mountune High Performance 2.3L MRX Stroker Focus ST Long Block

Mountune's extensive knowledge of the Ford EcoBoost engines coupled with our comprehensive motorsport experience provides the foundation for our premium 2.3L Ford EcoBoost long block assembly.

Each long block starts off as a brand new aluminum Ford Focus ST engine block then skillfully assembled with mountune Focus RS forged pistons, Focus RS forged connecting rods, tri-metal racing bearings, and a keyed OEM Focus RS crankshaft.

Each High Performance 2.3L MRX Long Block is topped with a mountune MRX Cylinder Head - Focus ST. A factory Focus ST cylinder block that has undergone our precision MRX machining service for the best possible performance, increasing intake airflow by 44% and exhaust airflow by 19%.

The mountune MRX cylinder head for the Focus ST also features high-performance black nitrided intake valves, sodium inconel exhaust valves, along with our motorsport valve stem seals, and your choice of V2 or V3 camshafts.

This engine is the perfect foundation for your Focus ST for high boost applications including track day use or as a direct replacement for your tired original engine.

Camshaft Information

• The V2 Camshafts offer good all around drivability while providing excellent power and response. We recommend these for most applications.
• The V3 Camshaft option works well with larger than stock turbochargers and enhances high RPM power level. Because of the longer duration and higher lift, rough idle should be expected and considerable tuning effort may be required for these camshafts to function correctly.

Important Notice: Extended Lead Times

Due to high demand and ongoing parts supply delays, our custom-built-to-order engines are experiencing extended lead times. We’re committed to quality and appreciate your patience. For the latest lead time estimates, please contact us.