mountune Focus ST High Performance 2.3L Stroker Short Block
Ford EcoBoost 2.3L
Focus ST 2013-2018
The perfect way to increase displacement and add performance when rebuilding your Focus ST engine.
mountune’s extensive knowledge of the Ford EcoBoost engine coupled with broad motorsport experience provides the foundation for our Premium High Performance 2.3L Ford EcoBoost short block. Each short block is skillfully assembled using a brand new Ford engine block coupled with mountune Forged Pistons, Forged Connecting Rods and high performance bearings. This short block is the perfect foundation for your Focus ST for high boost applications including track day use. We take the guess work out of critical engine assembly allowing you to install your existing cylinder head and other base engine components to this premium improved foundation.
Short Block Features
The engine block is first inspected, de-burred, and the bores are honed to perfection to receive mountune Forged Pistons. The rotating assembly that includes a new Ford RS Forged 94mm crankshaft and mountune Forged Connecting Rods is balanced to within .5 gram. The select parts are professionally assembled by one of mountune's skilled engine builders using tri-metal race spec bearings.
Each assembly includes a detailed data sheet showing all critical engine dimensions.
Compression Ratio 9.5:1
- New Ford EcoBoost ST Engine Block
- New Ford RS 94mm Forged Crankshaft
- mountune Forged Connecting Rods
- mountune Forged Pistons and rings
- mountune, Tri-metal bearings w locating tang
- Assembly balanced to within .5 gram
- Complete blue-print assembly
- Ring gap set
- Bearing clearance set
- Deck height checked
- Connecting Rod side clearance set
- Crankshaft end float set
- Balance shaft delete
Engineered in house by our motorsport division and manufactured exclusively by our partner Mahle Motorsports, the mountune forged piston set for the 2.3L Ford EcoBoost is a fully featured piston with many of the same upgrades we use in our professional motorsport engines. Produced from modern 4032 lightweight alloy forgings for maximum oil control and quiet operation, each piston features supported pin bosses to withstand the extreme conditions found in engines operating with high cylinder pressures. The layout of the piston has also been optimized with weight reduction in mind and reduced skirt profiles to minimize friction.
Mountune pistons also include gas accumulator grooves developed during extensive testing and tailored for the EcoBoost engine. Careful consideration has been used in the “bowl” area of the piston to maintain Ford’s original profile to ensure proper and efficient combustion. Tool steel 22mm internally tapered, short wrist pins are used to reduce pin flex and weight. Mountune connecting rods are recommended to ensure a matched set of components. As an added feature, Mahle's phosphate dry lubricant coating is used on the entire piston to reduce micro-welding and pin galling. Additionally, Mahle's Grafal skirt coating is used on the piston skirt to reduce cylinder wall friction reduction. Hard anodized top ring grooves have been incorporated for increased durability and strength to withstand the high cylinder pressures of high boost engines.
- 1.2mm gas nitrided top ring: Superior combustion sealing, strength and wear compared to traditional 1.0mm steel top rings.
- 1.2mm gas nitrided second ring: Superior strength and wear compared to traditional iron second rings.
- 2.0mm soft nitrided oil rings: Superior strength and sealing properties compared to traditional 2.8mm rings
Connecting Rod Features
The connecting rod is one of the most highly stressed components within the engine and improved connecting rods are an essential upgrade for high power EcoBoost engines. The mountune connecting rod was developed using extensive FEA analysis resulting in the optimum connecting rod for applications up to 200 bhp per cylinder. Made in the USA by Carrillo to our specifications, each connecting rod incorporates our motorsport DNA to provide you with the ultimate component for your engine. Exclusive features include a robust, I – Beam configuration with extensive machining to optimize weight without reducing strength. All edges and corners are radiused to improve durability.
As an added upgrade, mountune connecting rods feature machined tangs to securely locate the rod bearings. Compared to the factory press fit tangless bearings, this feature ensures improved bearing retention in high cylinder pressure and high RPM engines. Tool steel connecting rod bolts are also standard and are superior to most bolts found in other rods on the market. Silicone/bronze pin bushings provide a durable and low friction surface that remains dimensionally stable in high pressure and high RPM applications.
- Center to Center : 6.139"
- Pin Bore 22mm
- 3/8" WMC Tool steel rod bolt
- Nominal weight : 561g
This part has been designed and is intended for off-highway application only. Installation of this part on a vehicle that is driven on public roads may violate U.S. and Canadian laws and regulations relating to emission requirements and motor vehicle safety standards. Click Here
for Emissions compliance information.