One of the most popular motorsport engines and one of the most popular choices for kit cars.
To identify if the engine you are looking at is an XE, the cam cover will have an L-Shaped spark plug cover on the cam cover. Even though the engine is referred to as a red top on later engines the plug cover was black.
Vauxhall XE Conversion for RWD
The full name of the XE is 20XE and was first installed in the MK2 Astra GTE followed by the Cavalier MK3 GSI, Cavalier SRi and some early Calibras. The engine wasn’t in production for long before it was modified with the new code being C20XE. It was modified for emission reasons and power dropped from 157bhp to 150bhp. The last of the line engines from 1992 an on were distributor less and used Motronic 2.8 ignition. This engine was designated as theC20XE LN.TheC20XE LNused cast pistons instead of the forged pistons used in the original 20XE and C20XE. However the block on theC20XE LNis actually stronger than the block used for the earlier engines.
Vauxhall XE Conversion for RWD
Generally these engines are very reliable so high mileages shouldn’t be a problem.
Vauxhall XE Conversion for RWD – Coscast
Cosworth helped design the head and up until 1990 they also cast the heads. The later heads were made by a different company and these heads had problems with porosity which can show the same symptoms as head gasket failure, fortunately the problem is solvable. The Coscast head can be identified with an oval Coscast logo mounted just below the exhaust port of number 2 cylinder.
Vauxhall XE Conversion for RWD – Sump
The Manta sump can be used but the XE was designed to be used at 7degrees and if you are keeping this angel then the Manta sump will need to be modified. However the XE engine has been mounted vertically without problems. For ultimate reliability a dry sump set up would be the way to go.
Vauxhall XE Conversion for RWD – Ignition
For RWD applications the distributor ends up next to the bulk head, if this is a problem the easiest solution would be to go for an aftermarket ECU. SBD have a lit specifically to overcome this problem. If you’re going for a stand alone ECU then you may as well get throttle bodies at the same time for a solid 200bhp.
Vauxhall XE Conversion for RWD – Gearbox
Again a Manta 1.8 gearbox can be used but it is a little big especially for MK1 Escorts. T5s are OK but they are built for Torque not rpm so the Type 9 gearbox is the most popular choice. QED and RWD Motorsport offer suitable bellhousings. These bellhousings are also available in vertical and 7 degree installations.
Vauxhall XE Conversion for RWD – Clutch
Again an off-the-shelf solution is available when using the Type 9 which uses the Ford centre plate and Vauxhall pressure plate and release fork
Vauxhall XE Conversion for RWD – Cooling
There is a water outlet that points to the bulkhead on longitudinal mounted engine. This can be blanked off or if you need the heat it will need to be rerouted. It’s rumored that blanking this off causes overheating issues but it is down to the removal of the elbow section in the coolant circuit below the thermostat.
Vauxhall XE Conversion for RWD – Exhaust
The original manifold on the Astra and Cavalier are good, with a bit of cutting and shutting it can be made to work on a RWD application. The C20XE header is not a good starting point.
Vauxhall XE Conversion for RWD – Tuning
Turboing is not normally carried out because the C20LET is so readily available. With stand alone engine management and throttle bodies 290bhp is possible. QED even offer an alloy block that is 19kg lighter.