2.3L Stroker EcoBoost Engine Assemblies


Mountune's extensive knowledge of the Ford EcoBoost engines coupled with our comprehensive motorsport experience provides the foundation for our stroked 2.3L Ford EcoBoost engine assemblies.

Each long block starts off as a brand new aluminum Ford Focus ST engine block. To ensure excellent gasket sealing, we de-burr all edges and then resurface the head gasket sealing surfaces on both the engine block and cylinder head.

All rotating components including the crankshaft, connecting rods, and pistons are all dynamically balanced to Formula One standards at 0.5 grams. All critical dimensions such as bearing clearance are measured and set for optimized performance.

Increased Displacement for More Power and Torque

The mountune Focus ST stroker engine is 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 to increase the engine's overall displacement to 2.3 liters.

Engine Specifications:

Base Engine 2.0L Ford EcoBoost
Bore X Stroke Φ 87.5mm x 94 mm
Compression Ratio 9.5:1
Piston Upgraded Forged Piston
Connecting Rod Mountune Forged H Beam Rod (N1)
Mountune Forged I Beam Rod (MRX)
Crankshaft OEM Focus RS w/ 3mm Key
Main Bearing Mountune Race Tri-Metal
Main Bolts OEM High-Tensile Strength
Application Focus ST 2013-2018



Each High Performance 2.3L Stroker MRX Long Block is topped with a mountune MRX Cylinder Head. 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

  • V2 Camshafts offer good all around drivability while providing excellent power and response. We recommend these for most applications.
  • 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.

Comparison Chart:


Short Block

SKU: 6063-SB-230

N1 Long Block

SKU: 6063-LB-232

MRX Long Block

SKU: 6063-LB-233

Engine Block Factory New Ford OEM Aluminum 2.0L EcoBoost Closed Deck Engine Block
Pistons Lightweight 87.5 mm Bore 9.5:1 Compression Ratio Focus RS Forged Pistons w/ Nitrided Rings
Connecting Rods High-Tensile Strength Forged 4340 Alloy Steel Focus RS H-Beam Rods w/ ARP 2000 Bolts High-Tensile Strength Forged 4340 Alloy Steel Focus RS I-Beam Rods w/ ARP 2000 Bolts
Crankshaft Dynamically Balanced and Keyed Ford OEM Focus RS Forged 4340 Steel 94 mm Stroke Crankshaft
Oil System Not Included Mountune Baffled Oil Control Sump and High-Pressure Oil Pump
Fasteners Not Included Premium Grade 8740 Alloy High-Performance Cylinder Head Studs w/ Black Oxide Finish
Cylinder Head Not Included Ford OEM 2.0L Ecoboost DOHC w/ Variable Camshaft Timing Aluminum Cylinder Head Mountune MRX Focus ST Cylinder Head w/ Motorsport-Grade Valves and V2 Camshafts
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Additional Photos:

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