3.5l Ecoboost  Generations Explained.

WHAT IS ECOBOOST? 

3.5L V6 ECOBOOST GENERATIONS EXPLAINED

The Ford EcoBoost engine, particularly the 3.5-liter variant, stands as a testament to the advancements in automotive technology. Ford's EcoBoost series, introduced in 2009, revolutionized the concept of power and efficiency in engines. The 3.5-liter V6 EcoBoost, in particular, has evolved across several generations, each marked by significant technological improvements. This article delves into the developmental journey of the 3.5L EcoBoost, exploring its inception, the distinguishing features of each generation, and how these innovations have shaped its performance and reliability. From its initial launch to the latest iteration, the 3.5L EcoBoost demonstrates Ford's commitment to combining power with fuel efficiency, reflecting the evolving trends and demands of the automotive industry.

FORD ECOBOOST 3.5L GEN 1

Overview:

Originally dubbed “TwinForce” when introduced on the 2007 Lincoln MK-R Concept Vehicle,  Ford put the automotive world on notice with an all new twin-turbocharged direct-injected V6 engine in their lineup.  After being renamed to “Ecoboost” with the 2008 Lincoln MKT concept vehicle, the engine saw production in May of 2009 at Cleveland Engine Plant #1.  The first commercially available vehicles to feature the all new 3.5L Transverse Ecoboost V6 were the 2010 Lincoln MKS & MKT, Ford Flex, Taurus and Explorer Sport. 

In 2011 Ford went all-in on EcoBoost and their Gen1 3.5L V6 now powered the legendary F-150.  Designed to match the power of the outgoing V8 engine while producing 15% better fuel economy, these turbocharged Ecoboost engines made good on their promise - proving reliable and powerful.  The Gen1 3.5L Ecoboost V6 was eventually fitted to other Ford vehicles like the Expedition/Navigator and remains in production today powering the Ford Transit EcoBoost Van.

Technical Details:

Gen1 3.5L EcoBoost is based on the Duratec 3.5 V6 aluminum engine block. This engine utilizes gasoline direct injection (2150 PSI) for maximum knock resistance, fuel efficiency and performance.  Gen1 powered F-150 trucks feature twin BorgWarner turbochargers tuned to produce 15 PSI of boost. Despite the added boost, the first generation Ecoboost V6 engines only require regular-grade gas (but we recommend premium fuel for best reliability and performance!)

2011-2012 saw the early Gen1 3.5L F-150 engines with the smallest turbos and an integrated BOV on the turbo's compressor housing. These trucks used Hitachi fuel and timing systems.  The exhaust manifold was cast iron and fastened with mild steel studs, susceptible to warping.  

2013-2016 updated the 3.5L with larger turbos, an electronic BOV, and utilized Bosch fuel system components. The Final evolution of the Gen1 is found on the 2017+ Transit van which retained all of the 2013-2016 foundation adding revised timing components and updated 6R80 transmission tuning.

The Gen1 bottom end consists of a reliable forged steel crankshaft with 6 bolt mains. Steel rods are attached to cast aluminum pistons with floating wrist pins, a steel ring carrier and a coated skirt to handle the boost. Oiling is a traditional gerotor oil pump with fixed oil pressure. The cylinder heads use a shimless-bucket valvetrain that's proven to be exceptionally reliable. Finally, the timing system features one long primary timing chain and two secondary chains.  The primary chain may stretch/wear (generally above 150k miles) and may be replaced with the .

Gen1 3.5L Applications:

  • 2011–2016 Ford F-150: 365 hp, 420 lb-ft of torque
  • 2015–2017 Ford Expedition, Lincoln Navigator: 380 hp, 460 lb-ft of torque
  • 2013-2025 Ford Transit Van: 310 hp, 400 lb-ft of torque

FORD ECOBOOST 3.5L GEN 2

Gen2 Overview:  

The 2nd Generation 3.5L Ecoboost V6 benefitted from everything Ford learned to this point.  An all-new clean sheet design, Gen2 3.5L was introduced at the 2015 Detroit Auto Show with the 2016 Ford GT, their storied carbon fiber supercar, producing 647 hp.  The GT featured Garrett turbochargers on merge collector manifolds, with metal timing chain guides.

This was quickly followed by news of a massive $145 million investment in Clevelend Engine Plant to support this new engine.  Jimmy Settles, UAW vice president, National Ford Department said: “The team at Cleveland Engine is thrilled to begin building one of the most technologically advanced engines ever designed for the all-new F-150 Raptor.”

Powered by this all-new second generation 3.5L twin-turbo Ecoboost V6 paired with an all-new 10R80 10-speed automatic transmission (developed in partnership with General Motors) the Raptor High-Output version produced 450 horsepower, a considerable increase from the previous V8 powered Raptor’s 6.2L 411 horsepower V8 engine.  The 2017+ F-150 version of the Gen2 Ecoboost produced 440 horsepower and 510 lb⋅ft of torque.  Gen2 Ecoboost V6 saw production across the 2017-2020 Ford Raptor, F-150 Limited/Platinum and optional in other F-150 models. 

 

Gen2 Technical Details and Improvements from Gen1 Ecoboost:

The Gen2 Ecoboost engine is completely different from the Gen1 engine.  Despite having structurally similar bore spacing and rod length/stroke, the engines are not the same.  The increased horsepower rating of the 2nd Gen Raptor 3.5L HO necessitated increased fueling and the biggest change between Gen1 and Gen2 Ecoboost V6 engines is it's Dual-Injection fuel system; Ford added 6x port injectors on top of the 6x direct injectors (at 2400psi rail pressure!).  The Bosch engine computer controlled all 12 injectors independantly and allowed the port + direct injection to operate separately or in conjunction with each other. At low RPM or low load the engine will operate on the port injectors only, while higher demands will activate the direct injection system. During cold start both fuel systems are active, reducing soot emissions.  And from a reliability standpoint, the port injectors spray fuel on the back of the intake valves and prevent buildup.

The 2017 Gen2 Ecoboost received many upgrades to it's twin BorgWarner turbochargers.  Visibly recognizable are electronic stepper-motor wastegates aka "E-Gates" to allow increased boost compared to the soft Gen1 wastegate spring.  The Gen2 HO turbine wheels featured MAR-M-247 Super-alloy material along with larger compressor wheels, visably sharper blade angles for improved response, efficiency and performance.  In 2018-2020 Ford went one final step further with a ported-shroud compressor housing and highest flowing wheels across all Gen2 3.5L engines.

Of particular note, Gen2 3.5L saw significant timing system changes to reduce harmonics and increase strength, minimizing the chain stretch that is common with the Gen1 3.5L Ecoboost engines.  Ford switched from a long single primary chain system to a stronger and more robust dual primary chain system. The chains themselves are shorter in length and received a strength upgrade, with thicker side plates. To accommodate the new dual chain system the crank gear was also converted to a dual drive sprocket.

The cylinder heads received significant valvetrain upgrades starting with a roller-rocker and hydraulic lifter (like Ford's Gen2 Coyote 5.0L engine).  These attach to larger diameter hollow stem intake valves and sodium filled exhaust valves, each with triple valve locks.  Gen2 3.5L Cam phasers are a wear item, and when the "HL3Z" Gen2 phasers rattle the solution is install the "ML3Z" cam phaser from the Gen3 2021+ engine.  (Note: the last Gen2 engines produced in 2020 used the updated Gen3 Phasers and Gen3 rockers/lifters.)

The bottom end of the engine was updated, but not as dramatically.  A new block casting and a slightly stronger forged crank were implemented.  Connecting rods remain identical between the Gen1 and Gen2 engines. The undersides of the pistons underwent a redesign to better transfer heat back into the oil.  Oil volume was increased with a variable-pressure oil pump and all Gen2 3.5L now used piston-cooling oiling jets for additional durability.  Compression was adjusted to a lower 10.5:1 ratio in F-150 and 10:1 in Raptor to accomodate additional boost.  The overall weight of the engine was reduced by 4 lbs with the changes outlined above. Finally, an auto start/stop system was added to decrease emissions during city driving.

Gen2 3.5L Applications:

  • 2017–2020 Ford F-150 Raptor HO: 440-450 hp, 510 lb-ft of torque
  • 2017–2020 Ford F-150 3.5L: 375 hp, 470 lb-ft of torque
  • 2018–2022 Ford Expedition / Navigator HO: 400 hp, 480 lb-ft of torque
  • 2018–2022 Ford Expedition / Navigator: 375 hp, 470 lb-ft of torque