The Ford I4 DOHC engine is a cast iron block 4-cylinder inline

internal combustion engine An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal c ...

with twin overhead camshafts, produced by the

Ford Motor Company Ford Motor Company (commonly known as Ford) is an American multinational automobile manufacturer headquartered in Dearborn, Michigan, United States. It was founded by Henry Ford and incorporated on June 16, 1903. The company sells automobi ...

at Dagenham Engine Plant. It was initially available as a 2.0 litre 8-valve version, and later in 2.0 and 2.3 litre 16-valve versions from 1989 to the end of production of the MK2

Ford Galaxy The Ford Galaxy is a seven-seater car produced by Ford of Europe from June 1995 to April 2023. Considered in the motor industry to be a large multi-purpose vehicle (MPV), it was the first Ford-brand MPV produced and marketed outside of North Ame ...

in 2006. It powered various Ford models during this time, but was most well known in the rear-wheel drive "Twin Cam" variants of the

Ford Sierra The Ford Sierra is a mid-size car or large family car manufactured and marketed by Ford Europe from 1982-1993, designed by Uwe Bahnsen, Robert Lutz and Patrick le Quément — and noted for its aerodynamic styling producing a drag coeffi ...

and

Ford Scorpio The Ford Scorpio is an executive car that was produced by Ford Europe from 1985 to 1998. It was the replacement for the European Ford Granada line (although in the UK and Ireland the Scorpio was marketed under the Granada name until 1994). Li ...

. Despite being built for the company's larger RWD models, Ford also employed the engine in the front-wheel drive Galaxy and the Escort RS 2000 16v.

History

The engine was originally designed to replace the 2.0 L OHC Pinto engine, derivatives of which had powered most of Ford's four-cylinder rear-wheel drive cars since the early 1970s, and which was by that time lagging behind the competition in terms of power output, efficiency and refinement. Equipped with a newly designed cast aluminium alloy twin-cam cylinder head but still only 8 valves, and a "square" bore and stroke, the new I4 was launched in the

and Scorpio, mated to either the also new all-synchromesh MT-75 5-speed

manual transmission A manual transmission (MT), also known as manual gearbox, standard transmission (in Canada, the United Kingdom, and the United States), or stick shift (in the United States), is a multi-speed motor vehicle transmission system, where gear change ...

or the existing A4LD four-speed automatic. The engine received mixed reviews, being seen as an improvement over the Pinto, but not the leap forward one might have expected.

Transverse installation

Although front-wheel drive and already powered by a separate range of engines, the Escort received the next major incarnation of the I4. In 1990, the MkV Escort had been launched to disappointing press reviews, and Ford were looking to boost the image of this critically important range and steal sales from arch rivals Vauxhall and VW who were doing very well with big bore GTE/GTI badged versions of their family hatches. Ford's strategy was to introduce two high-performance versions of the Escort to compete in the

hot hatch A hot hatch (shortened from hot hatchback) is a high-performance hatchback car. The term originated in the mid-1980s; however, factory high-performance versions of hatchbacks have been produced since the 1970s. Front-mounted petrol engines, ...

market, using the well known XR3i and

RS2000 The Ford Escort is a small family car that was manufactured by Ford of Europe from 1968 until 2000. In total there were six generations, spread across three basic platforms beginning with the original rear-wheel drive Mk.1/Mk.2 (1968–1980) ...

badges. The

Zetec Ford Motor Company used the Zetec name on a variety of inline 4-cylinder automobile engines. It was coined to replace "Zeta" on a range of 1.6 L to 2.0 L multi-valve engines introduced in 1991 because Ford was threatened with legal acti ...

engine being developed for the new Mondeo was a still a year away, so rather than wait for the new engine to become available Ford opted to use this engine with a new multivalve cylinder head and tubular exhaust manifold, and mount it transversely in a FWD application. With the discontinuation of the Sierra in 1993 and the RS2000 in 1996, the I4 engine continued in more workaday applications, appearing in the

MPV launched in 1995. By this time, a longer-stroked 2.3 litre 16-valve version of the engine was available alongside the original 2.0 which was still available in both 8-valve and 16-valve versions. This 2.3 litre unit also appeared in the

and the Ford Transit van. The I4 remained the main petrol unit for the original Galaxy until its 2006 redesign.

8v engine Specifications

* Two

valve A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fitting ...

s per cylinder with hydraulic valve lifters * Twin camshafts driving by a

timing chain In a piston engine, either a timing belt (also called a ''cambelt'') or timing chain or set of timing gears is used to synchronize the rotation of the crankshaft and the camshaft. This synchronisation ensures that the engine's valves open and cl ...

* Stroke and bore were both * Compression was 10.3:1 (Later versions of the 8V DOHC were 9.8:1) * Five main crankshaft bearings

N8A

Carbureted A carburetor (also spelled carburettor) is a device used by an internal combustion engine to control and mix air and fuel entering the engine. The primary method of adding fuel to the intake air is through the venturi tube in the main meteri ...

* Power: at 5600 rpm. * Torque: at 3000 rpm. * Redline: 6050 rpm

N9A

Electronic fuel injection Manifold injection is a mixture formation system for internal combustion engines with external mixture formation. It is commonly used in engines with spark ignition that use petrol as fuel, such as the Otto engine, and the Wankel engine. In a mani ...

(Batched multi-point) * Power: at 5500 rpm. * Torque: at 2500 rpm. * Redline: 5950 rpm
Maximum continuous engine speed: 5950rpm

N9C/N9E/NSE/N9D

* Electronic fuel injection (Batched multi-point) (N9x with EEC4, NSx with EEC5 istributor-less *

Catalytic converter A catalytic converter is an vehicle emissions control, exhaust emission control device that converts toxic gases and pollutants in exhaust gas from an internal combustion engine into less-toxic pollutants by catalysis, catalyzing a redox chemic ...

* Power: at 5500 rpm * Torque: at 2500 rpm. * Redline: 5950 rpm

16-valve engines

N7A

* Capacity: * Bore x Stroke: * Compression: 10.3:1 * Valvegear: Chain driven DOHC. 16 valves. Hydraulic tappets. * Fuelling: EEC-IV controlled multi-point fuel injection * Power: @ 6000 rpm * Torque: @ 4500 rpm

N3A

* Capacity: * Bore x Stroke: * Compression: 9.8:1 * Valvegear: Chain driven DOHC. 16 valves. Hydraulic tappets. * Fuelling: EEC-V controlled multi-point fuel injection * Power: @ 6300 rpm * Torque: @ 4200 rpm

Y5A/Y5B

* Capacity: * Bore x Stroke: * Compression: 10.0:1 * Valvegear: Chain driven DOHC. 16 valves. Hydraulic tappets. * Fuelling: EEC-V controlled multi-point fuel injection * Power: @ 5600 rpm * Torque: @ 4500 rpm.

Gallery

File:Ford-I4DOHC-cylhead-mounted.jpeg, Cylinder head without cam drive or valve lifters File:Ford-I4DOHC-camdrive.jpeg, Close-up of cam profile and valve lifter File:Ford-I4DOHC-camshafts.jpeg, The camshafts unmounted from the engine File:Ford-I4DOHC-engblock.jpeg, The engine block with the cylinder head removed File:Ford-I4DOHC-cylhead.jpeg, The cylinder head, seen from its bottom side

References

{{DEFAULTSORT:Ford I4 Dohc Engine I Gasoline engines by model Straight-four engines