Zetec/CVH hybrid engine for the Quantum


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It has come to my attention that there are people on Ebay is selling cd's and files with copyright information from this site (and several others on the net) without my permission.

This does discourage me somewhat from publishing any more details on my conversions.

 I specifically now have details and pictures of doing the 2.0 ZVH conversion by welding the head and using a Focus RS head gasket to solve the problem of using Felpro head gaskets.


While I'm fitting the engine into my Quantum 2+2  (Details here) most of the info will apply to fitting the converted engine into a Mk1/2 Fiesta or Mk3/4 Escort.
For more details on fitting a complete Zetec into a Mk1 Fiesta visit www.Zetecinside.com
The reason for fitting the Zetec block to a CVH head is that you can retain all the inlet and exhaust manifolds, fuel injection system etc on the CVH head but gain the strength and extra capacity of the Zetec bottom end.
I bought a Mondeo 2.0 Litre engine with 29K miles on the clock for 500+vat, it came from G.W & G Bridges Ltd, with 12 weeks warranty but I suspect what I did to do to it will have invalidated the warranty.

Here's another owners homebuilt Turbo ZVH engine, a 1.8

One step up from the ZVH is a full Zetec Turbo, here's a excellent site on how to build one yourself

ZVH FAQ (Frequently Asked Questions), please read before you email.

Fame at last, this site has had a mention in the November 2001   edition of Which Kit. Now also mentioned in Fast Ford May 2004

Page 17 Closeup

 Fast Ford letters page


This project is now more than theory, I'm driving the car   

MOT passed on 24th July 2001, The engine has now run for 8000 miles including a almost non stop John O Groats to Lands End run in 20 hours.

Now been rolling road tested at Owen Developments, running with 10Psi boost the power output was 226bhp at the wheels, estimated 259 bhp at the engine, 260 ft/lb of torque at 5520rpm.


 Engine installed in car.Engine installed in car.During instalation.


Details of what needs doing to the Zetec bottom end.



The oil return galleys don't line up with the head. 4 of the oil galleys need plugging as they are under coolant holes in the head.
The 4 holes that need plugging are on the bottom in the pictures.
They are highlighted in green in the LH picture.
Luckily the head bolts and oil feed do line up.
The holes have been blanked off with press fitted brass plugs.
The holes aren't drilled at 90 to the block surface unfortunately so the block needs skimming off to make them flush.
When this was done it turned out the block surface varied by about 3 Thou, low around the bores and waterways and high round the edges.

Oil feed to head.

I only found this potential problem area fairly recent when i had the cylinder head off to change the head gasket (which had blown due to the engine running weak).Head gasket upside down looking at surface that mates to headCloseup of problem area around oil passage.

There is a water passage in the Zetec cylinder block which is very close to the oil way hole in the CVH head gasket, look at the pictures and you can just see the impression of where the gasket has squashed into the hole in the block, it's only about 1.5mm from the edge of the of the oil passage opening in the gasket, nasty.

My fix was to fit a 'O' ring into the hole in the gasket to stop oil pressureGasket fitted with 'O' ring. reaching as far as the thin section of gasket. The 'O' ring wants to be slightly thicker than the gasket and of a suitable size for the hole in the gasket, mine stayed put in the hole quite happily without popping out. I don't know if this will be a problem on all engines, it may just be the combination of the gasket I've got and where passages are in my block but check them to be sure.

Cylinder head.


The cylinder head doesn't actually need modifying to use it on the ZVH but it makes sense to improve the head to help it match the increased capacity of the larger bottom end.

My head has been modified to pretty much the maximum possible by Dave at Pumaracing but it cost 700 inc.

I think it was worth it, he's done a great job.

First time I've had modified spring seats and valve caps to take the dual springs properly which is more than can be said for Piper kits.

Head after painting.Inlet portsExhaust ports

Inlet port.Looking into inletExhaust portLooking into exhaust

Valves, dual springs, spring seats, caps.



If it's a Turbo CVH that's being converted the Zetec pistons may need replacing depending on the amount of boost you want to run, Burton sell some Accralite pistons specifically for the ZVH conversion.

However, Paul Rye is apparently running a ZVH Turbo  with the original Zetec pistons and 1 Bar boost.
The compression ratio with the standard 2.0l Zetec pistons and a standard 55cc CVH turbo or 1600i head works out at 8.6 to 1 which is really too high for a turbo.
Initially I'd hoped to reduce this by getting Dave to enlarge the combustion chambers in the head but it's turned out to be too much to gain that way (he got 57cc) so I've skimmed 0.5mm off of the top of the pistons, this drops the compression ratio down to 8.2:1 which is about what I want.
Apparently the Zetec pistons skimmed 0.5mm like this are ok up to about 1 bar boost.
Skimming standard Zetec piston

These are details of some Accralite 2.0 pistons from Burtons web site, the 1.8 would needs 81mm diameter pistons but these aren't mentioned. These ones cost 450 a set and they come with unmachined 12mm crowns.

Car/Engine type: Cyls Capacity Bore size


Crown Part No
Ford CVH/2.0 Zetec conversion 4 1997 85 35 Flat FZ142

There has also been mention of using Calibra pistons with a 1.8 block bored out to 83.5mm (from 81) giving 1.9 L and also of  using Celica GT4 pistons in a 2.0 block bored out to 85.5mm (from 85) giving 2.1 L


Piston Rings.


While I had the pistons apart for skimming I checked the ring gaps as Dave was worried that they might be a big tight as standard for a Turbo engine.
Probably a good thing he did as the top ring gaps were 10 to 12 thou, lower than the minimum gap specified in the Haynes manual and almost certainly to small for use with a turbo.
I machined a groove in a piece of alloy the same size as the bore and used that to hold the ring and act as a guide for a 20 thou thick cutting disc in a mini drill.
This gave me a nice ring gap of 25 thou
The 2nd and oil ring gaps were fine as they were.
Not my hands
Water Pump   

Use a CVH water pump, the Zetec Mondeo one spins the wrong way and the Zetec Fiesta/Escort one is no good as the water pump is driven from the alternator belt which means the pulley on the water pump fouls the side of the engine bay.
I initially didn't want to just drill the block for the CVH waterpump as where the new holes need drilling the block appeared only a few mm thick so I made up an adaptor plate from 2.5mm thick stainless steel with 3x 6mm studs Loctited in to take the CVH water pump.
This method didn't work, the plate distorts too much when the pump is bolted on.
After a well timed email from Clint Gaskin (thanks) and a bit more research I've concluded that I was trying to be too clever and I should just drill and tap the block for the 3 new CVH mounting holes required.
I can still use the adaptor plate I made but without the studs, just holes straight through.
By mounting the pump at an angle I was able to use one of the existing Zetec pump mounting holes, this hole has a M8 to M6 stepped stud fitted. The top left hole one breaks through into the end of the head bolt hole at about 10mm deep, luckily below the end of the bolt.
The bottom left one is only in about 3mm of metal and is the one most likely to give problems.
The bottom right hole I drilled about 10mm deep without breaking though.
A hole the same size as the tapping drill (5mm) in thick lump of steel was used to keep the drill straight, the hole in the steel was then opened out to 6mm and was used to keep the tap straight as well.
I wanted to avoid modifying the CVH water pump if at all possible to make it easy to replace with a standard pump if it fails, I ended up having to remove a small amount of metal to clear the head of one of the plate mounting bolts but it was only a few mins work with a carbide burr in the electric drill.

Zetec 2.0 top, CVH XR2 1.6 bottom.CVH waterpump with modification. (Black area).Block with stepped stud fitted.Adaptor plate fitted.Water pump fitted.Kit of parts.Drilling the new water pump mounting holes.Lots of holes.
Timing belt tensioner

A CVH cambelt tensioner is used, one from the 1300 CVH, as it's smaller than the 1600 CVH one.
But depending on exactly where the water pump is fitted there may be enough room for the 1600 CVH tensioner..
Needs bolt holes drilling in block using the same method as the water pump, using the thick block of steel to keep the drill and then the tap straight.

CVH 1600 top , CVH 1300  bottom.First complete assy of timing belt, tensioner and pump.

Pulleys and spacers.


Use the CVH crankshaft timing belt pulley, the Zetec one has more teeth.
Leave off the spacer that was behind the Zetec pulley as the CVH one has it as part of the pulley.
There's not enough room between the engine and chassis member to use the Zetec flat belt pulley so use the CVH one.
A 2.5 or 3mm spacer is needed behind the camshaft pulley to equalise the distances of the pulleys from the block so the cambelt runs fairly close to the centre of all the pulleys.
The crankshaft pulley determines the position of the belt on the other pulleys.
I've done an Excel spreadsheet which has all the figures on it, there's a web page with an interactive web version of the table here.
Zetec top , CVH bottom.2.5 to 3mm spacer to fit behind cam pulley.

Top left engine mounting.


Again, it seems the CVH one nearly fits straight on, nearly....
The top 2 bolts line up and put the mounting at the right height but the 3rd hole on the bottom right is about 10mm higher on the Zetec block .
This is under the horizontal section of the bracket so it's not just a case of drilling a new hole.
I hacked off the section of the bracket that's over the hole that can't be used and will weld some extra plate on to the bracket to pick up on the bottom left hole in the picture.
Initially I made and welded on the extra lug to pick up on the bottom left.
Welded quite nicely, I welded an edge around the lug, just like the original.
After I'd done that I looked at the last hole, the bottom right one and decided to use that one as well.
I cut a slot through the horizontal section of the bracket and welded in a tube to take the 4th bolt.

CVH top engine mount, 2 of the 3 bolts line up.A few bits removed.A few more bits stuck back on.All 4 bolt holes used
Oil Filter.


The Zetec oil filter comes straight out the rear of the oil pump, a completely different place to the CVH one but at least it won't pour oil all over the driveshaft when you change the filter.
If you are doing this conversion on a Fiesta (maybe Escort as well) I believe you need to replace the Mondeo oil pump with the Fiesta/Escort Zetec one which angles the oil filter in and clears the chassis rail on the side of the engine bay
There's enough room on the Quantum for me to use the Mondeo one.
However the CVH engine has an oil to water heat exchanger fitted between the oil filter and block and that doesn't fit so I'll replace it with a external oil cooler, using a remote oil filter as well.

 steering arm clears filter but no space for a cooler as well.

I'd been told the  sump may have to have a little machining done to give the downpipe a little more clearance but it doesn't need any modding on the Quantum so I'd have thought most Escorts and Fiestas should be ok as well.

 Sump clearance fine, driveshaft might cook though.
Crankcase breather outlet/Turbo oil return inlet.  

The Mondeo has it's crankcase breather outlet on the centre front of the block.
Unfortunately this is direct under the turbo manifold, so I've made a blanking plate up to cover it, including some nice semi CSK allan bolts.
This also means I need 2 new passages into the block, 1 for the Turbo oil drain and 1 to replace blocked crankcase breather.
I was going to drill through the rear of the block to fit a breather outlet where the CVH one was but luckily I didn't as I now want to use a gearbox from an Mk5 Zetec Escort which has the starter at the top rear of the engine. Right where I would have drilled the hole.

For the oil return I drilled out an existing 10mm blanked off hole in the block out to 18mm, initially drilling it out to 11mm and then using a counterbore bit guided by the 11mm hole to drill it out to 18mm.
I machined up a new pipe fitting about 18.1 mm dia and then used a bolt and spacers to pull it into the hole. 

Drilled and tapped another "spare" mounting on the block 3/8" BSP to take a right angled pipe fitting for the breather.

Original crankcase breather outlet in centre of block.Blanked original breather outlet and location on new oil return.New oil return for turbo.Remove around 25mm from turbo oil return.Parts to drill hole for and fit new oil return.New breather outlet.

Alternator mounting.


Use the CVH alternator mounting bracket, it bolts straight on.
The dipstick does clear it which is good.
This is the overhung alternator bracket, used on most Mk3/4 Escorts, there's also an underhung bracket which is used on most Mk2 Fiestas, this is the one I've used.

Overhung alternator bracketUnder hung bracket and alternator.
Cylinder Head Bolts

The Zetec block has the start of the head bolt threads 14mm below the top of the block as opposed to the CVH head's 3.5mm
As a result the CVH head bolts are now too short.   
The normal head bolt thread engagement on a CVH is ~17mm, using the same bolts on the Zetec block would only give 6mm engagement or 9mm you replaced the 5mm thick CVH washers with 2mm ones.
9mm isn't enough engagement to be sure of not stripping the block threads when tightening the head bolts. Nasty !
I need 145 to 150mm bolts to give me at least 17mm of thread engagement.
The Zetec bolts don't even make it through the head.
I bought some 150mm long HT cap screws, gives me about 25 mm thread engagement in the Zetec block.
Dave has recommended tightening them to 75 lb/ft.

Cylinder Head gasket

The 1600cvh Bore is a fraction under 80mm, the 1.8 Zetec is 80mm so you can use the 1600CVH head gasket with no problems on the 1.8 ZVH.
Unfortunately the 2.0 Zetec bore is 84 mm so you can't use the CVH head gasket as the edges of the gasket will be exposed and will burn away.
You can use the 2.0 Zetec head gasket but it's oil passage goes of of the edge of the CVH head so it needs the edge of the head built up with weld and the head skimming flat again.
I've found a suitable gasket, thanks to Dave at Pumaracing, a Felpro competition gasket, used on American 2.0 Litre CVH engines.
Felpro part No. 9303PT2 but I believe part No. 9309PT is the same.
86.7mm bore and 1.83mm thick, perfect.

2.0 Zetec top, 1.6 CVH bottom.Felpro gasket, top bottom and bottom top, oops.

The 1.6 and 1.8 Fiesta/Escort Zetec flywheel takes the same 220mm dia clutches as the 1600 MK4 Escort so any heavy duty clutches for the Escort RST will be fine.
I ordered a Heavy duty AP clutch centre and cover from from
R.S Cosworth specialists, a very helpful company and very good prices as well.
N.B I had big problem with this clutch not releasing, more info here on the main Quantum page.

AP heavy duty clutchAP heavy duty clutch fitted.



The bits that you need to get hold of from a 1.6/1.8 Fiesta or Escort Zetec if you use a 2.0 Mondeo Zetec block and why:

The 2.0 L Zetec is only fitted to the Mondeo, this is a bummer as quite a few bits are different between that and the 1.6/1.8 Zetecs from a Fiesta or Escort which are easier to fit but of course 200cc smaller and we can't have that..



The deep section is in the wrong place on the Mondeo

Gearbox Shim/Spacer.

The thin Spacer plate from between engine & gearbox (different shape). 

2.0 Mondeo Zetec left, 1.8 Fiesta/Escort Zetec right
Oil pick up pipe and strainer.

Different shape needed to fit the new sump. 

Mondeo top, Fiesta bottom.

Dipstick & dipstick tube. 


The 2.0 Mondeo one tries to go through the middle of the Exhaust manifold.
The 1.8 Zetec one nearly fits, will need a new bracket for the top.

I've actually cut the bracket off of the 1.8 dipstick and made a rather excessive complete new one from aluminum but most ZVH's seem to just have a bit of metal strip between the bracket on the dipstick and the top left exhaust stud.

Slightly excessive dipstick bracket.



The 2.0 Mondeo one is too big to fit in the CVH gearbox bell housing.
I didn't realise this initially and chucked the one from the 1.8 Zetec I got the sump etc from in the skip down the breakers ARGH !

Got another Fiesta 1.8 Zetec flywheel from Bridges for 25+vat.
The CVH one will fit (with the bolt holes opened out to 11mm) and work but doesn't have the holes on the back (unless you get one from an EFI CVH) for the ECU sensor which I want to use.
I recently been informed that the later Zetec flywheels are thicker than the CVH ones, this possibly only applies to engines with MTX75 gearbox's. 

2.0 Mondeo Zetec left, 1.8 Fiesta/Escort Zetec right2.0 Mondeo Zetec left, 1.8 Fiesta/Escort Zetec right


The 2.0 Zetec Mondeo engine and it's disassembly.


This is the engine exactly as it came. 

Click on these thumbnails for 1200x1200 pixel images (~320K)

Front view Flywheel view Rear view Pulley view

Click on these thumbnails for 896x600 pixel images (~135k) Some 1792x1600 images here

Some more pictures of the external disassembly of the Mondeo Zetec

Just so I can remember where the leads go.

Oil return/breather needs modding

The "spare" bits from the Mondeo Engine. It's Headless

Removed the head from the engine.  Front of block. Flywheel end Rear of block Waterpump/timing belt end.
Inside the Zetec bottom end.

After 29,000 miles no measurable wear.

Main bearings after 29,000 miles.Oil jets for cooling the bottom of the pistons.



ZVH FAQ (Frequently asked questions)

If you've read everything above and still have questions please read below, these are the most common questions i get asked about the ZVH.

Question: Where can i get the head bolts from and/or what spec are they ?
Answer: I got the bolts from my local fastenings company who surprisingly had them in stock. What you need to ask for are 150mm long high tensile steel cap (allen) headed bolts to 12.9 spec. 8.8 spec isn't strong enough. It will have 12.9 stamped on the head of the bolt and they are normally plated black.    I torqued them up to 75lb/ft in a couple of stages.

Alternatively you can get them from Burton Power, part number CV191HDL, they say torque them to 65 lb/ft

Question: Where can i get the oil gallery blanking plugs from ?
Answer: You can't buy them anywhere (that i know of), the holes that need to be blanked off aren't accurately machined so each hole has to be measured and the plugs machined to be a press fit into the hole. You should be able to find a local machine shop that can make them for you.
Question: Where can i get the head gasket from ?
Answer:  Up to 1.8 engines can use the 1.6 CVH head gaskets. After that you need a head gasket from the American 1.9/2.0 l CVH engines. The only one i know of available in the UK are the Felpro ones, part  No. 9303PT2 or 9309PT (don't know the difference) , they are sold by Burton Power or Specialised Engines
Question: Can't i just use the Zetec head gasket ?
Answer:  No, not without modifying the head. The oil feed to the Zetec head goes closer to the edge of head than on the CVH and if you put a Zetec head gasket on a CVH head the oil just leaks out the gap. You can get the side of the CVH head built up with weld and then the head skimmed to enable you to use Zetec head gaskets.
Question: Where can i get the water pump plate from ?
Answer:  You make it from some steel plate, or there always seem to be some on Ebay at the moment. I suspect Burton Power also sell them.
Question: Can i fit the turbo oil drain and/or the breather outlet into the top of the sump instead of the block as it's a lot easier ?
Answer: You can and a lot of people have but there is the potential for oil surge to cover the outlets and stop the oil draining from the turbo or the crankcase fumes escaping from the bottom end properly so i'd not recommended it personally. I think if Ford could have got away with fitting the outlets in the sump they would have on the Fiesta and Escort turbos rather than making the block non standard.  If you must put the outlets in the sump then make sure they are right at the top.
Question: Can you build me a ZVH engine ?
Answer:  I'm afraid not, I've a full time job as an electronics design engineer and I'm currently not getting enough spare time to get on with my own projects let alone do other peoples.  Your best bet is to ask on the RS owners or XR owners club forums for recommendations of a company to supply an engine, i know Burton Power do them.
Question: Can the 16v Zetec head be fitted onto a CVH block, a reverse ZVH ?
Answer:  Yes, it has been done but it needs the head and block modifying to add extra external oil drains from exhaust camshaft.  But i can't really see the point as the Zetec will fit in any engine bay the CVH will so why not use the complete zetec, see my other page here
Question: Is the original KE Jetronic fuel injection system from the Escort RST suitable for a ZVH.
Answer:  Only just in my opinion if the ZVH is running low boost especially if it's a 2.0 ZVH, it may do to get you running with the new engine but make sure you get it all setup on a rolling road before you melt the pistons. If you want more than about 180bhp then replace the injection system with an aftermarket system which can be setup properly.
Question: Are Burton Power paying you to link to  Burton Power a lot ?
Answer:  No, just a satisfied customer and I know they do the parts. However if they want to give me some freebies i won't say no.











Many thanks to:

Any questions, answers or errors spotted please Email: Jim Hearne but please only email if you are sure it's not covered above as i get far too many emails asking the same things.

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