How did Ford make the 3 cylinder 1.0 liter EcoBoost unbelievably quiet and smooth?

Three cylinder engines are generally harsh and noisy, a problem we automotive enthusiasts like to brush under the rug with the blanket label we call ‘character’ of the automobile. The ones that are tolerable have a counter-rotating balancer shaft to cancel out the vibrations. This additional component makes the engine heavy, expensive and in general less efficient. Ford decided not to have a counter balancer. Auto journos who have driven the 1.0 litre EcoBoost powered Ford Focus ( Indian journos drove the 1.6 Flex Fuel powered EcoSport in Brazil) have come away stumped at the smoothness and quietness of the 3 cylinder mill. How did Ford pull this one off?

The thing about engines with even number of cylinders, say a four cylinder engine is that for every piston at the top dead centre of the cylinder about to change direction, there’s another piston at the bottom in another cylinder also about to change direction. In a three cylinder you have three cylinders firing unopposed and if we may say so unabashed. Without the balancer shaft, the NVH levels would test occupants tolerance to the limit.

The 1.0-liter EcoBoost’s NVH engineering team, led by Andy Delicata at Ford Technical Centres in Dunton and Dagenham, England, worked to solve the problem by using an unbalanced front pulley and rear flywheel. The pulley and flywheel have weights placed precisely to counteract the ‘natural shaking forces’ of the engine. In addition to this, the engine mounts are designed to decouple as well as absorb the engine’s shaking forces, Delicata explained.

The result is one of the smoothest and quietest engines in Ford’s global lineup says Ford. “We like to compare the refinement of the 1.0-liter EcoBoost engine with what you would typically experience in a vehicle two or three classes up from Fiesta and Focus,” said Delicata.

Now that the issue of vibrations were dealt with the other task was to ensure the noise levels were kept to the minimum. We’ve spoken at length about how compact the 1.0 litre EcoBoost engine is. The footprint is said to be as big as a sheet of A4 sized paper and is compact enough to fit into hand luggage. Ford opted to use a highly stiff cast-iron block structure and an integrated engine mounting bracket which are highly effective in absorbing noise energy. Ford engineers have also immersed the engine’s toothed rubber timing belt in oil to reduce noise during operation. Isolated fuel injectors are electronically controlled for ‘soft landing’ and a foam-covered engine collectively help keep noise and vibration from reaching the driver.

The 1.0-litre EcoBoost engine also features a new compact, high performance turbocharger design. The extremely fast response of the turbocharger and its ability to reach nearly 250,000 rpm results in virtually no turbo lag and peak torque of 170 Nm. The all-new EcoBoost engine also features an exhaust manifold cast into the cylinder head, which lowers the temperature of the exhaust gases and in turn enables the engine to run with the optimum fuel-to-air ratio across a wider rev band. An advanced “split cooling” system reduces fuel consumption by warming the engine more quickly. Opting for cast iron instead of aluminium has also reduced the amount of energy needed for warm-up by up to 50 per cent compared with aluminium.

The thing about technology is that while factors like efficiency and cost matter, the ultimate deal breaker is acceptability by the masses. In our opinion, acceptability comes with the extent to which the change is imperceptible. Give the people a 1.0 litre three cylinder that gives them as much performance as a 1.6 four cylinder yet delivers astounding fuel efficiency, while ensuring all the while that the customer forgets the fact that he is driving an EcoSport/Focus/Fiesta that is powered by an engine that plays host to a large number of the latest Ford innovations, and you have a winner already.