SWAP 20XE Paso a Paso

El cambio del motor original por otro de 2 litros de cilindrada se está convirtiendo en una modificación bastante popular entrelos propietarios de Corsa B/Tigra A . Para realizar esta conversión con éxito necesitaremos de la ayuda de unos kits de adaptación de la nueva mecánica y de la nueva caja de cambios que encontraremos en los Astra F GSI 16v, Kadett GSI 16v y Calibra 16v.

La conversión puede realizarse sin problemas con el kit 710011 de Mtech si se tienen en cuenta los siguientes pasos que citamos a continuación.

1. The anti-rollbar will foul the new engine’s exhaust, so it will need to be removed and refitted with MTech alloy blocks to create more clearance. The anti-rollbar is fitted to the Tiebars of the Corsa with M8 bolts .
2. The Corsa’s standard front suspension must be uprated with Spax or Koni dampers and you can fit the original Corsa springs of a 1.6L 16V model. The front end of the car drops about 30mm because the new engine and gearbox put more weight on the front axle. But you can also fit a lower spring kit, to lower the car more then 30mm. These parts can be fitted following the engine conversion. Spring compression tools will be required to remove the old springs and fit the new ones.
3. The rear suspension do not have to be uprated with adjustable or uprated dampers (eg. Koni or Spax) because the rear of the car has no extra weight. The rear suspension must only be uprated with lowering springs, so the car will be lowered at the rear as well as the front. (because of the engine). When fitting these springs, support the rear of the car on axle stands. Unbolt both of the old dampers and the rear arms will drop down.
4. The front brakes should be uprated with a Calibra Turbo 4-stud conversion or 256mm vented discs from the Cavalier or Astra 16V. All big brakes from any 2.0L Astra, Cavalier or Calibra will fitt onto the MTech hubs without modification. (these special hubs are for fitting big cv-joints) The brakes can be fitted after the engine conversion, but are essential – the Corsa’s standard brakes are insufficient.
5. Replace the front wheel hubs with uprated units from M-Tech. Remove the front hubs complete with discs, callipers and hub carrier. You will need a hydraulic press to remove the old hub and fit the new one. Fit new wheel bearings and oil seals.
6. Remove any soundproofing in the engine bay and the air filter housing to create some extra space. The standard air filter housing is usually clipped into position. Remove the wipers (13mm nuts) followed by the two scuttle panel covers retained with crosshead screws.
7. Use a junior hacksaw to cut the right heater matrix pipe at the first ridge (about 10mm from the end of the pipe). This has to be cut to give more room and make it easier to refit the coolant pipe later.
8. You will need to modify the bulkhead as shown in the MTech conversion guide to fit a powercap. This powercap replaces the SFI-box on top of the induction of C20XE engines.
9. For UK only: Re-route the brake pipes to create more space for the plenum chamber. Fit the pipes further back into the modified area of the bulkhead. You may be able to reshape the brake pipes, but avoid kinking them. Make new pipes if you damage them.
10. You will need to extent the idle speed control pipe from the 2.0L engine to the power cap or use a complete new hose from MTech.
11. Fit the MTech bodywork engine mount, which is fitted on the offside inner wing. Body work type-1 models can use a standard engine mounting. The photo here shows the standard mount being removed.
12. For those who want to strenghten the chassis: The MTech strengthening kit (550001 or 550002) can be fitted to help provide additional strengthening to the crossmembers. This is essential when fitting a Turbo engine, but advisory for C20XE and C20NE engines. Full instructions are provided on where to fit the strengthening panels. You’ll need to weld the strengthening panels into position.
13. The in-tank fuel pump for SPI (cars with mono point injection as standart) models needs to be changed for the MPI unit (multi point). The fuel pump sits under the rear seat base. Disconnect the fuel pipes and electrical plug, then knock out a retaining ring with a hammer and chisel and twist the pump to remove it.
14. Use a radiator from a 1.4L or 1.6L Corsa. These radiators have enough cooling capasity to cool the 2.0L engine. MTech recomends a MTech cool running fan switch and a cool running 2.0L thermostat. These parts keep your engine 10 degrees below normal running themperature. Mtech also have complete cooling hose kits to make fitting the cooling hoses a lot easier. (720080)
15. If you have a UK 1.0 12v or 1.2 16v Corsa, the throttle cable can be used. For European cars, remove the old cable (unhook it front the pedal and pull it through the bulkhead from the engine bay) and fit one of a Calibra 16V. The Astra and Cavalier GSI’s cable can also be used.
16. A twin outlet header tank must be used. The second outlet is required to feed coolant to the inlet manifold to keep it cool. This type of header tank is fitted as standard to the 16v Corsas.
17. The gear linkage must be extended by 15mm to enable the Corsa’s gear lever to connect to the gearbox. If you don’t fancy cutting and welding, MTech produce a short shift kit that bolts straight on and saves you the hassle. (170008)
18. When you’ve found a two-litre engine, always change the timing belt, pulleys, tensioner, water pump and sump gasket (if leaking). Only use V-belt pulleys, not ribbed as they will foul the chassis. If the timing belt tensioner has a metal pulley, remove its spring (it can fall off).
19. Remove the bottom lugs and side lugs on the F16 or F20 gearbox for the two-litre engine. These are not required and their removal will provide additional clearance. Use an angle grinder to remove them. Use a file to remove any sharp edges from cutting.
20. Fit the standard Corsa rear gearbox mount with an aluminium adaptor from MTech. Fit it to the underside of the bodywork with two 15 bolts. The mount uses a 15mm bolt and 16mm nut. It’s bolted to the gearbox with a new 19mm bolt and the MTech adaptor.
21. Connect the modified gear linkage, as covered in part 1 (step 17). The standard gear linkage can be modified, or a short shift from MTech can be bought and fitted instead. The linkage is connected with one 13mm bolt
22. Fit the nearside gearbox mount. This is a standard Corsa mount, fitted to the nearside inner wing panelwork with two 15mm bolts and a rubber mount. It’s also fitted to the side of the gearbox with three 15mm bolts.
23. At the front of the engine, fit a MTech engine mount. The bodywork mount is fitted to the inner wing with four 13mm bolts. The engine mount is fitted to the side of the engine block with three15mm bolts. The two mounts are fitted together with two 15mm bolts.
24. If your Corsa has power steering, the original pump cannot be re-used. Use a C20XE pump or a C20NE pump with a MTech mounting bracket. (720008) The pump pivots on the bracket with a long 13mm bolt. The adaptor plate is fitted to the engine block with three 15mm bolts.
25. Working away from the Corsa, build up the MTech driveshafts, 2.0L-CV joints, front suspension and brakes. Fit them onto the car. Use MTech driveshafts, which have the correct outer an inner splines. We covered details on brake and suspension upgrades in part 1.
26. Fit the radiator. This must be a three-outlet radiator from a 1.4 or 1.6 Corsa. Such a radiator has enough cooling capacity to cool the two-litre engine. Do not cut corners with a smaller radiator or a used one that’s damaged.
27. Measure up and fit the coolant hoses. On the offside of the radiator, a short hose runs to an outlet on the cylinder head. The other large outlet on the radiator is connected to a plastic pipe that runs underneath the inlet manifold. MTech has complete cooling hoses kits that fit straight on a Corsa-B C20XE conversion if you don't want to make new cooling hoses yourselve.
28. Fit a twin outlet header tank from a 16v Corsa. If a water heated inlet manifold is fitted, the hosing from this is connected to the smaller outlet on the header tank. The larger outlet is connected to the top nearside of the radiator.
29. Fit a standard exhaust manifold from the C20XE engine and secure with six 13mm nuts and six 13mm bolts. Don’t fully fit it yet as it may need modifying later for the Lambda sensor and exhaust system.
30. If your exhaust system or manifold isn’t fitted with a lambda sensor, cut one out of an exhaust leaving the surrounding tubing as shown here. Drill a hole in a suitable place on the exhaust manifold and weld the lambda sensor in position.
31. With the exhaust manifold fitted, measure up and trial fit an exhaust system. If you intend to re-use the original system, measure where to cut it. A catalytic converter should be fitted unless the engine is pre-1993.
32. Refit the front anti-rollbar and use MTech fitting kit to provide more space for the exhaust manifold . This is fitted with extended 13mm nuts and bolts for the aluminium blocks and standard 13mm nuts and bolts at the ends of the anti-rollbar.
33. Before fitting a standard Corsa cooling fan and housing, reposition the electrical connector plug so it doesn’t foul a cooling pipe when fitted. To do this, undo three 10mm nuts at the rear of the housing, rotate the motor and refit them.
34. Fit and connect the fuel pipes, making sure they don’t foul any moving parts. The fuel return pipe will need shortening before connecting it to the XE’s fuel injection system.
35. Due to the limited space in the engine bay, a MTech Power Cap should be fitted onto the standard throttle body. First, remove the four standard studs on the throttle body. Fit the Power Cap with four long 10mm bolts (supplied with the MTech Power Cap).
36. Fit the standard Vauxhall C20XE fuel pump relay and connect it to the appropriate plug in the XE wiring loom. The same part of the loom has a long wire with ring connector. This is a ECU live and needs to be connected to the positive battery terminal
37. Fit the C20Xe air flow meter onto the Power Cap, then route some hosing to the MTech 'green' air filter. There should be plenty of space forward of the timing cover, where the standard air filter box is fitted, to be able to position the new Green open air filter.
38. Use the ECU supplied with your XE engine . Route the XE’s engine loom into the cab and connect it to the Corsa’s loom. New connecting plugs will need to be fitted, but the wires can be matched according to their colours.
39. Inside the engine bay, route the injector loom. On the end of the loom are four connectors. The larger two go to the distributor and coil pack. The smallest (green coloured) isn’t used (rev counter sensor) and the other needs to be connected to a switched live.
40. Connect the Corsa’s speedo cable to the XE’s gearbox. The cable should fit without modification. Also fit the throttle cable