Fitting a 2 litre motor in a Corsa B

Seeing as this is a question that gets asked quite regularly, I thought I’d make a complete post of it. Please note that this is NOT the only way to do it – it is merely a description of how we did it with my UTE, and thus far it all seems to be holding up really well even with loads of abuse. I will also mention other techniques for certain issues that have been done with success.

How it all started

I saw a Monza CD 16v for sale in rather shabby condition for R9000. The engine had picked up a bearing knock that needed to be fixed. The gearbox was fine, Engine management was stock. Absolutely perfect for what I had in mind. I decided to purchase this vehicle, take what I need and sell the rest of what was left from that vehicle.

Engine

As mentioned the engine had a bearing knock and an overhaul was promptly done. New bearings, rings, water pump, valve stem seals, cam belt tensioners etc. were done. The motor had actually been overhauled quite recently before the bearing knock, so it worked out fairly inexpensive to overhaul the engine. The engine was left standard.

Now it is quite clear that the engine will not just quickly slip in and bolt onto the existing mountings – some small changes are needed. The front engine mounting on the driver’s side needs to be custom made. On the engine block there are 2 sets of mounting holes – one set sits above the crank angle sensor, the other set below. We opted to use the lower set, just so much simpler. We drew up templates from cardboard as to how the mounting should look, and took this to a steel merchant that could cut it to our specifications. The main plate was given a 90 deg bend rather than a welded joint ensuring more strength. Lots of supports were welded onto it to ensure it can’t collapse or break. After completion of this mounting we assessed that it might be a bit of overkill, but at least we knew it would not break. See picture below,

The rubber mounting that bolts into the body was taken in to be filled with poly-urethane – we were firmly of the belief that the standard rubber mounting would not handle the extra weight and power. Due to the mounting being completely filled with poly-urethane, it was extremely rigid – great for the engine staying where it should, but not so good if you have a couple of rattles… I would suggest having the poly-mounting done a little bit less aggressively.

Gearbox

We used the F20 gearbox that came with the Monza. This is effectively just a straight swop. The mountings are the same on the F13, F16, F18, F20. We had to make a small modification onto the back mounting with an angle grinder to allow it to fit onto the F20 gearbox. I have heard of people fitting a 15mm spacer, but then the linkages need to be extended by 15mm as well - sounds like a lot of effort for something that might not be needed....

Drive shafts

We used the drive shafts and CV’s from the Monza. They are a fair bit stronger than those that come off the Corsa. They are the exact same length. Obviously this would not just fit onto the Corsa’s hubs, so we used the Monza’s hubs. The wheel bearing used is the exact same as that of a Golf II. This bearing has the exact same outer diameter as the Corsa’s. The Monza’s hub then needs to be machined down to the inner diameter of the new wheel bearing.

Oil cooler

This was such a cool and simple addition. We had to drill one hole to mount the Monza’s oil cooler, the other hole was already there. Just ensure that the pipes are well clear of the wheel on full lock to left. Check it again should you ever change your mags or tyres.

Brakes

It is highly advisable to add bigger brakes to the vehicle. We used those from the Monza with new Alfa disks and brake pads. The callipers are a straight swop.

Powercap

The normal SFI box for the C20XE would not fit inside the engine bay. The powercap we used was a home made piece – maybe not as effective as the more expensive pieces, but it works fine for starters.

Water hoses

We used a couple of hoses from the Monza, but most hoses stay the same. The radiator used was the original one which is the smallest one available for the Corsa. The ideal would be to use the radiator that comes from Corsa’s fitted with air-con.

Engine fan

The plastic cowling needed a bit of modification to accommodate the fairly large exhaust manifold. We also fitted a 12” fan to the front of the radiator with a toggle switch just in case a bit of extra cooling is needed. It has never been needed yet – the car never runs hot. The fan switch used in the radiator is a 92 - 87 switch. The water temperature sender used comes from the Corsa to ensure correct calibration on the heat gauge on the cluster.

Airbox and air filter

We decided that the standard Corsa airbox would be too restrictive. The Monza’s airbox would not fit, so we went the route of a cone filter and a custom housing.

Engine management

We used the standard ECU and loom from the Monza.

Suspension

Nothing was changed, except for the torsion bar being mowed forward a touch to accommodate the 4-1 Viper branch which takes up a fair amount of space.

Exhaust

A stainless steel 57mm freeflow exhaust was fitted, with one small Cowley silencer and one HUGE Cowley silencer to try and keep it fairly quiet.

Fuel pump relay

The fuel pump relay on the Monza’s loom sends current to the fuel pump. Wiring was done from the relay in the engine bay to the pump’s wiring inside the cabin next to the driver’s seat.

Coil

We used the coil from the Monza. Obviously a feed needed to be added from the ignition to power it

Fuel pump and fuel lines

This was my greatest headache. Initially we used the standard Corsa fuel pump, but found that the motor was suffering from severe fuel starvation at higher revs under load. I replaced the pump with an external pump and tried again. Same problem – so suffice to say the original fuel pump was not the problem. I purchased an adjustable fuel pressure regulator and that solved the problem. I noticed that with the fuel pressure set at 2.5 bar (which is the standard for XE motors) the starvation remains. At around 3.8 bar the hesitation is gone, but it does cause over-fuelling in normal driving conditions. I am convinced that the fuel lines are a bit too thin for the application, so I will replace them with 8mm lines and report back.

Other options for some of the above:

Gearbox

The F13 gearbox can be used. It does however entail changes to the flywheel and clutch – will add more info should I receive it. The benefit of using the F13 is that no changes need to be made to the drive shafts, CV’s, hubs or bearings. Down side is that the gearbox might not be as strong as the bigger gearbox options, and the high engine revs when driving on the freeway.

N/A TUNED explained how to do the flywheel conversion to keep the F13 gearbox: "well ill be able to help u guys with th f13 gearbox,clutch,flywheel. works as follows. you would need a 1600 fly and the 2.0l fly, the pitch of the holes are the same but wont fit. take it to the engineering and ask them to slot the holes to the outside and to make the center hole the same as the 2.0l center hole to center the fly if you don't do that will have a BIG vibration. once done can use 1600 fly,clutch.pressure plate. so hows that for doing a fly conversion"

Drive shafts

You only need to make changes here if you change the gearbox. You can use several options here. For instance, you can use the standard Corsa drive shafts and just have an inner CV made up at a reputable CV shop to fit into the new gearbox. Another option is to use the bigger drive shafts and have an outer CV made up to fit into the Corsa hub.

Engine management

Again there are many options here. You can use an aftermarket system, just remember that there are then Dyno costs involved. I do not have all the info on it yet, but I have heard of the management and loom from the 2l16v Ecotech motor being used on the C20XE with great success – bonus is that there is no airflow meter needed in that setup. I have also heard of the normal loom and Motronic box from the Corsa being used with success on the 2l 8v setup.

My costs incurred in the process (Estimates and round offs – I can’t remember it all):

Purchase of Monza R 9000
Overhaul of engine R 3000
Manufacture of engine mounting R 400
Poly-urethane of mounting R 140
Engineering R 300
Wheel bearings R 200
New disks and pads R 500
Cone filter, housing and piping R 600
Powercap R 200
Exhaust (Branch came with the car) R 1500
Adjustable fuel pressure regulator R 550
Fitment Check with Pat – I forgot

I have of course recovered some of my costs by the sale of the Monza, my old engine, gearbox, ECU, loom, branch, drive shafts etc.

A HUGE thanks to Patrick from Highway Performance (072 376 1311) who did the conversion (With me as his spanner-boy). Thanks for all the help Danny, ACID, Allan O, ANi, Fuzz, Pass-Chill, Joka…. the list goes on… Also thanks to everybody who gave any tips, advice or parts for this project to happen.

PLEASE excuse any mistakes or omissions I may have made in this post, let’s just call it a work in progress. Hope it helps.

Thanks to Dodging from the Opel Owners Club forum.

Max Auto and its members do not accept any liability or responsibility for any damages or malfunction resulting from use of this tip. Consult a mechanic or other qualified person before attempting any changes to your vehicle.