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Discussion Starter · #1 ·
does anyone have a guide for the conversion of a redtop into corsa b,whats req etc.or where i can find a guide? thank u

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Guide to fitting an xe into a corsa

Engine choice

Any of the 20xe engines will do, unlike the nova there is no requirement to run the single vee alternator pulleys, the multirib stuff works perfectly well.

Obviously you need to first remove the original engine as per Haynes or other service manual.

Gearbox choice

Any of the big block gearboxes will suffice; they are all plenty strong enough for an xe engine. Choose based on cost, availability and ratios, but the normal f20 box from cavs, callys etc is ideal IME


Before you fit the engine you need to remove the starting and charging loom from the original corsa engine and fit it to the xe. This makes the wiring really easy as now you have two completely separate discrete looms. Once the engine is in the car you simply plug the original corsa starting and charging loom back into the corsa car loom.

When you removed the corsa engine loom (with the engine) you should have been left with a square 9 pin plug in the drivers side foot well. The complete xe loom remains on the engine throughout and simply feed through the bulkhead in the same place as the original corsa loom. On the end of the xe loom you have 3 plugs which will need to be cut off, some of these will be joined to the 9-pin plug and some simply left. (I cut the plug off the corsa loom before I discarded it and used this on the end of the xe loom so that I could still easily unplug it for removal. (Easier to do this before you fit it to the car IME)

Wiring colours are as follows:

XE loom

Green - revcounter feed, wire to green on corsa plug (some corsas may not have this wire, in which case use a bullet connector and run a green wire to the rear of the clocks if you wish to fit a set with a revcounter.

Brown/Blue - ECU light, match to corsa plug

Brown/White - Diagnostics, match to corsa plug

Brown/Yellow - Diagnostics, match to corsa plug

Blue/red (thick) - Fuel pump feed, match to corsa plug

Blue - Coolant temp sensor feed for dash clocks, match to plug

Red/White - Autobox, unused in conversion

Red/Blue (thin) - electronic speedo feed, match to corsa plug

Red (large) - Battery +ve

Black (thin) - Battery ?ve I moved this inside and matched it to the corsa plug
Black/green - Aircon, unused in conversion

I put some effort into rewiring the loom, I moved the permanent live feed to inside the car at the 9 pin plug instead of to the battery, the A/B fuelling plug is in there as well etc, but this isn?t necessary.

Fuel relay block remains as is.

Engine mounts

Mounts are commonly available on ebay, or from Chris Astley (Rallyman on MIG) The simplest is fitting to a 1.2 8v corsa where you just need the drop mount. This bolts between the engine block and the original rubber on the wing.

For 16v corsa models you will also need a wing mount which iirc takes a calibra rubber. This bolts into 4 pretapped holes on the corsa inner wing (16v models don?t have a rubber here like the 8v ones.

The front gearbox mount is easy; just use the original corsa one.

The rear gearbox mount sometimes needs a spacer, sometimes doesn?t. It appears to be Vauxhalls manufacturing tolerances, as there is to rhyme or reason to it. I undid the bolts and fitted the under car rubber as close to the box as possible, then fitted the engine and measured the gap. Turned out I needed a 12mm spacer, which was simply made from some flat bar. Again these are easily available if you don?t run to home engineering.

Engine mounts can be stiffened by filling the gaps with polyeurathane sealant

Gear linkage

The gear linkage needs to be extended buy the same amount as your gearbox spacer if you have one. Insert new metal into the curved section being sure to keep the alignment. I also extended to top bar using a piece of threaded rod and some small rose joints.

The gearbox end of the linkage was not suitable on the corsa, so I removed it and fitted a nova end, then simply inverted the white plastic block. You could make the corsa end work; I just didn?t feel it was worth it as I had a spare nova linkage anyway.

Coolant hoses

I used the original 1.2 8v radiator, I?m not sure about the 16v and diesel models? For the 1.2 8v rad you need to acquire a 1.0 12v top hose for the right hand side of the rad (thermostat housing)

The bottom hose and header tank hose are retained from the corsa.

Ideally you want a rear coolant gallery from an astra, but in reality with some careful bodging you can use the cavalier/calibra one too.

The long hose from the cylinder head (under the dizzy) runs to the heater matrix. I found I had to shorten this, so I used some copper plumbing pipe joiners with the solder removed as these had a ridge to stop the pipe blowing off. I simply cut it on the long straight run and shortened it.

This leaves you with two outlets on the coolant gallery, one goes to the heater matrix and one to the header tank. The heater matrix pipe comes from the corsa, but the header tank pipe had to be made up from copper pipe and the bends from the discarded pipes.

I also took this opportunity to dispose of the rusty spring clips and fit new stainless jubilee clips in their place.

Fuel supply

If you have a single point injected corsa your current fuel pump will not supply sufficient pressure for the new engine. A pump from a multipoint corsa must therefore be used, and transferred into the spi carrier in the top of the tank.

In the engine bay, you should have the original rubber pipes coming off the fuel rail from the donor car. Sleeve these over the plastic pipes in the corsa and secure them. I used two proper fuel clips here, DO NOT use jubilee clips as they will leak.


I reused the standard air box in my conversion. Come filters aren?t always a good idea, especially in a cramped engine bay. Space is tight, with the clips on the air box just touching the cam cover on the engine.

The easiest way is to use an ecotec 2.0 induction pipe and a converter plate for the TB (again available from ebay/mig) But powercaps can also be used. The SFI box WILL NOT fit. Bulkhead modification is again a suck it and see job, but the powercap will almost certainly need it.

The ecotec bend is joined to the xe afm and then use the xe hose to the airbox as it contains the air temp sensor.


The standard xe manifold is the most suitable really, anything 4-1 wont leave sufficient ground clearance under the collector.

You will need to lower the ARB a bit if you wish to keep it (I did, I got a 23mm one off a diesel combo van) I?m running a 2mm spacer between the crossmember and the tie bar mounts, and using Vauxhall 8v head bolts cut down. Then an additional 20mm between the tie bar and the arb.

I went to my local kwik fit and nabbed a flexi section off something complete with the cone joint for the manifold and just mated this to my exhaust system, there are a multitude of ways to connect it up, but all require a welder and some patience!

Driveshafts and Hubs

Few options here:

22 spline smallblock shafts:

You can run a set of these from a TD or gsi corsa with the original outer hubs, bearings and small cv joints, using an mk2 cavalier 1.6 big block inner cv joint to mate it to the box, simple, quick, but obviously leaves you with vulnerable outer cv?s

Big block shafts with machined hubs:

Machined hubs are available widely to fit into the std corsa bearings in the steering knuckle. You then use the big block driveshafts complete with outer cvs. This is ok, but there have been instances where these hubs have failed due to being too thin around the ends of the splines. Many people run these with success however.

Big block shafts with machined knuckles:

This is the best solution IME and involves machining out the steering knuckle to accept a larger bearing allowing you to retain the std hub dimensions. The knuckle should be carefully bored to 68mm by a machine shop and the circlip grooves deepened. There is also a small ridge on the hubs which should be removed to prevent them fouling the new bearings. Golf mk2 1988 synchro 4x4 rear wheel bearings can now be fitted.

When I fitted mine I dropped the car on the ground before tightening the hub nuts and check the cv plunge. On the drivers side I had 5mm or so, but the passenger side was tight, so the driveshaft was removed and shortened. To do this I removed the worthless bevelled section from the end (7mm or so) and then machined a new groove 7mm further up (at the inner end of the splines) This makes fitting cv?s a little tricky, but how often do you change them?

The equal length shaft setup from the calibra will also fit complete and IME is one of the best modifications on a powerful corsa.

Speedo feed

All the f20 boxes are mechanical drive, so you will need the mechanical fitting with the small gearwheel on it in the box from the donor car.

If your corsa has a cable speedo, simply attach the cable to the fitting on the box, however if it is electric things are a little more involved. All electric drive corsa boxes afaik use an f28 style electric pickup, which cant be used wit the f20 box. If you have this issue, use an early c14se corsa sender, which simply screw to the fitting on the box and requires an earth, ign live and the feed to the dash.

Suspension and brakes

Obviously these will need to be upgraded suitably to match the higher top speed and extra engine weight. I run calibra turbo front brakes, standard rear drums and braided lines, and spax adjustable suspension. I would also advise fitting a hefty front anti roll bar such as the diesel one mentioned earlier.


On a side note I hope it is obvious that some aspects of servicing are best undertaken in a preventative manner with the engine out of the car. I changed the timing belt and rollers, spark plugs, clutch, etc before fitting and the oil and water afterwards.

Coppied from Vauxsport!

2 Posts
is there anyone near bridgend south wales who would fancy sorting out the wireing on my corsa b for me its frying my head will pay expenses for the help

6 Posts
The site it's offline for me, can you give me a helping hand?

I wanted a little help with the conversion, i'm using a C20LET and i want to find a engine mount that fits perfecly. I found a photo with a good one and the other one it's with my engine.
Can you help me? Thanks.
This is the one i search:

This is what i have:
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