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The Ford Sigma is a small straight-4 automobile engine introduced in 1995 by Ford Motor Company. Its first evolution was sold as the Zetec-S (not to be confused with the trim level), then Zetec-SE and finally, in later years, renamed Duratec.[3] The last upgrade of the engine is named Duratec Ti-VCT. Conceived for Ford's smaller models, the engine was intended to replace the older HCS (a derivative of the even older Kent unit) and smaller capacity CVH units.

Ford logo.svg Sigma engine
Ford Zetec-S 1.6 16V engine.jpg
Overview
ManufacturerFord Motor Company, Yamaha Motor Company[1][2]
Also calledZetec-S
Zetec-SE
Duratec
Duratec Ti-VCT
Production1995-
Layout
ConfigurationStraight-4
Displacement1.2 L; 75.8 cu in (1,242 cc)
1.4 L; 84.7 cu in (1,388 cc)
1.5 L; 91.5 cu in (1,499 cc)
1.6 L; 97.4 cu in (1,596 cc)
1.7 L; 102.5 cu in (1,679 cc)
Cylinder bore71.9 mm (2.83 in)
76 mm (2.99 in)
79 mm (3.11 in)
80 mm (3.15 in)
Piston stroke76.5 mm (3.01 in)
81.4 mm (3.20 in)
83.5 mm (3.29 in)
Block materialaluminium
Head materialaluminium
ValvetrainSOHC 2 valves x cyl.
DOHC 4 valves x cyl. w/Ti-VCT
Compression ratio10.0:1, 10.3:1, 11.0:1, 11.8:1
Combustion
SuperchargerOn 2002 1.0–litre Ford Fiesta
Fuel systemElectronic fuel injection
Sequential multi-port FI
ManagementPCM, Siemens
Fuel typegasoline
Oil systemPressure-fed with full flow oil filter
Cooling systemWater-cooled
Output
Power output75–155 PS (55–114 kW; 74–153 hp)
Torque output110–162 N⋅m (81–119 lb⋅ft)
Dimensions
Dry weight1.6 L Zetec - 81 kg (179 lb)
1.6 L Duratec - 90 kg (198 lb)
Emissions
Emissions target standardEuro 4, Euro 5
Emissions control technologyClose-coupled, closed loop, three-way catalyst with oxygen sensor
Chronology
PredecessorFord CVH engine
Ford Kent engine
SuccessorFord EcoBoost engine

Contents

Introduction and productionEdit

As with the Ford Taurus SHO's SHO V6 engine, development of the Zetec-SE was a collaborative effort between Ford and Yamaha.[1][2] The engine's sounds were refined in the Ford acoustics center in Cologne-Merkenich, Germany.[1] Production of the Zetec-SE was carried out in the Ford Valencia Engine Plant, with Yamaha applying a Nikasil coating to the 1.7 L engines in Japan.[1][2]

When the Zetec-SE first arrived in 1995, it included many firsts, such as a plastic inlet manifold, a "ladder" style main bearing and crankcase assembly, and big-end bearing caps which are forged in one piece and subsequently split. It also incorporates powder metal connecting rods, which were quite exotic and notable at the time. The engine first appeared in the Mk4 Ford Fiesta and the virtually identical Mazda 121 in 1.2 L (1,242 cc) capacity, with 1.4 L (1,388 cc), 1.6 L (1,596 cc) and 1.7 L (1,679 cc) derivatives coming later.

Difference between Zetec-SE/Zetec-S/Duratec/Duratec Ti-VCTEdit

The Sigma engined was introduced under the Zetec-SE name; after the upgrade it was renamed to Duratec. The latest upgrade of Sigma is called Duratec Ti-VCT.

Zetec-S/SEEdit

Code Years Displacement Bore x stroke Power@rpm Torque@rpm Compression
1.25 Zetec-S/SE 1995- 1.2 L; 75.8 cu in (1,242 cc) 71.9 mm × 76.5 mm (2.83 in × 3.01 in) 75 PS (55 kW; 74 hp)@5200 110 N⋅m (81 lb⋅ft)@4000 10.0:1
1.4 Zetec-S/SE 1998- 1.4 L; 84.7 cu in (1,388 cc) 76 mm × 76.5 mm (2.99 in × 3.01 in) 75 PS (55 kW; 74 hp)@5000 124 N⋅m (91 lb⋅ft)@3500 11.0:1
1995- 90 PS (66 kW; 89 hp)@5500 123 N⋅m (91 lb⋅ft)@4000 10.3:1
1.6 Zetec-S/SE 1998- 1.6 L; 97.4 cu in (1,596 cc) 79 mm × 81.4 mm (3.11 in × 3.20 in) 100 PS (74 kW; 99 hp)@6000 145 N⋅m (107 lb⋅ft)@4000 11.0:1

Zetec-SEdit

1.7 Zetec-S VCT 1997- 1.7 L; 102.5 cu in (1,679 cc) 80 mm × 83.5 mm (3.15 in × 3.29 in) 126 PS (93 kW; 124 hp)@6300 157 N⋅m (116 lb⋅ft)@4500 10.3:1
1999- 155 PS (114 kW; 153 hp)@7000 162 N⋅m (119 lb⋅ft)@4500

The 1.7 L; 102.5 cu in (1,679 cc) engines uses a heavily modified 1.6 L engine block and features Variable Cam Timing on the inlet camshaft. This displacement has only been used in Ford Puma. 155 PS (114 kW; 153 hp) engine has only been used for the Ford Racing Puma with only 500 units built.

Zetec RoCamEdit

In 2000, Ford of Brazil developed a cheaper version of the Zetec-SE engine, to compete with the classic Volkswagen EA827 engine series known locally as AP (from "Alta Performance", "High Performance", in English) engine in Brazil. It is 8v SOHC instead of 16v DOHC and its block is made of iron instead of aluminum. Also, its camshaft is driven by a chain instead of a belt. As a result this engine exhibits rougher behaviour, producing more vibration and noise.

On the other hand, it has a superb torque output thanks to the addition of the RoCam (Rollifinger Camshaft) feature. It's also a much smaller engine than the SE version, which allowed it to be installed on the Ford Ka, replacing the Endura-E engine which by that time was considered underpowered and outdated.

The engine also featured a new patented process for the aluminum head production, which resulted in a better alloy than those produced in Spain and UK, and at a lower production cost.

In 2002 a supercharged 1.0–litre 95 PS (70 kW; 94 hp) version was released for the Ford Fiesta, to compete with the 1.0 Turbo 16v 112 PS (82 kW; 110 hp) version of the Volkswagen Gol.

In 2003 the Zetec RoCam engine was introduced in Europe, but labeled as Duratec 8v, for the SportKa, StreetKa and Fiesta. Later a 1.3–litre version was also released as an option for the standard model, but the European versions of the engine are produced in the South Africa plant.

In October/2004 a newer bi-fuel version was introduced labeled "1.6L Flex", capable of running on both petrol and ethanol, even mixed at any proportion. This version also featured a high compression ratio of 11.8:1 and "Compound High Turbulence" chambers, as used on the CHT engine.

Currently, this engine powers nearly all Brazilian Ford models – except those with 2.0 litre engines – in many different variants:

ApplicationsEdit

1.6 or 1.6 L; 97.4 or 97.5 cu in (1,596 or 1,597 cc) applications:

  • –present Latin America Ford SportsKa 1.6, 95 PS (70 kW; 94 hp) and 100 lb⋅ft (136 N⋅m)
  • –present Latin America Ford StreetKa 1.6, 95 PS (70 kW; 94 hp) and 100 lb⋅ft (136 N⋅m)

DuratecEdit

Ford upgraded Sigma and renamed it to Duratec.

Code Years Displacement Bore x stroke Power Torque Compression
1.25 Duratec 2008- 1.2 L; 75.8 cu in (1,242 cc) 71.9 mm × 76.5 mm (2.83 in × 3.01 in) 60 PS (44 kW; 59 hp) 109 N⋅m (80 lb⋅ft) 11.0:1
80 PS (59 kW; 79 hp) 114 N⋅m (84 lb⋅ft)
1.4 Duratec 2002- 1.4 L; 84.7 cu in (1,388 cc) 76 mm × 76.5 mm (2.99 in × 3.01 in) 80 PS (59 kW; 79 hp) @ 5700 124 N⋅m (91 lb⋅ft) @ 3500
2008- 96 PS (71 kW; 95 hp) 125 N⋅m (92 lb⋅ft)
1.6 Duratec 2004- 1.6 L; 97.4 cu in (1,596 cc) 79 mm × 81.4 mm (3.11 in × 3.20 in) 100 PS (74 kW; 99 hp) @ 6000 150 N⋅m (111 lb⋅ft) @ 4000

Duratec Ti-VCTEdit

The 1.6 L; 97.4 cu in (1,596 cc) Ti-VCT (Twin independent Variable Camshaft Timing) version includes variable valve timing, and generates more power and torque than non-VVT counterparts. Latest versions comply with the Euro5 emission level.

Code Years Displacement Bore x stroke Power Torque Compression
1.5 Duratec Ti-VCT 2013- 1.5 L; 91.5 cu in (1,499 cc) 79 mm × 76.5 mm (3.11 in × 3.01 in) 112 PS (82 kW; 110 hp) @ 6300 140 N⋅m (103 lb⋅ft) @ 4300 11.0:1
1.6 Duratec Ti-VCT 2004- 1.6 L; 97.4 cu in (1,596 cc) 79 mm × 81.4 mm (3.11 in × 3.20 in) 115 PS (85 kW; 113 hp) @ 6000 155 N⋅m (114 lb⋅ft) @ 4150
2007- 110 PS (81 kW; 108 hp) @ 6000 152 N⋅m (112 lb⋅ft) @ 4050
125 PS (92 kW; 123 hp) @ 6300 160 N⋅m (118 lb⋅ft) @ 4100
2008- 120 PS (88 kW; 118 hp) @ 6300
2010- 105 PS (77 kW; 104 hp) @ 6000 150 N⋅m (111 lb⋅ft) @ 4000-4500
2011- 134 PS (99 kW; 132 hp) @ 6700 160 N⋅m (118 lb⋅ft) @ 4250

Crate engine versionsEdit

Crate engine versions of Zetec-SE engines are sold by Ford Power Products under the name ZSG Range.

Code Years Displacement Bore x stroke Power@rpm torque@rpm Compression
ZSG 414 ?- 1.4 L; 84.7 cu in (1,388 cc) 76 mm × 76.5 mm (2.99 in × 3.01 in) 75 PS (55 kW; 74 hp)@5700 124 N⋅m (91 lb⋅ft)@3500 11.0:1
ZSG 416 1.6 L; 97.3 cu in (1,595 cc) 79 mm × 81.4 mm (3.11 in × 3.20 in) 100 PS (74 kW; 99 hp)@6000 146 N⋅m (108 lb⋅ft)@4000

ApplicationsEdit

Displacement ratings vehicles
1.2 L; 75.8 cu in (1,242 cc) 60 PS (44 kW; 59 hp), 109 N⋅m (80 lb⋅ft)
75 PS (55 kW; 74 hp)@6000, 110 N⋅m (81 lb⋅ft)@4000
80 PS (59 kW; 79 hp), 114 N⋅m (84 lb⋅ft)
1.4 L; 84.7 cu in (1,388 cc) 75 PS (55 kW; 74 hp), 124 N⋅m (91 lb⋅ft)
80 PS (59 kW; 79 hp)@5700, 124 N⋅m (91 lb⋅ft)@3500
90 PS (66 kW; 89 hp), 125 N⋅m (92 lb⋅ft)
96 PS (71 kW; 95 hp), 125 N⋅m (92 lb⋅ft)
1.5 L; 91.5 cu in (1,499 cc) (with Ti-VCT) 112 PS (82 kW; 110 hp), 140 N⋅m (103 lb⋅ft)
1.6 L; 97.4 cu in (1,596 cc) 100 PS (74 kW; 99 hp)@6000, 145 N⋅m (107 lb⋅ft)@4000
100 PS (74 kW; 99 hp)@6000, 150 N⋅m (111 lb⋅ft)@4000
1.6 L; 97.4 cu in (1,596 cc) (with Ti-VCT) 115 PS (85 kW; 113 hp)@6000, 155 N⋅m (114 lb⋅ft)@4150
120 PS (88 kW; 118 hp)@6000, 152 N⋅m (112 lb⋅ft)@4050
105 PS (77 kW; 104 hp)@6000, 150 N⋅m (111 lb⋅ft)@4000-4500
110 PS (81 kW; 108 hp)@6300, 160 N⋅m (118 lb⋅ft)@4100
125 PS (92 kW; 123 hp)@6000, 159 N⋅m (117 lb⋅ft)@4000
1.7 L; 102.5 cu in (1,679 cc) (with VCT) 126 PS (93 kW; 124 hp)@6300, 157 N⋅m (116 lb⋅ft)@4500
155 PS (114 kW; 153 hp)@7000, 162 N⋅m (119 lb⋅ft)@4500
  • 1999-2000 Ford Racing Puma 1.7

Current useEdit

The Ford Sigma engine is produced at Bridgend Ford in Wales, U.K. and at Taubate Engine & Transmission Plant, Taubate, São Paulom, Brazil. Today Sigma engines are used by Focus, Fiesta, C-Max and Mondeo. A 110 bhp (82 kW; 112 PS) version is used by Morgan for their 4/4 Roadster since 2009, albeit coupled to a Mazda transmission driving the rear wheels.[4]

1.25/1.4/1.6 L SigmaEdit

These engines in the first generation Focus produced 75 and 100 bhp (75 kW; 101 PS) respectively, but for MkII Focus the 1.4 variant was slightly modified and produced 80 bhp (60 kW; 81 PS). Both engines have belt driven camshafts and Electronic Fuel Injection systems. They weigh 90 kg (198 lb).[1] [2] The 1.6 Ti-VCT was introduced in 2004, it features Variable Cam Timing; this 115 bhp (86 kW; 117 PS) version is used in MkII Focus. A new 105 bhp (78 kW; 106 PS)/125 bhp (93 kW; 127 PS) EU5 version is used in the MkIII Focus, also a 1.6 L 120 hp (89 kW; 122 PS) version is used in Ford Fiesta Zetec-S. The Sigma is usually coupled to the Ford IB5 five-speed manual transmission.

BrazilEdit

Recently the Sigma engine was present in modern Brazilian versions of the Fiesta, Focus and Ecosport (1.6L TI-VCT version) and a 1.5 version was used by Ka. This engine was able to use the flex technology.

Power with ethanol:

  • 1.5L Sigma (non TI-VCT) - IB5+ manual transmission
    • Fiesta (2014-2016) - 112 PS (82 kW; 110 hp)
    • Ka (2014-Present) - 110 PS (81 kW; 108 hp)
  • 1.6 Sigma (non TI-VCT) - IB5+ manual transmission (both) and PowerShift (Fiesta Only).
    • Fiesta (2008-2014) - 116 PS (85 kW; 114 hp)
    • Ecosport (2012-Present) - 116 PS (85 kW; 114 hp)
  • 1.6 Sigma TI-VCT - IB5+ manual transmission and PowerShift.
    • Focus (2013-Present) - 135 PS (99 kW; 133 hp)
    • Fiesta (2008-2014) - 128 PS (94 kW; 126 hp)
    • Ecosport (2012-Present) - 131 PS (96 kW; 129 hp)


  • In 2018 the Sigma engine was replaced in all Ford compact/subcompact cars to the newer and stronger "Dragon" engine, displacing 1.5L with a 3-Cylinder layout and with a power output of 136HP.

Caterham usageEdit

Some Caterham Cars use modified Ford Sigma engines[5] such as the Caterham Seven 270, which uses a tuned Sigma engine producing 135 hp (101 kW; 137 PS) at 6,800 rpm as a modern equivalent to the original Ford Kent Crossflow engine used in the Lotus 7 from 1957 to 1972.
Ford Sigma 1.6-litre overview Technical features:

  • a high level of running refinement and low emission levels
  • aluminium alloy cylinder block and head
  • cross flow cylinder head
  • structural aluminium oil-pan for increased engine stiffness
  • individual throttle bodies in place of the standard intake manifold
  • twin overhead camshafts each with five bearings
  • sequential multi-port fuel injection system
  • long life, glass fibre reinforced camshaft drive belt with automatic tensioner
  • state-of-the-art Twin Independent Variable Camshaft Timing (on Ti-VCT variant)
Code Displacement Bore x stroke Power@rpm torque@rpm Compression
Ford Sigma 1.6 1.6 L; 97.3 cu in (1,595 cc) 79 mm × 81.4 mm (3.11 in × 3.20 in)? 125 PS (92 kW; 123 hp)@6100 162 N⋅m (119 lb⋅ft)@5350 11.0:1
150 PS (110 kW; 148 hp)@6900 162 N⋅m (119 lb⋅ft)@5600
Caterham Sigma 1.6 Ti-VCT EU4 115 PS (85 kW; 113 hp)@6000 155 N⋅m (114 lb⋅ft)@4150

SCCA Spec RacerEdit

The third generation of the SCCA Spec Racer, commonly known as the Gen3 was introduced in 2015,[6] and uses the 1.6 L Sigma engine. The engine is sold by SCCA Enterprises as a sealed unit.

Zetec-E comparisonEdit

The Zetec-SE has no common parts or design with the larger Zetec-E engines apart from the name. This gives rise to some confusion since it suggests that they are members of the same family when they are, in fact, completely different. Zetec-E units are mounted transversely with the inlet manifold at the rear, whereas the Zetec-SE units are mounted with the inlet manifold at the front.

ReplacementEdit

In 2012 Ford replaced the Sigma engine with a brand new 3-cylinder 1.0–litre EcoBoost engine for some markets and models. The new engine provides more power and torque with less fuel consumption and less CO
2
emissions.[7]

See alsoEdit

ReferencesEdit

  1. ^ a b c d Binon, Pascal (March 16, 1996). "Un moteur Zetec léger, original et au bruit raffiné". Le Soir. Archived from the original on 2019-03-17.
  2. ^ a b c Lewin, Tony (July 7, 1997). "Yamaha coats cylinders for Ford Puma". Automotive News. Archived from the original on 2019-03-17.
  3. ^ Fuel, performance and emissions Ford Fiesta, Ford.co.uk, 21 April 2009.
  4. ^ "4/4: Specifications". The Morgan Motor Company. Retrieved 2013-06-05.
  5. ^ caterhamcars.com
  6. ^ "Spec Racer Ford". SCCA Enterprises. Retrieved 2016-11-12.
  7. ^ Ecoboost replaces Duratec, themotorreport.com.au, 05. February 2012.

External linksEdit