I need to replace the cylinder head on my 1.3 spi engine, and i was just wondering if a GT head would alter the compression ratio to give better performance?

ALso is this a big job to do? I'm a bit of a retard but i will have some helping hands around.

The are the same head, so it won't inprove the performance. Although using the GT cam would.

the combustion chamber is in the pistons so you'd have to change the bottom end to get GT compression.

heads are all the same, only difference is G40 which has sodium filled exhaust valves to deal with extra heat.

Would it be easier to swap the head or the whole engine???

Swapping the head would be easier, but once you've got the stage of pulling the head off you only really need to unbolt the gearbox and engine mounts to pull the block out. Slot in a GT block and head and there you go, even on the spi system it should make a difference.

Well I'm planning a GT or G40 conversion further down the line, so the current work is to keep the car alive until then. Anyone got a spare cylinder head for sale?

And any advice or tips for doing the job? I know i will need to replace the head gasket when it comes off, but do i need to do anything else? I'm guessing i'll need to do an oil and filter change, and drain all the fuel out too.

Sounding like a bigger and bigger job every time!

You're supposed to change the head bolts because they stretch when you torque them up apparently. I didn't and I'm fine and so are a few others. A new timing belt is a good idea. I wouldn't say you need to drain all the fuel out though, when I changed my throttle body there was a couple of drips from one of the unions but nothing else. You don't need to change the oil, but again you may as well.

So basically follow the haynes and remove everything that gets in the way, unbolt the head, swap the gasket over and put new head on, maybe use new bolts and torque them up, then replace all the shit i removed to get to it. Almost sounds more difficult than a straight engine swap lol.

Where can i get a new head though?

Leeds is full of Polo engines, you're just not looking hard enough.

Your method sounds good You'll want new exhaust and inlet manifold gaskets as well probably. For a head I haven't a clue, you might find a local breakers has one. Find a late Mk2 Polo, you'll probably find the engine is quite low mileage and the car has just rusted to pieces.

haha good call bout the mk2 toby spanish build quality...

And yes yeha very true, though surprisingly my conscience does feel a little bad about ripping somones bonnet off and stealing the head in the night...

I'll find one! Just need to organise a work party of people who know what they're doing now!

best off leaving the exhaust manifold attached to the engine and seperate it from the down pipe. I wouldn't bother replacing the inlet manifold gasket unless it is knackered, they have a pretty easy life.

EDIT - although having said that, I suppose it'll cost you more to get buy the exhaust manifold from the scrappers as well. If you do remove it you'll deinately need a new exhaust manifold gasket and new studs, not expensive though. At least a couple of the studs will break but they're usually pretty easy to get out with some vise-grips.

Fuck this is turning into a proper ballache - i thought the head would just come off in my ignorance, but i wil have to remove both fannymolds?

I hate being a mechanical retard - it thougt it would just be unbolt head, replace gasket and bolt on new head.

Anyone care to walk me thru exactly whats required?!

The manifolds are bolted to the head, so you need to pull them off if you're going to be changing the head. This is what I did when I did my head gasket.

1) Remove airbox, throttle body, any other connectors etc

2) Mark up the sprockets and pull off the cambelt

3) Remove inlet manifold

4) Remove exhaust manifold (well, unbolt it and support it from the downpipe)

5) Pull off rocker cover, unbolt the head (I loosened the bolts in the torquing up order, not sure whether you need to or not)

6) Wiggle the head about to break the seal and lift it off.

In the style of Haynes, refitting is the reverse of removal. You should clean up the mating surfaces between the head and the block, and in a perfectly ideal world, deck the block and skim the head. Slip on the new head gasket, put it all back together.

ONe more retard question then... Deck the block and skim the head - whats that mean, and how?

Sorry for being such a n00b and thanks for your patient replies, but the only way i'm gona learn this is by asking then doing!

Shame you don't live nearer toby, i'd willingly supply you with large amounts of beer to lend a hand!

skimming the head is when an engineer makes sure the head is perfectly flat. if it isnt flat you wont ever be able to mate the head/block together properly.

costs about £30 from most places.

It was skimmed when it had the head gasket changed last time, in september. It will have done a couple of thousand miles since then though... This jobs getting more and more involved!