Today we made our way over to Ford's Beech Daly Technical Center, a nondescript building along the Dearborn side roads which houses what is, for lack of a better term, Ford's engine skunk works. Capable of doing everything from rapid-prototyped vinyl intakes to turning out fully functioning engines, the tech center is where all Ford's engines go to get the bugs worked out. Our mission was to get to know the 3.5-liter Ford EcoBoost on a nuts-and-bolts level by putting one together ourselves.
We met up with Patrick Hespen from SVT communications, who guided us through the rows of workbenches stacked high with engine parts from every imaginable engine product. Deep in the back was a set of parts which, when fully assembled, would form a production-intent twin-turbocharged, 340 HP, 340 lb-ft Ford EcoBoost engine. You know, the one they're touting as a V6 which delivers the power of a V8.
The beauty of the EcoBoost system is that it takes relatively few changes to go from a standard 3.5-liter V6 to a fire-breathing, twin-turbo monster developing peak torque at 1500 RPM. What it all boils down to is the combination of direct injection and two turbos. Those two main updates drive the smaller, but smartly executed, changes around them.
So, let's follow the fuel through the engine: The first difference the gas sees is the addition of a mechanically actuated, high-pressure fuel pump. The pump rides on top of the drivers' side cylinder bank and gets its motive power from a four-sided cam lobe, brilliantly added to the intake cam. The fuel then passes into a high-pressure (like 3000 PSI high) stainless-steel common fuel rail to which is mounted three injectors, one assembly per side. The injectors are mounted to the underside of the cylinder head and poke into the distal edge of the compression chamber.
Since the system direct-injects fuel into the chamber, games can be played with the actual flow of the spray. For instance, on start up, when the engine is cold and the catalysts aren't functioning, the engine injects a half-shot of fuel into chamber on the downward stroke of the intake cycle, then, as the piston comes back for ignition, a second half-shot is fired at the piston head. Notice the shape of top of the piston (sans the CNC'd EcoBoost logo): The little trough is designed specifically to ramp that secondary spray at the spark plug — the result is a locally rich mixture good for ignition, but a globally lean mixture, great for making heat fast.
As the spent fuel leaves the combustion chamber, it meets another innovative feature: a stainless steel, stamped and welded two-walled exhaust manifold. The manifold is much lighter than its cast counterparts, but more importantly, its insulative properties keep the exhaust hotter, transferring more energy directly to the turbo. Speaking of the turbo, surprisingly, when we get to the turbo we find nothing notably exciting. The impeller side of turbo itself is made of a high-nickel-content alloy good for an operating temperature up to 950 degrees Fahrenheit. The compressor side, while rated up to 220,000 rpm maximum speed, isn't really all that different than the one found on every other turbo on the market.
Since the gas is spent, we're going to hop onto the intake air side now. That air gets compressed by the two turbos we just met, and then joins in a common tube. That tube has an electronic boost controller which dumps excess pressure electronically, instead of the "Fast and Furious" approved vacuum-driven blow-off valve. The air then makes it's way into an air-to-air intercooler, and the cooled air heads off to an all-new intake manifold, optimized for compact packaging and easy assembly. An interesting feature is the integration of the coolant pipe which runs under the whole length of the intake; it attaches at the rear to the coolant line in the valley and locates the thermostat and outlet for the heater core out of the way. Anyway, that air gets directed straight into the cylinders by valves enhanced with Inconel alloy for greater strength.
Because we're engine geeks, there are myriad little details and upgrades we could go on about, like the addition of piston head oil sprayers, used to keep the piston head cool by hitting the bottom side with oil, and how they're brilliantly integrated into the crankshaft bearing oil pocket. Or the million miles of durability testing the engine has already undergone. Or the crazy ability to retard the timing up to 20 degrees...but we won't. We're happy to sit back and let the pictures do the rest of the talking, eagerly awaiting the day we get to put that bonkers power curve to the test.
Gallery: Ford's EcoBoost Build