Fitting a Turbocharged Zetec engine

There are a few modifications which need to be made to get the engine to fit. Getting it to run is a different story.

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Lowering the compression to prevent Detonation.

This can be done by 2 methods. Increase the height of the head by fitting a spacer plate, or fit low compression pistons.

Fitting a spacer plate saves having to dismantle the block, but can provide other problems such as  clearance for the front exhaust pipe running under the  sump, finding a longer cam belt which isn't to short or to long, finding longer head bolts which are just as strong as the original ones, and clearing the underside of the bonnet as the top half of the engine is raised.

I opted for low compression pistons with shot peened conrods
so I can run reasonably high amounts of boost without worrying
about detonation or lack of strength in the bottom end.

Fitting the CVH exhaust manifold to the Zetec head.

This is surprisingly an easy job since the bottom row of studs on
the Zetec head line up with the bottom row of holes on the CVH
manifold. This means that you will only have to drill and tap threads
into the top row. Fortunately the top row of holes are all on a flat
surface along the Zetec head, but the top n/s hole goes into an
oilway inside the Zetec head. There are only 2 ways around this
problem, either miss out this hole completely (i.e. don't drill it out),
or re-fit the stud with locking compound such as chemical metal
to re-seal the hole.

Also the old Zetec breather hole on the front needs blocking. A simple plate with 3 bolts and a gasket does the job nicely.

Feeding oil to & from the Turbo on a Zetec.

The Zetec engine has an oil pressure switch screwed into the rear of the block which is perfect for replacing with the oil take off adapter from the CVH engine, which will allow you connect the top oil feed pipe to the Turbo.

You will also need to fit an oil return pipe from the Turbo to the sump.
This can be done a number of ways. I have an aluminum
pipe welded into my sump, as the sump itself is also aluminum.
If you wanted, you could just screw a threaded pipe into the sump
and seal it with locking compound.

When it comes to fitting an oil filter, you must fit a standard Escort/Fiesta filter as the longer Mondeo one will foul the o/s chassis rail. Fortunately the filter thread sizes are the same, but there is still not inough space to fit the water cooled oil cooler so this will have to be discarded.

Modifying the top engine mount from a CVH engine.

The engine mount to be used will obviously depend on the car which the engine is to be fitted into, but for this explanation I will show my own Mk4 Escort CVH engine mount.
Due to the shape of the Zetec casting, 2 parts of the mount need cutting off. Inside the squares are the sections which I shaved with an angle grinder.

When it's time to bolt the engine mount to the engine you will notice that only 2 out of the 3 bolt holes line up on the Zetec block. This is perfectly ok and will still be strong enough to hold the engine to the car.

Before.

 After.

Fitting the CVH gearbox to the Zetec engine

This, when combined with the modified engine mount, allows the complete Zetec engine to be mounted in place of the CVH.

To do this you must fit the old CVH flywheel. WARNING, Under no circumstances must the flywheel of an MFi engine be used. The flywheel from a CVH EFi MUST be used as they have magnets built into them to allow the Zetec's Crank Position Sensor to operate correctly. I have used the one from my EFi XR3i (same as Orion EFi Ghia & some MK5 Escorts) which is a 220mm flywheel. You can use the flywheel from a Fiesta XR2i or Turbo, but they are only 200mm, therefore the Escort flywheel can provide more clutch grip.

Fitting the CVH flywheel to the Zetec crank is not a straight forward job as you have to drill all of the main bolt holes by an extra 0.5mm each. Once this has been done, lining up the flywheel is not a problem, as one of the holes is offset so it can only be fitted in one position. When the flywheel has been successfully bolted onto the crank it's now time to sort out a suitable clutch. As I intend to run up to 280Bhp there was only one choice to be made, an AP paddle clutch. And since I am using a 220mm Escort flywheel, I have fitted a CVH Escort RS Turbo sized clutch, but if you use a Fiesta 200mm flywheel, you can use a CVH Fiesta RS Turbo sized clutch.

Finally when bolting the CVH gearbox to the Zetec block, all but one of the holes line up. This in itself does not present a problem as long as you fit the CVH dust covers to prevent stones from flicking up into the gearbox and reaching warpspeed by bouncing off the flywheel at full revs.

Fitting a suitable alternator to the Zetec engine.

As the Zetec power steering pulley and air con pulley are not used a suitable alternator and drive belt have to be used.

Luckily the Zetec has the same bolt holes for the CVH alternator mounting bracket as the CVH itself. I have fitted my standard Escort underhung alternator bracket complete with the CVH alternator. The next problem is that the CVH uses a single 'V' shaped alternator belt & pulley, but the Zetec pulleys use a multi 'v' pattern, so I fitted a multi 'v' pulley to the CVH alternator, this was sourced from a dead 1.8 CVH Sierra alternator. The belt which was fitted was an FAI 4PK0950 from Halfords, which is basically a 950mm multi 'v' alternator belt.

Fitting a suitable inlet manifold to the Zetec head.

One of the things that electronic injection is good at is running a 16 valve engine, so I decided to keep my already modified Fiesta RS Turbo injection system and modify the engine around this rather than the other way round. This meant either fabricating a custom inlet manifold or modifying the CVH manifold to fit the Zetec head. I decided to keep my existing EFi manifold to get me back on the road quicker and achieved this by fitting 2 spacer plates onto the EFi manifold. One to re-align the mounting holes for the face of the head, and the other to allow the intake on the throttle body to clear the top of the rocker cover.

These were created by Ian Howell, formally of Fiesta Frenzy & co.