. This prevents bearing failures caused by improper clearances and ensures consistent performance under high loads.
• Mains Pinning: Machining pins into Subaru case main webs reduces distortion and flex caused by high boost and cylinder pressures. This process strengthens the engine case and enhances bearing life, crucial for sustained performance on the track.

 

Our Proven Solutions

These solutions have been extensively tested and refined, drawing from our experience with over 300 engine blocks across Europe. By integrating closed decking, line boring, and mains pinning, you can significantly enhance your Subaru engine's durability and performance.

Conclusion

Investing in these upgrades—closed decking, line boring, and mains pinning—not only ensures reliability but also enhances your Subaru's capability to handle high-performance demands. Stay ahead on the track and avoid engine troubles with our tested and proven solutions.

Contact Us

For more information on how to implement these upgrades or to discuss your specific engine needs, contact us today. We're here to help you optimize your Subaru engine for ultimate performance and reliability.