4JJ1 Main Cap Girdle

It's no secret that 4JJ1 engines can and do suffer broken crankshafts with an increase in horsepower. Why, is arguably the most debated topic in the 4JJ1 scene. 

We've designed and developed a girdle that we believe does improve the rigidity and harmonics within the bottom end to help prevent cranks from snapping. 

• The girdle is completely DIY friendly and comes with upgraded fasteners. 
• This is a bolt on kit that clears both standard cranks and also MRX cranks. 
• CNC Precision machined 
• High-strength engineered steel specifically suited for girdle application.    

An engine girdle, also known as an engine main support system or main cap girdle, is a device used in automotive engines to provide additional support and strength to the main bearing caps of the engine block. Here are some benefits of using an engine girdle:

1. Increased Rigidity:

   • Engine girdles are designed to add rigidity to the engine block by tying the main bearing caps together. This helps reduce flex and distortion of the block under heavy loads or high RPMs, leading to improved overall stability.

2. Enhanced Block Strength:

   • The girdle reinforces the main bearing caps, which are crucial components for supporting the crankshaft. By adding strength to these components, the engine can withstand higher levels of stress and load.

3. Reduced Vibrations:

   • A stiffer engine block can help reduce vibrations and harmonics, which can contribute to smoother engine operation. This is especially beneficial at high RPMs where vibrations can become more pronounced.

4. Improved Bearing Alignment:

   • The girdle helps maintain proper alignment of the main bearing caps, ensuring that the crankshaft stays in its intended position. This can contribute to better oil clearance and overall improved bearing performance.

5. Enhanced Performance:

   • By reducing block flex and improving overall stability, an engine girdle can contribute to improved engine performance. This is particularly important in high-performance applications where the engine is subjected to extreme conditions.

6. Prevention of Crankshaft Deflection:

   • The girdle can help prevent excessive deflection of the crankshaft, especially in high-performance or racing applications. This can contribute to increased durability and longevity of engine components.

7. Support for Aftermarket Components:

   • In cases where an engine has been modified with aftermarket components, such as a high-performance crankshaft, connecting rods, or increased horsepower, an engine girdle can provide additional support to handle the increased stresses.

8. Reduced Risk of Main Cap Walk:

   • Main cap walk refers to the lateral movement of the main bearing caps. The girdle can help minimize this movement, ensuring that the caps stay in their proper positions and maintain proper alignment.

Package includes: 

• Girdle 
• Fasteners

 Vehicle application:

• Isuzu D-Max 3.0L 2016-2020 DPF model 
• Isuzu D-max 3.0 2012 - 2015 pre dpf model 
• Isuzu D-Max 3.0 2009-2011 
• Holden Rodeo 3.0L 2007-2008
• Holden Colorado 3.0L 2008-2012