Sound of  this Zetec in 3rd-4th gear  .9MB .wav

Ford Crossflow (Kent) to Zetec conversion

Main Page

What's a Seven?




Zetec vs. X-Flow

 Conversion to Zetec

Gearbox upgrade

 Maintenance Log






March 2002: build up a 200 BHP version of the 2 ltr Ford Focus Zetec to the replace the 150 BHP 1.7 ltr Ford Crossflow, aka Kent engine.

From March 2002 to December 2008,  about 50k miles have
been accumulated with the Zetec engine described here.
Mostly street, but also a dozen or so track events.

Some key requirements:
1. fit in the same place as the Crossflow. The current US-spec  Zetec Caterhams have the engine back by 2 inches. I also wanted to retain the existing gear shift location, the exhaust exit from the body, drive shaft and tunnel cover. The Zetec will thus be placed in the old Cross-flow location. This will just barely clear the timing belt within the nose cone.

2. switch from carbs to EFI requires a more complete fueling system, with an intermediate swirl pot, to avoid fuel starvation during lateral acceleration and to adopt the carburetor float bowl buffer function.  Fueling is arranged per Raceline's recommendation with a low (4psi) pressure piezo pump feeding the swirl pot & filter, which in turn feeds a 43psi high pressure pump. These items are mounted behind the rear bulkhead, on either side of the differential. The pressure regulator is mounted close to the injectors, to minimize pressure oscillations.

3. Using Raceline's pulley arrangement cleans up the original complicated situation.
Also using an under drive pulley for the 45 amp Valeo alternator.

Key components:

 Raceline's 200 BHP EFI 
XF-Zetec conversion kit

Exhaust headers and engine mounts from 
James Whiting
(thanks to Graeme Gee, for trying this first!)

intially GEMS later DTA S60 ECU
Lumenition 45 mm TB's
Raceline Alu bell housing retains XF starter, low on the sump exhaust side.

Fitted first with the sump, to ensure proper alignment later on when liquid gasket is
used between block and sump.
The thin spacer plate is discarded.

Ground clearance is about 2.75" with 15" wheels and me in the car.

On the track with 13" wheels, it's 1.75".

2001 Focus engine obtained from a crashed US-spec Focus ZX3 dealer vehicle. The dealer mats were still in the car. 120 miles on the odometer. Steering pump fluid all over the engine, but otherwise like new.

As it comes out of the Focus it's a cluttered assembly, yet under it all is a pretty compact engine.
Note: that EU and US spec Zetec's differ in many areas.

Cams will be replaced with Raceline 200 spec Kent cams.
These have 270dg duration, fuller [Time x Duration] curve and 9.75mm lift 

30mm Tappets
31mm Intake valves
28mm Exhaust valves

Std. head thickness is about 180mils. Taking off 40mil, will raise CR from the std. 9.6:1  to  10.5:1

Look low-center in the left image, through the coolant passage to see the 'before' 180mil head thickness. It's not generous. For further CR increases modified pistons are recommended.

Right image - before porting... lots of room for cleanup.

Raceline Kent cams (left) and ZX3 Focus cams. Main difference is faster rise and and close ramps, significantly increasing time-duration.

Kent vernier cam wheels facilitate timing.

exhaust valve flowIntake valve flow inspecting flow around the valves with valves at full lift with new cams and at .050".
The combination of a vacuum cleaner and a flow meter will work reasonably well.
At low openings, the edge of the squish area actually disrupts flow and should be "smoothed", same around the plug area.
Plated engine mounts make great handles while working with the engine.

Left side needs a spacer and some re-alignment

Cc-ing the chambers to ensure equal chamber volumes.  Use thin oil to reduce spillage.
Spark plug elevations are used for adjustment.
See valve flow inspection pics above (2 rows back).
Raceline Flywheel 5.8kg. Starter ring located for match with Crossflow bell housing and starter patterns. New clutch as well. I retained the original cable operated arrangement.
Note automatic (L) vs manual crank trigger housing. Glad someone pointed that out to me... thanks Doug!
Successful trial fit of water rail and exhaust headers. The water rail needs machining at the front to fit US 2.0ltr Focus head. Headers are very close to equal length, unlike the original headers that were shipped with the Crossflow.

Polished stainless collector artwork as received.

Baffle cover
Windage tray
The Raceline Sump has a baffle cover and a windage tray in addition to the compartments in the base. The windage tray reduces oil pickup on the crank counter weights, while the boxing of the oil reduces oil starvation during lateral acceleration.
Differences in detail exist between EU and US spec engines, so be prepared for the occasional fitting and grinding.
Lumenition 45mm Throttle Bodies Lumenition 45mm throttle bodies and throttle linkage

Far Left - ARP rod bolts installed.
Mid-left - Note conrod bearing fit using the "broken one piece rod" technique.
Mid-Right - ARP bolts for 2.0 ltr Zetec.
Far-right - left ARP's, right standard

Left - conventional method for finding TDC with dial indicator. There is an opening on the left of the block for a special Ford tool, which isn't needed.

Right - fully assembled. The alternator does not fit. Had to order a new alternator. The 45amp right side mounted Valeo works with the brackets provided by Raceline.
Note: a separate ground lead is needed, as the brackets are insulated! (i.e. from the alternator body to the block)

Installation in progress (4/14/02)
Left: Wiring.   Mid & Right: Headers fit perfect, and are very near equal length.

On the Focus (ZX series) engine, the dip stick (on top) does not fit like the Contour/Mondeo engines and needs some bending of the bracket to land just behind the new thermostat housing.
I.e. provided the Raceline water rail is being used, which moves the T.stat to the forward location.
Fuel return from the swirl pot goes in next to the fuel gauge potentiometer. Not much room to work with, but it all just works out. Note slight relief of the disc, just under the fitting, which is needed to provide clearance for the hose.

The original vented filler cap is retained. The added length of copper tubing for the return, reduces vapour buildup in the tank, by reaching near the bottom of the tank.

From left:   Swirl pot and high pressure pump on Alu mounting plate. The 45 dg orientation is to ensure that hoses do not project below the boot floor or chassis floor. 

This assembly is mounted to the right of the diff, the low pressure piezo pump is mounted to the left of the diff, on a bulkhead diagonal.

The low pressure Piezo Facet pump is mounted on rubber isolators. This also implies the need for  Also note small in-line filter.

Engine installed in the original Crossflow location. To maximize (optimize) the ground clearance, about a 1/4" needs to be removed from the vertical valve cover edge, to clear the nosecone.

Even with the engine forward, the feared excessive understeer has not manifested itself.
The Alu bell housing saved 20lbs, hence the total weight increase is limited to about 40lbs compared to the XF installation.  From 1280lbs to 1320lbs with a full 10gallon (US) tank. (37.5ltrs)

Left - Installation complete
(note the yellow banded alternator ground lead on the top alternator mounting lug -
the three mounting locations have isolating rubber bushings in them, hence the need for this)

Right - getting close
Comparing 5" and 7" mufflers on the old Crossflow:

Original 5" stainless muffler and heat shield and new 7", both on the XF1700. Just wanted to compare the difference.

Initial trial run of JW's 7" stainless polished muffler dramatically improved low and mid end  Crossflow's running behaviour. Sounds great too. 

In 2000 I wrote: "Wait and hear what it sounds like on the Zetec". Well... clearly a lot more power, but not quite the magical racy Crossflow sound. The Zetec comes on nice >4000rpm, and then it starts to sound good. Over 5000rpm it sounds great. Some audio from a lap at Black Hawk Raceway. (900kB)

The Zetec low end power is quite tremendous, but there are two "power jumps" one at 4000rpm and another around 6000rpm.

Pics: Top left = constructing the wiring harness, using the supplied connectors and  #16 wire (ignition / injection / power) and shielded cable for sensors.
Top right = Assembled with heat shrink and ty-rap color coding
Bottom left = 4.7Ohm/25Watt, injector series resistors. The injectors are low resistance Magneti Marelli items.  The resistance limits the holding current, but also shortens the turn on time (proportional to "Inductance/Resistance")
Bottom right = first pass tuning session. Eventually the ECU is mounted left of the steering column under the scuttle .. it just fits.

The original GEMS unit failed (glitches and lost RS232 port function). 
I replaced this recently (11/06) with a DTA S60 controller. This is quite a step up from the old GEMS, both in control functions, features and user interface and data logging capability. Tuning with this unit is a breeze, as the aux. inputs wired directly to my Wide Band O2 unit (UEGO).

The PC user interface is excellent with a wide range of manual and automatic loop control functions. Cold start, sequential injection, rev limiter, etc.

It also supports the standard Ford wasted spark (2 x 2) while the injectors can run full sequential. For startup it runs in batch and then switches over at a programmable rpm setpoint (e.g. 1200rpm), to ensure the engine runs smooth, even with a light flywheel (which may otherwise cause cam-errors). The cam sensor is needed for sequential to determine 1 of 4. With batch mode, all you'd have identified is TDC and BDC, not which cycle.

Support for DTA is very good, with a web focus group and free updates.