Retro Ford, December 2007
XE into Escort guide: Defecting to the dark side
Vauxhall engines in old Fords is always a hot topic for debate, get involved with our handy guide.
Words: Ben, Pics: Various
Call it the modern answer to a BDA or call it treachery to the blue oval, you can't argue with the C20XE's reputation for cheap power. Of course, it's all relative, but until the recent rise of the Duratec, the XE has been kings of the multi-valve castle. The Cosworth YB is a great engine for big power, but can be costly to make it work properly when it does the breathing itself. The Zetec will produce the numbers too, but some folk argue that it's a tad on the pricey side. This is where the Griffon shoulders its way in. With a reputation for good power in standard trim and even better power after a few basic modifications, it's definitely worth some thought. The popularity of the XE stems from it, at one point, being the motorsport engine of choice for sub two-litre naturally aspirated classes.
In standard, Astra GTE trim the Vauxhall unit produces 150bhp and 144lbft. Bolt on a set of carbs and a four-branch manifold, you'll have around 180bhp; change the carbs for throttle bodies and you'll be knocking on the door of the magic 200bhp. Some clever bugger then realised that you could turn the engine around to power the rear wheels and this opened the floodgates to rally Escorts everywhere.
Don't fear this conversion, embrace it. Thanks to the likes of SBD you can buy everything that you need to defect to the dark side with relative ease. Bellhousings, engine mounts, sumps and now armed with this handy guide, you can get one in your Escort.
Where from?
The C20XE made its debut in 1988 in the Astra GTE 16v, Vauxhall's answer to the Escort RS Turbo. And quite an answer it was too, producing at least 20bhp more than the turbo'd CVH. Granted it cornered like warehouse but we don't care about that, because it was powering the wrong wheels anyway! The 'valver' was based on GM's highly successful 2.0 eight-valve, J-series Family one, four banger but with a fair amount of involvement from the boys at Cosworth. The XE got an upgraded bottom end, possibly designed with a thought given to Group A and Group N rallying. They did more than just design the cylinder head though; for the first two years of its life Cosworth cast and machined the early cylinder heads until 1990, when GM switched to a production item.
The early engine is regarded as the best one to have with its Cosworth cast cylinder head. It's a well documented fact that the GM heads can go porous, so the head of choice tends to be earlier one. There are many different cures/repairs for the porosity issue, some being better than others. The engine changed over to ECOTEC in '94 (affectionately codenamed: every component on this engine crap), which can still make good power but it's not the one that you want.
If you're in a scrapyard you'll need to be looking for a Mk2 Astra GTE, Mk3 Cavalier GSi or late model SRi or an early Calibra 16v. The basic rule of thumb is that you need to be buying an engine with an L-shaped spark plug cover in the rocker cover. If it's straight, it's no good. And if it's that Cosworth head you're after, it's identifiable by the 'coscast' stamp and the fact that (unlike the GM unit), they don't have a core plug-style casting on either end of the head. TheC20XE is getting a bit thin on the ground these days, but an interesting alternative is the 'baby' XE found in an early Corsa GSi. It's only a 1600, but believe it or not responds even better to simple mods than its larger capacity brother. Throttle bodies and an exhaust can take it up to 170bhp without breaking a sweat, plus it weighs a lot less.
Cylinder Head
Most engines have a cylinder head-mounting distributor. Not a problem in the front-wheel drive configuration as it sits over the gearbox. However once you have turned the engine around, the distributor ends up right where your bulkhead wants to be. Needless to say, it's got to come off. There are two ways of doing this, the easiest way is to buy a simple bolt-on blanking plate, but the ideal way to do it is to have the rear of the cylinder head machined flush to the rear of the cam cover and fit a simple blanking plug. This allows the engine to be mounted nearly an inch further back. You will also need to get the camshaft shortened to be the same length as the inlet cam and as the cam is lubricated by an oil way up the centre, you will need to bung it to stop it dribbling out of the end. This is easy and can be done with a ball bearing or simply tapping a thread into the end of the cam and screwing in bug. If you opt for performance cams, some of them come ready shortened with this conversion in mind.
The cylinder head also has a water outlet at the rear. Depending on what you are doing with your bulkhead you may need to have this pipe removed and a core plug fitted in its place. Some people say that this can cause over-heating although 'The Van' runs this set up and hasn't had any problems.
Sump
You have three choices of sump, the first is the Manta 1.8 alloy sump. Ideal for the Escort conversion as the Manta was rear-wheel drive and shares the same engine block. The Manta sump is designed to be mounted with a 7-degree tilt and thus works better with either the Manta gearbox or SBD's special bellhousing. You will also need the Manta oil pick up pipe too. The only problem with this is that they are rarer than us finishing a magazine on time and thus fetch a premium sum of money. You may also need to use a lowered rack mount crossmember to get the engine in the ultimate position. Yukspeed manufacture a big wing tin sump for this conversion which works best mounted flat, so for this you should use a straightforward vertical mount bellhousing.
If budget permits, dry sump is the ultimate route giving maximum clearance and ultimate performance, although this is really only needed for competition. While the sump is off, get a set of ARP rod bolts fitted, this will serve you in good stead and allow the engine to safely rev to 7750rpm rather than the 7250rpm it does in factory trim.
Clutch
If you are mounting your engine to a Manta gearbox, you can use the standard Vauxhall clutch. If you've decided to mate your XE to a Ford 'box you'll need a special clutch kit which uses a Vauxhall pressure plate and a modified centre plate with the correct splines for the Ford gearbox. This is available from SBD as a kit, along with a release fork suitable for the bellhousing.
Transmission
You have a couple of choices of cog swappers for this conversion. If you can find one, the Manta 1.8 five-speed unit will bolt straight to the back of the XE but it's a fairly bulky unit and will require tunnel mods. Most go down the route of buying a bellhousing specific for mounting a Ford gearbox behind a Vauxhall engine. SBD can supply you with either a vertical mount bellhousing or a 7-degree incline bellhousing. The choice depends largely upon the sump that you use, but it's generally thought that the engine was originally designed and mounted with a 7-degree tilt so for optimum lubrication, it's best to retain it.
The bellhousing will mount to either a Cortina/RS four-speed or a Type 9 five-speed unit, which will obviously fit in a standard tunnel at a squeeze. As a wild card, the Borg Warner T5 is probably the gearbox with ratios best suited to the XE and with an adapter plate, will fit, although the tunnel will need enlarging. One final noteworthy point is the fact that you will also need a spigot bearing, available from SBD. This sits in the rear of the crank and basically supports the gearbox input shaft.
Bodywork
Apart from those chassis mounts, you can actually slot an XE in the engine of an Escort with minimal work. Use a Ford gearbox in its standard position and mount the engine where it wants to sit. At worst you may need to trim up your bulkhead lip. Don't be fooled into thinking that this is the best route to take however. Do yourself a favour and fit a large gearbox tunnel and while you are there, raise the prop tunnel too. The reason for this is that crossmembers and sumps dictate the engine position in such a way that the gearbox tailshaft can end up pointed at the floor. With a raised tunnel you will be able to lift the back of the gearbox up into the tunnel and not worry about anything catching. Plus, when clutch change time arrives, you'll thank us for all that extra room.
Cooling
The XE doesn't run particularly hot and you could even get away with running a standard RS2000 radiator. We'd recommend opting for something a bit more substantial though, just to be safe. The plumbing can be a bit of a nightmare, depending on whether or not you are planning to keep the interior heater. There are no hose kits available as such but Samco produces a number of different shapes and sizes and so you will be able to fabricate something.
Engine Mounts
As a rule of thumb, the resting position of your engine is dictated by the position and type of your gearbox. There are World Cup crossmember engine mount kits available to buy, but for the sake of a small amount of welding, we'd advise going down the chassis mount route.
Sparks
As you have now removed the distributor you'll need something to send the sparks to the relevant places. Here you have a couple of options. The budget option is to buy a distributor mounting bracket similar to that found on the Manta. This will relocate the distributor to the front of the engine. It is then driven by a belt leading to a modified exhaust cam pulley.
The second is to bin the dizzy altogether. The valver operates with a crank trigger as standard, which gives you options for aftermarket management. When you buy the engine, make sure that it still has the crank sensor in it as these are quite pricey to buy new. SBD use MBE management with its throttle body and carb kits for this engine. However if money is tight, but you still wants to lose the dizzy, it's worth looking at a Megaspark or Gotech setup.
Hydraulics
Due to the inlet side of things now taking place on the driver's side of your Escort, the brake master cylinder is going to be in the way. You need to get yourself a bias pedal box from the likes of GRP4 Fabrications, which will relocate the cylinders to the inside of the car and the fluid reservoirs to the bulkhead. As it's highly likely that your Escort came with a cable clutch you can either retain this, or chose to convert to hydraulic with one of the necessary kits available from Burton Power.
Exhaust
The fact that it originally powered the wrong wheels (the front ones), means that the original exhaust manifold is no good for your Escort, which is also a blessing in disguise. When Cosworth designed the engine, it originally made 170bhp, but the company wanted an increase in low down torque and so reduced the exhaust manifold tube size. this in turn helped with emissions but reduced the overall power.
SBD sell two exhausts for the RWD conversion, a cheaper 'clubman' version which suits fairly standard engines on carbs. The more expensive special exhaust is the one to plump for as this has been developed for ultimate flow and can free up a lot of ponies. Your other option is to get one made, but make sure whoever does it knows what they are doing. There is no exhaust system on the market for this conversion, but providing it's got a 2.5" bore, you should be able to adapt an aftermarket one.
Induction
The standard, multi-point fuel injection setup is very bulky and actually can interfere with the engine mounts in rear-wheel drive format. It's not easy to tune and as such, not worth bothering with.
You have options though. First option is to go with carbs. Get yourself a manifold and ideally a pair of 45 Dellortos, although Webers will work fine. These will work in conjuction with an ignition-only ECU which utilises the standard crank trigger. SBD can supply a complete kit which comprises everything you need to get the car going and when combined with a decent exhaust manifold, gives you 180bhp without venturing inside the engine.
The ultimate choice is to go back to fuel injection but via throttle bodies. SBD does two types; parallel throttle bodies and tapered throttle bodies. The tapered bodies are the ones to go for as they give much better adjustability and airflow. At nearly two grand they are pricey, but when you consider that bolted on to a standard engine with a decent exhaust manifold, that XE can develop as much as 208bhp and remain 100% driveable, it's money well spent. The taper bodies also fit the Escort engine bay better. 'The Van' runs SBD's tapered throttle body kit and we can't fault them.
If you opt for fuel injection you will need a tank with a return fuel line fitted. You will also ideally need a swirl pot but definitely require a high pressure in-line fuel filter.
Power to the people
Let's face it, with this conversion you might have just doubled the amount of power under your right foot, so you're going to need to use your head and spend a few pennies on bringing the rest of the car up to scratch. Moving forwards at a greatly accelerated pace means that you need the reassurance of being able to slow down a bit quicker too. As it's an Escort, you've got a plethora of choices of brake upgrades. At a minimum go for Princess four-pots, but if you can afford the extra pennies, it's well worth investing in a big disc brake kit from the likes of Hi-Spec, AP or Wilwood.
The XE won't really trouble your rear English rear axle in a road car and so all you'll really need is an LSD to make it a bit more playful in the corners. If you are going to compete or looking for power figures in excess of about 230bhp, it might be worth investing an Atlas axle. Being as the valver is a high revver, the standard Type 9 won't last long behind it. So plan for a straight-cut gearset if you are aiming to raise the horsepower by a significant amount.
The bolting of an XE into your Escort will undoubtedly upset the purists when you open the bonnet, but you can always get a blank spark plug cover to confuse them. Like it or loathe it, the XE is a great engine and when slotted in an Escort, is huge amount of fun.
Thanks & Contact
A big thanks to SBD (020 8391 0121) for their help with this feature, your first port of call for advice and parts when attempting this conversion.
Reproduced with permission of Retro Ford magazine