What Is A Zetec Engine?
Zetec is the name used to designate a series of four-cylinder, multi-valve DOHC engines produced beginning in 1991 (Ford initially called it the “Zeta” engine). The motor carried the CHV long-running engine block as its basis and was initially developed in 1.6L and 1.8L displacements, with the 2.0L introduced in 1993. Ford planned on using the new engine to replace the CHV they had been using during the eighties.
The Ford Zetec engines were produced in three primary variants. Zeta, Zetec-SE, and Zetec - R. The original Zetec (Zeta) engines were used until 1998 when Ford redesigned the motor in a joint effort with Yamaha and Mazda. This engine had the codename of “Sigma” - ranging from 1.2 - 2.0L versions and is a radically different engine than its predecessor. In 2000, the Zetec Rocam engine was developed as a cheaper design with chain-driven SOHC with eight valves and was used in international markets like Europe and South America.
The base 1.6: Zetec engine was capable of producing around 115 hp, and the 1.8L bumped the horsepower up to 130 hp with different camshafts, usually found in the Fiesta RS1800i (which Ford used for a couple of years in the mid-nineties. Most tuners prefer the 2.0L Zetec, capable of modest gains with relatively minor tuning.
While Ford redesigned the 2.0L Zetec engine in 1997 after introducing it in 1992, it remains a favorite among tuners. Early models have coined “STs” due to their silver cam tops. Later models were “BTs” designated by a black cover. The ST engines have a one-piece sump, while the BTs have a two-piece configuration.
What Are the Best Ways To Improve Performance?
One can do various things to improve the performance of a Zetec engine. While there are abundant aftermarket tuning kits built for the Zetec engines, only some are worth the money you are likely to spend on them. Some require extensive modifications to the engine, so be prepared to spend some money turning your Fiesta or Focus into a speed demon. We’ve included some tips below.
Get Your Engine Running Right First
If your Ford Zetec engine exhibits rougher behavior than usual, you must first address the elephant in the room (lousy running engine). It will do you no good to try and boost the performance of an engine that isn’t running smoothly in the first place. Get new oil, change the plugs, and do a tuneup if needed, but get the engine purring before ever attempting any upgrade modification.
Every tuner knows that the best way to increase the power and performance of any naturally aspirated engine is to increase the air and fuel mixture. Most people think adding a high-powered turbocharger is the best way to increase horsepower, but this is not true. While a turbocharger (or any kind of forced induction does get more air into the engine by compressing it (creating more oxygen), it often requires making other tuning adjustments (new fuel injectors, new cams, lower compression ratios, and remapping the ECU).
Replace To A Performance Camshaft
Replacing the stock camshaft with a performance can dramatically increase performance and power. Fast road camshafts often produce higher rpm, although you may notice less power in the lower range. Installing a Motorsport camshaft will not work for a daily driver since the cam will seriously affect the car’s idle (it will ride roughly). Competition cams are designed to produce the maximum rpm but are not anything you want if you plan to drive the car to the store rather than on the track.
Increase AirFlow With Manifolds And Valves
The design and flow of the intake and exhaust manifolds can significantly improve a Zetec engine. It is not uncommon for the headers to need replacing on these engines. Changing to a larger valve kit can help improve the airflow into the combustion chamber and is often required when attempting to increase the performance of the Zetec engine.
Remap the Engine’s ECU
Since your car’s ECU controls the air and fuel flow rate into the engine, you will need to hook up the computer and reprogram it. With the advent of electronic fuel injection, manufacturers programmed the electronic control units with standardized performance scenarios. The computer considers the information many sensors relay and instantaneously adjusts in response to those signals. Things like temperature, air flow rate, quality of the fuel, and emissions are all processed, and the car’s systems adjust to meet ever-changing demands.
Most cars were built with ECUs that have a great deal of tolerance due to the different driving habits of owners. (It would have been impossible to program each car to each driver, so they set them to a “middle of the road” approach). Since there is plenty of room for finer tuning, remapping the ECU for higher rates of fuel and air can lead to great results. Usually, reprogramming your car’s computers will help provide a 10 - 15% power boost immediately.
Most of the stock ECUs can be reprogrammed for small, modest gains in horsepower, but if you are interested in more significant boosts, be prepared to go with an aftermarket ECU. Many aftermarket ECUs are on the market, but we like several that Mountune USA offers.
Consider A New Fuel Pump And Injectors
Any forced injection system will drive more air into the engine, but you will need upgraded injectors and a better fuel pump that can deliver the gas needed to mix with the new flow. Performance injectors can squirt more fuel into the combustion chamber, and a high-flow fuel pump can ensure that there is always a maximum fuel flow for optimal fuel efficiency and power output.
A daily driver might not need the performance fuel pump, but you will need it if you plan to turn an NA engine into a turbo monster. (You should note that both performance injectors and fuel pumps often require an adjustable fuel pressure regulator and a remapping of the ECU. The components are costly). Ford Power Products sells an excellent set of universal fuel injectors offered through SummitRacing. We recommend a Bosch unit like the one Pegasus offers for a high-flow fuel pump.
Lower The Compression Ratio
If you plan to slap a turbo on your little Fiesta, you will risk blowing up your engine if you do not lower the compression ratio. The best way to lower the compression ratio is to shorten the engine's stroke (which means new pistons and a new crank). Many tuners believe that remapping the ECU can lower the compression, but this is not the case.
Install An Intercooler
When an engine like the Zetec gets turbocharged, the increased force of the flow heats the air. You need to install an intercooler to keep those temperatures down, which will help not to overwork the engine. There are two types of intercoolers, water and air-cooled, but on the Zetec engine, the air-cooled version is preferable.
Improve Your Vehicle’s Suspension And Brakes
One of the easiest ways to improve the performance of any naturally aspirated engine is to upgrade your suspension and braking systems. Not only do these systems make your car safer, but they can aid your car’s motor by not wasting energy. (Better tires will also help grip the road, translating into better fuel economy, more grip, and better acceleration and stopping power).