Although this article is mainly aimed at the MK2 XR2, the engine (CVH) is the same as that of the one used in the majority of earlier (mk3/4) Escorts and Orions so the advice and performance mods still apply.

So, you want some more power from your beloved XR? There are several things that can be done relatively cheaply to aid performance and the general welfare of your engine.

BUT before you try anything make sure that it is serviced properly and that there are no majors problems with the engine. There is very little point in seeking more power from an engine that is knackered to start with!

It may also be worth checking / replacing ignition components such as leads, plugs, rotor arm and distributor cap, the CVH works well with NGK and Bosch super 4 items plugs and Magnecor leads.

Depending on how much money you have and where you want to set your goal at, there are many different routes that can be undertaken. To try and explain all of these would take forever so only the most effective / common methods are featured in this section...

Air Filter:

One of the most common first performance purchases and one which is worthwhile doing is the purchase of a Free-flow air filter, Approx. cost is £60. This means taking away the starship enterprise air box kindly supplied by Ford and replacing it with a bolt on unit. The most common of these and also the company that tends to recieve favourable reviews / results is one manufactured by K&N.

By swapping your original air box for one of the aforementioned items you will allow more air to pass through into the carb. This may give a marginal increase in power but be aware that it will not be particularly noticeable. However, where it is particularly noticeable is in the sound it will make, there is a definate enhancement to the induction noise.

This is a fairly straight-forward job to do yourself, and can be undertaken with a reasonable toolkit and with a reasonable understanding of the engine...However, on some models the carb must be re-jetted to supply enough fuel to compensate for the increase in air flow and this is more difficult to do (The jet is normally supplied with the new air filter). If you intend to try this yourself make sure you have a good guide or a Haynes manual to hand, otherwise get a qualified mechanic to help you.

There is unfortunately one major drawback of fitting this type of filter, and that is that over the winter months cold starting the engine becomes a problem. The engine will run more lumpy and depending on how cold it gets the carb can freeze after fast runs causing temporary stalling. It is therefore your decision to either put up with it or re-fit your old air box for the winter period!

Exhaust System:

The next step after increasing the flow of air IN is to aid the flow of gases OUT with a performance exhaust system (£50-400). There are different options to look at when upgrading the exhaust system, the rear box, system and system and manifold. The best of the bunch for the XR2 is probably Janspeed, Scorpion and Magnex, although if you want noise and performance more than anything else then ashley or having a custom made race exhaust are also further options to consider.

Normally replacing just the rear box will give no gain in power, which although in itself is nothing worth writing home about it can change the exhaust note of the car which is more important to some anyhow.

On the XR2 as the rear box is one third of the way down the system when purchasing a rear box or back box you will find it is simply a tailpipe trim with a foot long section of pipe which means the old exhaust must be cut through and the new section clamped on in its place. (On the XR2 doing this will not aid performance)

Replacing the whole system through should give an increase in performance and a nice raspy exhaust note. Unfortunately some systems will not fit the standard manifold due to the increase in pipe diameter and method of fixing to the manifold. Therefore on the XR2 the best solution is a full manifold and system. This will offer a power increase and sounds the best of the bunch! The manifold comes into its own at higher revs where a 4-2-1 or 4-1 will allow more gases out compared to an OE manifold, as well as usually providing a smoother less restrictive flow out.

Fitting a manifold and exhaust is not very difficult. However, before you start make sure you have the facility to safely jack the car up whilst working under it and also that you have the correct exhaust gasket. (It is also worth swapping the head bolts) Because of the sheer size of a stainless manifold compared to the original one the starter motor must be disconnected and removed to allow enough room to position the manifold. Once reconnected the results are quite pleasing with the exhaust note changing quite dramatically as compared with the standard exhaust system as well as an increase in power!

Performance Leads:

This is an area that is often overlooked when looking at the allround well being and performance of your engine.

The usual trick of certain manufacturers is to use a gimmick or demonstrate in one way or another that a bigger spark means more power. This simply is not the case and there are so many other variables, that you could study a degree on it.

You want a lead that can supply the amount required by the engine, no more as this is simply a waste and usually means other electrical components may suffer interference due to suppression levels.

You also want a lead that will withstand the elements for a long period of time and for those show off's out there one that looks nice too.

Although there are many different brands on the market your best off sticking with Ford OE parts as unless you are going for a large power increase they will be upto the job.

If you want something that looks better, lasts better and works better, then the tried and tested lead of racing drivers and fast road enthusiasts has got to be Magnecor, although a little pricey they will be one purchase you wont regret.

Performance Camshaft:

The next step is to fit a performance cam (£200 Approx.) Both Kent and Piper make performance cams for the XR2 and both are pretty much on par with each other in terms of performance, quality and cost. Although if you are looking into building a serious spec engine then Newman has got to be your cam choice with quality surpassing the rest of the competition by far.

In essence the cam will move the useable power band round the rev range. The CVH engine does not in standard form like revving much more than 5500rpm or at least there is no more power made (it just makes noise!) Depending on the cam you opt for the peak power and useable power is more likely to move to 6000rpm - 7000rpm although other engine components need to be looked at more closely if you intend to rev your engine to this and beyond on a regular basis.

However, this is all at the sacrifice of power low down the rev range.

Be wary of OTT claims by the manufacturers that fitting a particular cam will give you a 20BHP increase. In reality unless the head has been modified along with the cam that figure is very over ambitious. You will definately notice the increase in power and it will make more difference than the exhaust and air filter together in sheer performance terms.

Fitting a cam is not a very difficult job but should not really be undertaken unless you have good knowledge about how the engine works, if possible leave a garage to do the work and let them dial the cam in properly, as failure to run a new cam in correctly could result in a lobe or lifter eating itself rather prematurely and failure to set the cam timing properly could result in the optimum power not being obtained or worse if its really far out.

The only drawback of fitting an uprated cam is that tick over is lumpy, the wilder the cam the more lumpy it will be. However, the power gains more than make up for this and unless your going for a full race spec cam its hardly noticeable.

Head Work :

There are various things that can be done to the head to gain more power the most obviously is porting the inlet side of the head as it was restricted from the factory due to keeping costs to a minimum. There is no real need to port the outlet side as the ports are already plenty big enough and will see little difference other than to your wallet!

Gas flowing is another option which aids the flow of air through the head by polishing the air and fuels path through the head, this is itself is debateable point though as some people suggest that the inlet side should be left rough to enable the air and fuel to better mix together.

Bigger Valves and skimming are also both viable options to gain more performance...Bigger valves only really need to be done if you are going for a high performance engine with a wild cam, but should see an improvement at any stage of tune.

Skimming the head increases compression which in-turn gives a more powerful explosion and helps to make the engine more responsive.

Engine Re-Build:

If your engine is getting a bit tired or is starting to use up a lot of oil, or even if you just want the ultimate power...this is the option for you.

The block is usually rebored and oversized pistons (usually .5mm) are used (it is possible to use 1mm oversized pistons without any problem on an xr2 which in effect make it 1644cc) the majority of the other internal components are also replaced or re-worked.

This does not give an instant increase in power as the engine will have to run in before you can use it to its fullest. It does however give peace of mind that the engine is both wholesome and at least as powerful as when it rolled out of the factory many years ago.

Twin 40's / 45's / Throttle Bodies:

If you really dont care about lumpy tickover, loud engine noise and awful fuel economy (excluding throttle bodies that can be mapped economically)...this is the answer for you! Twin carb's / throttle bodies add a much needed kick to the cvh's top end which is particularly noticeable. The noise when being fully utilised is amazing and is the sort of sound you can never get tired of hearing.

Try and get hold of a re-conditioned set if you cant afford new, or alternatively get an old pair re-conditioned. It is probably not worth buying new unless you really are after the ultimate power gains (down to the last bhp).

Try and get a set as closely jetted to your engine size as possible and check to make sure you have all the chokes, trumpets, and jets. Many of the twin 40's and 45's available from Weber, Dellerto and Solex are very much of a muchness. However, parts for them are not, unless you have a very good supplier...stick with weber, as parts and expertise is readily available.

Throttle bodies are the most costly of them all as they require 4 injectors as well as engine management and mapping - costly in short. Although this gives the most flexible and accurate method of gaining driveability and power of the three.

Turbo Charging:

As a final thought for power, dont forget that doing all of the above will give you around a standard escort or fiesta turbo engine unless you are really sinking some money into it - so an engine transplant maybe the route for you to go for more power.

Bear in mind however that there is quite a lot of hassle involved (relocating the battery, adding a swirl pot etc.) rewiring the dash / loom to name but a few.

This does however offer the ultimate route for power hungry drivers and so should be seriously considered before you start to seriously modify your car in naturally aspirated form.

Limited Slip Differential (LSD):

One of the most choice modfications and one of the most noticeable modifications is the addition of a Limited Slip Differential from an Escort Turbo! Its not wonderfully cheap bearing in mind a new series 1 LSD from ford costs in the region of £1200 - Do not be put off by this as cheaper second hand items are around.

Basically the guarunteed understeer on the xr2 is either reduced or removed from fast cornering! If you drive your car hard you will immediately notice the difference and providing you are prepared to keep your foot planted to the floor you will be able to utilise your engines power and pull yourself out of the majority of tricky situations you may find yourself in!

What it basically does is prevent either front wheel spinning and instead constantly drives both front wheels so even if a wheel brakes traction it will continue to scramble for grip. This is most poiniant when driving in wet conditions and makes even more of a difference.

If you take a closer look at the bottom right hand corner of the gearbox you can see how to tell the difference between the two! Not massive to look at - BUT a massive difference when driving!

One other thing to bear in mind is that although the Series 2 ERST LSD works well the Series 1 works that little bit better as it was a harsher car to begin with - unfortunately costs reflect this and due to is rareness a Series 1 LSD could set you back 1/3 to 2/3rds more to buy.

If you want to go a stage further then there is the option of adding a Quaife ATB diff and having driven with both setups I can confirm that the ATB is a noticeable improvement over the series one LSD - really working well the harder you accelerate - which is precisely how it works being a torque biasing differential rather than a viscous differential like the ford items.

Expect to pay around £500 new for an ATB but if your investing a lot of money in your engine you would be stupid not to invest that bit more in making sure you put down as much of your hard earned power as possible.

Flywheel:

In conjunction with the LSD's and gearboxes lightening and balancing of the flywheel is very much worth doing.

A lightneed flywheel means there is less mass to both spin up and spin down when you accelerate and on overrun. This in turn helps an engine to rev better.

It is said however that lightening a flywheel can affect top speed and sustained speed runs as the inertia that was once there is now lessened.

In reality with two degrees of lightened flywheels that I have used only once did I ever notice this on an uphill half mile stretch - and it still pulled to 130mph in an XR2 so its not that bad a side effect.

Exhaust Heat Wrap:

Although seemingly quite expensive this cleverly designed bit of kit can actually seriously aid your engines health and power.

The wrap itself comes in a large roll which needs to be moistened before beginning.

To wrap a manifold is not actually that difficult although to get it spot on will take an hour or two.

After the wrap is securely in place and has thoroughly dried (24 hours) you spray it with a further heat and protection treatment which boosts withstandable temperatures as well as colours and preservers the wrap.

The wrap works by keeping the manifold insulated which benefits your engine in two main ways:

Firstly there is a massive drop in the amount of heat in your engine bay, and as has been proven a colder engine is a more efficient engine. To give you an idea after a hard drive you can place your hand around one of the manifod branches without a problem (Please do not try this yourselves!!!)

The second is that by making the manifold itself hotter you charge the gasses coming out of the engine even more making them flow quicker out of your exhaust, the benefit is neglible but is certainly going to be a positive thing.

Having used this wrap for a few weeks now I can confidently say that it has dropped the engine bay temperature by around half what it used to be (which with open twin carbs has got to be an advantage)..

For final thought next time your watching the WRC or similar and you see one of the engine bays check out what they are using on there exhausts and turbos...It wouldnt be on those sorts of cars to just look nice now would it!