|DISCLAIMER: The information in these documents are a collection from experience (friends or myself), magazine articles, mailing lists and Internet web sites etc. So don't take these as 100% correct gospel, hence I don't take any responsibility for any of these guides.|
|Difficulty Rating: Very hard, will need expert advice and tools.|
Download printable Adobe Acrobat file (300K)
Download zipped web page version (400K)
Created: 9th March 2002
Fitting a 'big block' 2L engine into a Vauxhall Nova / Corsa-A chassis.
Overall scope of the engine conversion:
This is a guide on how to fit the larger 'big block' 2L engines into the tiny Vauxhall Nova / Opel Corsa-A chassis. It isn't an easy job and it may take several weeks if not months to do the job yourself. Many years ago this engine modification was rare and difficult to do which meant only specialist garages were able to carry out the job. Typically this modification will cost you several thousands of pounds in parts and labour.
As the years rolled by, more adventurous people thought "I can do that", and behold people started to do their own DIY engine conversions. This guide shows you the most common of engine conversions of the Nova/Corsa-A. How to fit a 2L (8v or 16v) engine.
Please note that this is ONLY a GUIDE on how to do it. Depending on what engine you have fitted and engine mounts etc., there are different characteristics on getting the job done. Also the owners of Topbuzz Web Site have NOT done this modification themselves, this guide is a collection of peoples past experience and information from other web sites around the world with their permission. A 'collection' of information if you will in one location.
|1.1: Types of engine to use|
Common engines fitted are the following. One point to note, the BHP figures are quoted by the original car, i.e. a Calibra with a C20XE is 150BHP as standard. Now if you put that into a light chassis, i.e. the Nova, the BHP will be much higher. So even the lowest powered 2L 8v engine, is still going to have a hell of a poke to it ;-)
2L 8v SOHC engines:
Found in Calibra's, Astra's and Cavaliers. The 20SEH are found in the Cavalier SRi's (higher insurance). All engines are injection fuelled and all have 5-speed gearboxes. Only very early models did not have a CAT fitted, otherwise expect all of them to have a CAT installed.
2L 16v DOHC engines:
Found in Calibra's, Astra GTE's and Cavalier's. Standard gearbox was the F20 which was 5-speed. Only very early models did not have a CAT fitted, otherwise expect all of them to have a CAT installed.
All Turbo models had 4x4 transmission, hence the 6-speed gearbox will need to be modified to 2WD to fit in a Nova plus the gear linkage, bulkhead and rear engine mount needs to be modified. A conversion kit can be purchased for this, but a F20 will equally fit onto a C20LET engine.
Early C20XE engines were fitted with mechanical distributors (Motronic 2.5). While on later engines they were replaced with a DIS (Distributor-less Ignition System) unit, but still called C20XE (Motronic 2.8). All engines are injection fuelled. The Turbo engines are basically a normal C20XE with a Turbo bolted on (Motronic 2.7). However they do have a different compression ratio plus the piston and parts of the cam are made of stronger material and the the cast iron exhaust manifold is VERY heavy.
2L 16v DOHC Ecotec engines:
Found in later Calibra's, Vectra's and Astra MK3 and MK4's. The Ecotec series engines are the cousin to the C20XE engines. All engines are injection fuelled and have 5-speed gearboxes. These engines were engineered to meet higher emission standards (hence the reduction in BHP) and all have a CAT fitted as standard.
|Points to consider:|
V5 or Log Book:
Engine bay strengthening:
Note: Nova GTE and GSi models had thicker gauge metal in the engine bay and strengthening already applied to the suspension turrets. However, these cars still need strengthening.
Both methods have
their ups and downs, Option 1 is neater, but getting the crank pulley
off the crank is difficult, most of the time the heads of the bolt strip
and you end up drilling the rest out. Also the extra wheel is there to
help resident vibration as it spins up to speed. The other option requires
a boxed in section, this can be a pain to do, cutting the chassis rail
is difficult as the metal is ½ an inch thick. Usw heavy gauge metal
for the boxed in section.
SFi air box:
You should have the following items taken out
New engine preparation:
|Engine Bay Preparation:|
With the engine bay empty, inspect the area for rust and bad corrosion etc. Treat the area, sand down and weld up the engine bay. If you have bought the plates, then use these. As you have the engine out and the room to play about with, you might as well do as much as you can here.
The engine mounts will also need to be moved or modified. Again the offside engine mounts needs moving down 1.5 inches or buy a ready made one.
The area where the alienator pulley will go will need to be modified. As explained before either smack the area in so that the pulley will clear or cut out the section and weld in a box area. This will have to be judged upon where exactly you need to do this work. Either trial fit the engine in place and gauge where the work will be required. Only the engine can be lowered down from above, if the gearbox is still attached, then you need to put the engine in from under the car (its the only way it will fit).
The following areas need welding (stitch or seam)
Once all the welding is done, clean the area and seal on the joints with silicon sealant and repaint the engine bay.
|New 2L Engine:|
You should already
have the new engine, make sure you have the following parts/items:
It would be ideal if the donor engine has been seen and heard running before fitting it into the car.
|Fitting New 2L Engine:|
If the gearbox is attached to the engine, then the engine can only be mounted in the Nova from underneath. Hence you need to drop the Nova on top of the engine.
The reason for the modifications is that the engine doesn't sit right in the engine bay, it will be too high and you'll need a bulge in the bonnet. The rear one needs modification to allow it to site correctly above the wheels and not be tilted over. However, of moving and welding the engine mounts scare you, you can buy ready made engine mounts from some rally shops. Costs between £60 - £110, depending on quality and amount of plates supplied.
You will need the bracket for the rear engine mount or you can modify the box. The gearbox mount for the nova box has two holes and the new box will have three holes. You can either use a bracket from car-quip or you can modify the box , but be careful not to strip the thread on the box. It is probably best to fit it after the engine is in.
The rear mounts need
cutting and welding with the bottom section moved to the right by 10mm.
Note: Before installation
of the engine the clutch pipes from the cabin needs to be bent down by
45 degrees and across to the passenger side by 30 degrees, this makes
the clutch easier to push. Also the heater matrix pipes, the right one
needs to be shortened by about 8mm to clear the inlet manifold.
The other option is to retain the 2L drive shafts and modify the Nova hub so that it accepts 2L outer CV joints.
|Procedure to fit the new 2L engine:|
Now you have to put your new engine in the small engine bay. Start by fitting the drives side engine mount to the engine. Using the nova selector on the new box and rotate the white joint though 180 degrees. Mount the passenger side engine mount to the car making sure the nut a washer are facing toward the front of the car, don't tighten it as it will need adjusting.
Now lift the engine over the engine bay and get some mates to help you lower it slowly in. It will fit don't worry. When the gearbox gets level with the passenger side mount, put in the three 15mm bolts. Once that mount is attached, lower the engine, shouldn't be to far now.
When in get to the right point put in the drivers side engine mount bolts. Finally put the rear engine mount onto the gearbox and connect it to the car. Tighten all the bolts up. The engine should now stay in the car unaided.
At this stage if not done all the brakes and suspension can be uprated now and the petrol tank needs be changed for an injection one if you haven't already got one.
Fit these following parts in the listed order to avoid difficulty later,
When mounting the ECU, it needs to be located inside the cabin of the car, the loom will need to be fed around the driver side turret and into the cabin, then mounted either on top of or underneath the drivers side parcel shelf.
Depending on what engine mounts you have used will mean whether or not the gear linkage will need to be modified. If PVD engine mounts are used, for the rear all they did was get a standard mount and weld a slab of metal in to space the mount out a bit, this had the side-effect to moving the linkage pivot mount over by the same thickness of the slab of metal. If you have this problem then the linkage will need to be extended after the pivot by 5mm (weld an extra length of bar on the end), also extend the top arm by the exact same amount. This method also have a hidden side effect, it gives you slight quick-shift.
Because the Nova is so small fitting the standard air-box is hard and is very tight. Another option is to fit a Cone air filter, this looks a lot better and if set up correct to give you more power. There is a downside to this, the extra air intake can cause a problem known as 'Kangarooing', and this is where the car stutters when decelerating, doing a modification to the rocker cover can rectify this problem. This modification known as the breather mod helps relieve excess crank pressure and stop the problem. This modification be found on the MIG site. Also when the rocker cover is off spray it the same colour as the car!
There is not much
space between the drivers side turret and the engine block to fit the
air intake pipe, using some cutters take as much of the support rubber
as you need and smooth off with a dermal multi with a grinding disc on
it. This gives just enough room to fit the pipe in. Be careful not to
squash the pipe.
Q) What's the best Nova's donor car to start off with?
Our advice would be the GTE or GSi model, because of the following
Q) What does 'big block' mean?
Its the term used to express the bottom block of the engine. The size was very common in the Vauxhall range, in fact many of the time the head was simply the only deferent part. With this building block, different engines were created. So 'big block' is the crank half of the engine, which exists on the bigger larger Vauxhall engines (but the V6 are bigger of course).
Q) can I use my existing Nova gearbox on the new engine?
No, it won't fit. Even if you did the drive shafts would be difficult on getting to work too. Need some special one offs. More hassle than its worth.
Q) Do I need to upgrade the radiator?
The standard Nova GTE or GSi radiators are fine for the job, plus they fit straight in!
Q) I've fitted the engine but my anti-roll bar hits the manifold/sump!
You need spacers underneath the tie bar mounts. These can be bought ready mad. They simply lower the bar down towards the ground, hence creating a small clearance area round the sump or downpipe of the manifold.
Q) How do I find what engine I have or what type of 2L engine I can get?
The engine number is stamped on the block itself.
Q) What comes with the CarQuip mounts?
CarQuip mount is £50 + del + vat and includes offside mount and gearbox spacers but not bolts
Q) Where can I buy the strengthening kit?
For the chassis strengthening kit you go to Harry Hockley http://www.hh-ms.com . But note that this kit is for rallying purposes and may be over the top for a road car. ASW and Novatech may also be able to supply you a more worth while kit that does the job. Welding a strengthening kit is more convenient than seam or stitch welding.
Also, pro-tec do some
stuff for the conversion too...
Q) Where can I buy a ready made exhaust manifold to mate with my Nova one?
Q) Where can I get the drive shafts from?
Novatech only supply the drive shafts which fit my existing outer Nova CV joints to Astra inner CV joints for £220 (a pair).
Also, pro-tec do some
stuff for the conversion too...
links to web sites here.
|Example 2L Gallery:|
Showing examples of the larger 'big block' 2L engine fitted in Novas and Corsa-A's
Topbuzz Web site would like to thank the following people for giving me permission to use some of the pictures and content to help construct this guide.
|home | search | contacts | © | topbuzz.co.uk|