Classic Ford, April 2017 – 1.6L EcoBoost

Words and Photos Jon Hill

 

Once you start something you just can’t stop. We’ve already examined the astonishing 1-litre EcoBoost with its power potential that is good for around 350bhp (see February 2017 issue). Now it’s the turn of the 1.6, and we have to tell you, it too is capable of producing ridiculous horsepower and its origins may also surprise you!

 

EcoBoost is of course Ford’s name for its series of ultra-lean burn engines that use direct-cylinder injection (DI), plus variable valve timing coupled with a small turbo spinning up from virtually nothing. When you then add to the mix as many modern engine tricks as you can think of, the combination’s good for super-strong power and torque figures with excellent future potential. Admittedly, the 1-litre’s figures were achieved with component changes but specialists, SBD Motorsport have so far approached the 1.6 using no internal modifications at all – they haven’t even got as far as changing the rods and pistons yet – or even the cams!

 

Naturally, we want to see what the future holds for classic Ford performance so we’ve invited SBD’s Steve Broughton to guide us through the technical details of this EcoBoost, reporting on the strides they’ve made and so far that’s to 301bhp. And there’s a lot more to come.

 

EcoBoost and Sigma: the connection

The 1-litre EcoBoost is one of Ford’s newest engines, but the 1.6 is very different and is a development of the previous Sigma series using in the Fiesta, focus and Puma. And you may well be confused because that engine was also known as the Zetec SE – and nothing to do with the Zetec Silver or Black Top we’re more familiar with. With masses of input by Yamaha, the engine featured an all-alloy block, alloy 16-valve head, similar oil-directing channels down the outside of the block as the Mazda-derived Duratec and the same-pattern, high-spec cast, high-revving crank that sat up inside the block housed within its own alloy cradle.  We’ll examine it in more detail but the 1/6 EcoBoost has an almost identical Sigma block although the head is completely different encompassing that all important direct-cylinder injection.

 

Direct Cylinder Injection

This is almost identical technology to current diesel engine design; where the fuel injector is extremely high pressure, its flow variable controlled by the ECU, but mounted right inside the combustion chamber and in this case, directly overhead.  There are also some US-based engines where the injector is not overhead but slightly mounted to the side “These we refer to as more port injection engines although they’re still DI but the piston crown’s slightly different to compensate,” explains Steve.   The important thing however is – as with all DI engines – the ports are dry, therefore, no fuel flows around the backs of the valves at all. One of the major factors of DI engines is that they run ultra-lean, which obviously is driven by emissions – they are therefore extremely efficient and in so being they have a lot capacity for extra performance – which of course is where SBD score so highly.

 

Injectors

DI injectors are unique to the particular engine they are fitted to – they’re extremely high pressure but their characteristics are centred around the nozzle pattern.  Indeed, their flow rate may well be identical to other injectors of the same series but importantly, they won’t work simply because of that nozzle pattern, itself designed to work with the shape of the piston’s crown – basically they’re matched and work as a pair. In these engines, injectors are incredibly expensive components so the goal is to optimise them to work with other components – or, as we’ll see later fit more injectors.

 

 

Turbo

The ethos behind power delivery is more towards city driving; where power’s needed from tick-over.  As such, the standard turbo produces its maximum around 2000 rpm at 1.25 BAR of boost. However, it’s over-engineered so there’s more in there than Ford’s 160bhp standard engines produce.  It takes a special series of management – as we’ll see – but Steve reports that with an ECU change, SBD have rung 227bhp from the engine using the standard turbo.  He went on to explain that Ford’s plan is to use the one-turbo-fits-all idea to manage production costs; meaning that the sporty versions using this EcoBoost will only need a change of ECU – which of course SBD have taken advantage of. Further SBD’s performance has come in-conjunction with Turbo Technics who has produced various hybrid turbos to reach 301bhp and 308lbft – although the limit at the moment’s governed by the injectors running out of flow.

 

Variable Cam Timing

The variable valve timing (VVT) is a major part of the whole package. We’ll examine the port shape later but it’s probably one of the major areas that highlights the necessity for VVT – working via oil control in-conjunction with ECU management.  The 1.6 features the ability to move both inlet and exhaust cams to optimise timing; not just for supreme emissions control but also so the engine will simply work and the car drive well using almost extremes of other components and design. As in other engines, the cams will move within a window of 60 degrees of advance or retard and will around almost wildly, controlled by the ECU for performance economy. Using VVT, both the inlet and exhaust cams adjust to optimise timing.

 

Auxiliary Fuel Pump

Within the fuel tank there is an in-tank high-pressure pump, negating the need for a separate lift and swirl pot system.  This however, interacts with another pump on the top of the cylinder head, driven by the exhaust cam. This is complemented by the fuel rail varying the fuel pressure, although not the quantity of fuel. If necessary, this system has the ability to pulse the fuel delivery with the minute – millisecond-windows that the fuel injector has in which to accurately deliver its fuel. Timing is therefore absolutely crucial and needs a very high-tech ECU to cope.  all this adds to the lean-burn characteristics of the engine; seriously controlling emissions but supplying such superb horsepower figures too.

 

 

Cylinder head

1. This uses 16-valves controlled by twin camshafts using mechanical lifters precisely machined to extremely high tolerances. Although it has a similar physical pattern, the head is completely different to the Sigma engine that this particular EcoBoost is derived from. Contrary to popular belief, the 1600 EcoBoost’s cylinder head isn’t a development of the Sigmas version.

2. The cams are a typical turbo pattern with no overlap to promote good emissions – this means injector timing is critical as there’s only a small window when both valves are shut.  The cams aren’t exactly the same since the exhaust has a drive to run the high-pressure fuel pump.

3. The ports follow performance bike engine design.  The slope at an acute angle.  The typically produces a peaky rev band – with the addition of VVT however, the engine is now far more drivable as the cam timing can be moved around to take full advantage of the design.

4. The combustion chambers house four-valves – 30mm inlet and 25mm exhaust.  It’s a DI engine so as well as the normal spark plug position in addition, right in the centre is the housing for the fuel injector, which fires directly onto the crown of the piston. 

 

Coil-on-plug

Naturally the engines feature crank trigger ignition, controlled by the ECU and features individual coils on each plug.

 

Sump

1. This is reasonably low profile but doesn’t have any cut-outs that could interact with the crossmember of a classic Ford – there’s no front or rear-bowl sump to contend with.

2. SBD already make a dry sump system, which consists of an ultra-low profile sump pan, plus an external oil pump.

 

Bottom End

The main components of the 1.6 EcoBoost are extremely similar to the Sigma engine it’s based on – the block is aluminium with the crank sitting up inside the block, braced by a cast steel cradle. The rotating mass is designed to have a little impingement on oil return as necessary – in addition the oil return is via external channels meaning there’s no splashing to potentially slow the crank as it drops back in the sump.

 

Con-rods

SBD haven’t had cause to change the standard rods yet, but they are similar to the 1-litre con-rods, which follow late Ford engine pattern, being of a chunky I-beam sintered construction. True to form, they feature laser-scored then control-broken big end caps, which mean they only fit the rod they were broken from and therefore reduce production processes cutting costs. As this is a turbo engine, the rods are not required to rev excessively, therefore the construction and materials don’t have to be of the very best quality to cope.

 

Pistons

1. Typical of EcoBoost engines, these are cast alloy and of classic low-bodied, slipper design. The all-important part is the shape of the domed crowns, which interact with the injectors to produce as efficient a burn as possible. The compression ratio is 10:1 – high for a turbo engine but the lean-burn characteristics and serious engine management control means they can be run far tighter compared to a traditional engine.

2. So far SBD have not reached the limited of the pistons but Steve reckons it’s around 350bhp. They have produced a prototype forged piston for use when this is reached – they feature an altered stroke by moving the gudgeon pin up into the body, while there’s a system of grooves around the top edge, designed to control combustion pressure.

3. Steel rods have specced to SBD’s design. Note the cutaway tops of the small ends, which reduces weight – these are turbo engine, where the thrust is more on the bottom section of the small end allowing the top to be cut away and not lose any strength. Because of the top of the small end is narrower, this allows the piston to taper towards the crown increasing strength for both standard and uprated piston designs.

 

Ancillaries

1. The thermostat housing is built into the side of the engine – shown on this engine is a plastic unit derived from the Sigma. There’s no reason to sue this other than it fit SBD’s installation better.

2. The EcoBoost thermostat is this metal unit, beneath which is housed the normal Ford twin-ended thermostat, and serves to circulate hot water when the engine’s cold to quickly reach operating temperature, at which time, it diverts to the normal thermostat through the cooling system.

3. SBD plan to make a water rail which will direct coolant on the opposite side for use with a Laminova oil cooler. The rail will also reduce protrusion at the rear, aiding rear-drive fitment. SBD intend to run without a thermostat preferring to use an ECU-controlled electric water pump instead. 

 

 

Classic Ford Adaption

The Sigma has already been turned around to rear-drive and there’s a bellhousing to bolt a Type-9 behind it. The bolt pattern is the same on the 1.6 EcoBoost – although its torque will annihilate all but the very strongest straight-cut ‘box of the same type. Steve’s own cars will use a Sadev six-speed sequential, which is a massive amount of money. No doubt the inventive will investigate the fact you can already buy a laser-cut adapter to mount a Mazda RX8 ‘box behind the engine.

 

More Power

So far, extra power has been achieved using a new MBE9A6 management system, which uses CAN BUS rather than a traditional motorsport ECU, which makes use of serial port. The DI system is that complex that only a specifically tailored ECU will handle it. Everything is variable with these engines – obviously cam time, but also fuel, injector pressure even gearbox torque control. It is a fly by wire system, has knock control, launch control, tractions; virtually everything; justifying the £2700. A Raychem military spec harness is priced at £1560. The ECU comes fully programmed for either the standard engine or any of SBD’s upgrade kits meaning there’s no need for additional programming.

 

There’s obviously a limit to the injectors and their nature is that they are prohibitively expensive to replace – easier is the system that’s currently in development to produce a new alloy plenum which bolts on in place of the current plastic inlet. This will house a second set of injectors to complement the originals allowing the extra amount of fuel that will be necessary to achieve the 350bhp ceiling, without component changes. The original throttle body is currently utilised and bolts on the end of the housing. SBD are already developing an upgraded piston, rod, crankshaft and other internal components to maintain the reliability and push the performance to hopefully over 400bhp.

 

SBD’s main plan is to produce the most powerful 1.6 EcoBoost with virtually no lag, so it drives as if normally-aspirated and achieve the maximum horsepower possible, it may be possible to achieve a lot more horsepower but it wouldn’t be any good for normal motorsport use, only for the drag strip when lag and durability are not the most important thing.

 

Feature reproduced with permission from Classic Ford Magazine