Duratec Discovery

There's a wide range of Duratec engines - and an even wider range of car companies calling them their own... Let's take a look at all the details.

Duratec V6s

The first Duratec engine put into production in 1994 was an all-alloy 60-degree V6. Displacing 2544cc (using an 82.4mm bore and 79.5mm stroke) the ‘Duratec 25’ features a pair of DOHC, four-valve-per-cylinder heads and a fixed-length aluminium intake manifold. The engine was considered one of the best of its era and was included in the Ward’s 10 Best Engines list for 1995 and 1996.

Available as an option in the 1994 Ford Mondeo (but only in some countries), this engine generates 127kW. The Duratec 25 was also fitted to other US/UK market Ford vehicles.

An updated version of the Duratec 25 appeared in the second generation Mondeo which was released in 1997. Despite swept capacity being reduced from 2544 to 2495cc, the new engine maintains a 127kW maximum output. This engine is widely known as the Duratec VE. In Australia, this engine can be found in the Mondeo ST24 and Cougar.

A high-performance version of the Duratec 25 was developed for the 1998 to 2000 US-spec Ford Contour SVT. This engine uses upgrade camshafts, a larger throttle body, conical air filter and abrasive honed intake manifold, free-flow exhaust and lightweight flywheel. Output is a substantial 145kW and 224Nm – not bad for a naturally aspirated 2.5-litre! Minor updates in 1999 achieve another 4kW and 5Nm.

Interestingly, Mazda picked up the Duratec 25 block and adapted it for use in the 2000-2002 MPV people mover. In MPV guise, we believe the engine uses the late-model small diameter bore. This shrinks cubic capacity to just under 2.5 litres and avoids a higher tax bracket in the Japanese domestic market. It appears that the Mazda engine also receives variable inlet cam timing to help achieve 129kW and 227Nm of torque.

Interestingly, the Jaguar S-Type and X-Type are also powered by an engine which is essentially a Ford Duratec. The 2.5 litre version (dubbed AJ25) uses the same bore and stroke dimensions as the Mazda and receives variable inlet cam timing. With a higher compression ratio and some other changes, output is 145kW and 244Nm.

Curiously, a little 2.1-litre version of the V6 was also introduced in the Jaguar X-Type. This engine makes only 117kW.

A ‘big banger’ version of the Duratec V6 was released in 1996 – the Duratec 30. By enlarging the V6’s bore diameter to 88.9mm, total swept capacity increases to 2967cc. The earliest version of this engine – dubbed the Duratec 30 RFF – uses roller finger followers and produces 150kW at 5000 rpm and 281Nm at 4400 rpm - substantial gains over the base Duratec 25.

The 3 litre engine was fitted to the Ford Taurus/Mercury Sable from 1996, Ford Escape/Mazda Tribute from 2001 and various US-spec Ford/Mercury vehicles. From 2006, we believe selected Ford, Mercury and Lincoln models were updated with variable valve timing. This helps increase output to 165kW and 278Nm.

In the UK Ford Mondeo range you’ll find a 152kW version of the 3 litre Duratec V6 but more interesting is the tuned 3-litre found in the ’02 Mondeo ST220. The ST220 engine features a free-flow exhaust and air intake to help generate 162kW (220ps) and 275Nm. The ST220 is a favourite performance car in the UK.

Mazda also adopted the 3-litre V6 as its own for use in the 2000 – 2004 MPV and 2005 Mazda 6 (which is available with a V6 in some counties). With variable cam timing and a roller finger follower valvetrain, this engine generates 147kW at 6200 rpm and 271Nm at 3000 rpm.

A slightly different version, which uses direct-acting mechanical bucket tappets, can be found in the more upmarket Jaguar S-Type and X-Type. Again using variable inlet cam timing and a higher compression ratio, the Jaguar version puts out up to 179kW and 300Nm.

We believe that an even bigger 3.5-litre version of the Duratec is also about to be put into production for ’07 model year vehicles.

Duratec Fours

The worldwide lineage of the four-cylinder Duratec is difficult to follow but it appears that when the 2000 Mondeo was introduced, the existing Zeta four-cylinder engine was renamed Duratec. Today, all European Ford engines are dubbed Duratec. However in the US, the name is applied to only DOHC four and six-cylinder engines...

A 1.8 and 2-litre version of the Duratec four was fitted in the ’00 Mondeo with an output up to 108kW. These engines were also spread into the Focus range and, when released locally in ‘02, outputs were 85 and 96kW respectively.

One of the most popular Duratec engines at present is the 1.6-litre engine found in the post ’03 Fiesta. This willing little slogger employs electronic throttle control and maxes out at 74kW/146Nm.

Although based on the Zetec engine, the hottest naturally aspirated Duratec four can be found in the Focus ST170 (known as the Focus SVT in some counties). This engine boasts hot cams, a higher compression ratio, an improved head, dual-stage intake manifold and free-flowing intake and exhaust systems. The result is 127kW at a high 7000 rpm along with 196Nm at 5500 rpm.

We believe that a single turbocharged version of the Duratec 2-litre four was also available in the Focus RS sold in some counties. The turbocharged engines offers much greater torque and around 160kW of top-end power.

A big 2.3-litre version - the Duratec 23 - is also available. Using a unique bore and stroke combination (87.4 and 94mm respectively), the Duratec 23 displaces 2261cc. Output is around 110 – 120kW depending on the vehicle and marketplace. Mazda versions are typically at the upper end of this range.

A slightly less powerful (107kW) version is also available in the Ford Ranger, Mazda B-series and Ford Escape/Mazda Tribute.

Least exciting in the range is the Duratec 8-valve which, in its base grade, is a 1.3-litre engine with an OHV (!) valvetrain. This engine puts out a miserly 43kW and 100Nm and can be found in the Ford Ka. A more upmarket SOHC version of the 1.3 can be found in the ’03 UK-spec Ford Fiesta. This engine makes a more creditable 51kW but the pick of the Duratec 8V engines is the larger 1.6-litre available in the Fiesta. This engine makes 70kW – still nothing to get excited about...

Duratec Based V8s

In the US market, the 1996 to 1999 Ford Taurus was offered in SHO (Super High Output) form which brought a 3.4-litre V8. Interestingly, this engine was jointly developed with Yamaha but it employs several Duratec V6 components – for example, its bore and stroke dimensions are identical. The V8 uses a dual-stage intake system that helps achieve 175kW and 312Nm. Unfortunately, this engine was hampered by camshaft related reliability problems.

There is also rumour that the Duratec based V8 is now used - in extensively modified form – under the bonnet of the Volvo XC90. With displacement increased to 4.4-litres, the XC90 engine puts out 232kW/441Nm. Note that this is one of the few V8 engines which is designed for transverse mounting. It also uses 60-degree opposed cylinder banks – a sure indication that the Duratec V6 is hiding beneath it all...