I've done a cylinder head swap before so I knew what to expect. It's not that difficult a job, but you need to be confident about the cam belt and timing marks. Read the Haynes manual over and over for a few weeks before doing the job. If you're not that sure what to expect then go and dismantle an engine at a scrap yard. Or even just take a look, there's loads of headless engines at scrap yards.

I started the job at about 3pm on a Friday afternoon, worked until 10pm, started at 10am on Saturday and had it running by 4pm on the Saturday. That includes matching the inlet manifold to the head and fitting the valves. It was hard work, I didn't take too much time over anything.

Preparation is vital I went round Vauxhall and picked up new head gasket, inlet and exhaust gaskets, ten head bolts, stem oil seals and gasket sealant stuff. Also went to tool shop and bought a Dremel like hand held drill and some grinding tools and finally went to the motor factors and bought a massive roll of Blue Roll, some cheap oil and some better oil. A can or two of carb cleaner is useful, as is some wet and dry for gasket cleaning.

Sorry there are no pictures of this job, the camera was off for repair. Probably better anyway because I was under a bit of time pressure.

The basic principle of the job is easy - the inlet manifold and exhaust manifold, the timing belt and various connections have to be removed, then head bolts can be undone and the cam box and head taken off. It pays off to be cunning and leave as many items as possible partially assembled. I took the inlet manifold off complete with throttle body and pipes. On the exhaust side I disconnected the downpipe from the centre section so that I didn't need to undo the rusty manifold to downpipe bolts.

In my case I then spent some time grinding out the inlet ports on the head so that they matched my enlarged manifold. Firstly I placed the new gasket on the inlet manifold flange, in the correct position. The manifold runners were about 1mm bigger radius than the gasket. I used the old technique of a hammer to tap the gasket so that the edge of the runners cut the correct profile into the gasket. I had to be careful not to round the manifold edge off. Next I sat the gasket on the cyliner head inlet face. I aligned it using the stud holes. I then drew round the gasket with a marker pen. Then the fun started with the grinder. I found the best tips to use were the grit paper round a drum sort. They only lasted a few minutes but they removed a lot of material. I bought 50 of them so I wasn't running short in a hurry. This was a very satisfying job. I enlarged the ports and tapered the new profile into the modified head profile. I didn't go overboard - the taper lasted about 10-15mm.

Next I removed the head.The actual head bolts are not that tight, I used a long arm extension socket, they came undone easily enough. It's always an interesting moment when you get the head off and look at the condition of the pistons, bores and valves. Everything looked healthy enough to me. A thin layer of light and dark grey on the valves and pistons but nothing serious.

The new head had new valves that had already been lapped to the head. All I had to do was transfer the tappets and springs over from the old head and fit the new valve stem seals and valves. This is a pretty straighforward job. You have to own a valve spring compression tool. I bought one for under £20 from my local tool shop. It can be a bit scarey, because when the valve spring is compressed, the valve is released by gently prising two collet halves out of the upper spring washer. If the compressor let go at this moment then the collets would be lost. I didn't want that happening. The actual stem seals are easy to remove and fit. They just push onto the head. I used a socket and hammer to tap them on.

The gasket surface on the block has to be cleaned up prior to refitting the head. Care must be taken not to drop crud down into the oil and water ways. I used a blunt screwdriver as a scraper, so carb cleaner, loads of rag and also a bit of wet and dry on one akward bit. I did drop some crud down into the block, so I changed the oil and filter pretty quickly after getting the engine running.

Reassambly was pretty straightforward. Follow the correct order for head bolt tightening. I fitted a new cam belt whilst I was at it. I didn't touch the water pump, 9/10 the new belt will be tensioned ok. If you adjust the pump then it's best to remove it and fit a new seal. Otherwise they tend to leak.

I used new manifold studs and Copper nuts, it's worth getting some of these because a few will end up knackered in the removal process.

Finally the time came for the big switch on. I filled the engine with oil and refilled the cooling system. Water started leaking out of the end of the engine by the thermostat housing. I assumed that the thermostat seal was to blame because I'd had to use some sealnt there. So I put the hose pipe into the coolant header bottle and tried starting the engine anyway. It turned over, coughed and then ran. It was a bit lumpy though. After about 30 seconds it stopped. So I had another go. This time it coughed then there was a minor bang. Not good. I looked at the exhaust pipe. Water was dripping out! WTF? My immediate thought was that the head gasket was leaking water. Next I looked back in the engine bay. Eh? Water was coming out the air filter! Then the obvious occured to me: the throttle body has three pipes connected to it. Oil breather, water in and water out. What if I crossed two of those over? Water would be running straight into the inlet manifold. Sure enough. Sorted that out and it ran fine. I was very worried about the bang though. That would have been the engine trying to compress water. Which doesn't. You can wreck and engine that way.

Next I looked at the oil. It was a mayo colour. That'll be water in the oil then. So I went off and bought two bottles of cheap oil and one decent one. I drained the engine out twice and finally filled with the semi decent oil. That'll be four bottles of oil in one day then. More than most people do in a year! Oh well, I was just pleased it worked.