High-quality aircooled engine machining solutions designed for maximum accuracy and reliability.
At JS Auto Tuning & Performance, we provide specialised machining for classic air-cooled engine crank cases. Whether you’re restoring a classic Volkswagen or assembling a performance engine, our precision services ensure your case is straight, within tolerance, and ready for your build.
With a deep understanding of air-cooled engine design, we can re-machine or modify your engine components. Our commitment to quality, accuracy, and proper clearances ensures your build has the foundation it needs to perform.

Case Machining
We offer comprehensive case machining tailored to original-spec restorations and high-performance builds:
- Line Boring: Precision align boring to correct main bearing saddle wear and restore factory alignment.
- Cylinder Boring: Accurately bore case for larger cylinders to match new piston and cylinder kits.
- Full Flow Oil Modifications: Improve oil cooling and filtration by adding a full flow system.
- Thrust Cutting: Restore proper endplay by machining thrust surfaces to factory or custom specs.
- Hoover Modifications: Improve oiling efficiency and longevity with essential case upgrades.
- Crack Inspection and Thread Repair: Ensure your case is solid and ready for power by have case savers installed.
Cylinder Head Services
From daily drivers to performance builds, our cylinder head services deliver flow, reliability, and longevity:
- Head Boring and Fly Cutting: Increase compression or deck precision to match your build requirements.
- Valve Seat Installation and Cutting: High-quality seat replacement and multi-angle valve seat cutting for optimal flow and performance.
- Valve Guide Replacement: Silicone bronze guides installed and honed for proper stem clearance and oil control.
- Porting and Polishing: Improve airflow for better power and response.