Zetec S (Sigma) cambelt snapped - options?

[Kitchski]

Hi all, my brothers 2001 Fiesta Zetec S just shat it's cambelt tensioner all over the road, causing the belt to basically get jammed and snap. Theres now no compression and the usual issues.
I've had one go on my g/f's Saxo VTS and managed to buy a set of valves, as the guides were ok and change them over. New cambelt kit, head gasket set etc and it was all tickety-boo again.

I've heard these Zetec's are a bit more involved though. How strong are the guides? And whats this about no timing marks to time it up with? I've not even collected the car to have a look at yet, just trying to weigh the options up. Replacement heads/engines seem to be big bucks (£250 +....I'm used to French £50 engines!) so a repair would be the more cost effective option provided the bottom end is ok, and then I have the advantage of knowing I've got new gaskets etc.
I've also been told the valve clearances are shimmed? Is this a specialist job to remove and replace valves?

I'm actually a partsman for Ford, so getting the parts at a good price isn't a problem. I've also noticed that Focus' 1.6 seems to have the same engine, are the heads interchangable?

Many thanks to anyone who can educate me before I go throwing his money and my time around!


Cheers

[neiljohnson]

Before you buy anything take the head off as ive seen these engines destroy a piston when the valves hit, if the pistons look okay then it should be ok with just valves its not hard to do the clearances if you have a calculator

[Kitchski]

Not even worth going through the motions of fiting a new belt and timing it up to see if it runs really is it? So get that head off before I do anything you say?

[neiljohnson]

Kitchski said:

Not even worth going through the motions of fiting a new belt and timing it up to see if it runs really is it? So get that head off before I do anything you say?

in my expiriance it will have hit they run a very tight tolerance so not much room for error im afraid.
As for timing it the tools to do it are around a £10 from laser consists of a bar & a pin

[Kitchski]

Cheers. Being that the belt's slipped etc, if I were to buy said kit, lock the cams in place once I'd stripped it all down, lock the crank in place before undoing the crank bolt (and keeping it marked up where it goes) would I be able to bolt it back up and set the timing that way? I keep getting told the crank is a floating type, so if you undo the crank bolt the pulley can slips either way, losing your timing in the process.

[neiljohnson]

Kitchski said:

Cheers. Being that the belt's slipped etc, if I were to buy said kit, lock the cams in place once I'd stripped it all down, lock the crank in place before undoing the crank bolt (and keeping it marked up where it goes) would I be able to bolt it back up and set the timing that way? I keep getting told the crank is a floating type, so if you undo the crank bolt the pulley can slips either way, losing your timing in the process.

The bottom end is floating the pin goes in the back of the block locks the crank (dont try to undo the crank bolt using the pin it is not strong enough & will bend) as the crank is locked it does not matter what the pully does

[Kitchski]

Whipped the head off yesterday....8 very bent valves, 16 very slightly bent valves and the bottom end is fine, so new head it is!

Cheers

[neiljohnson]

Kitchski said:

Whipped the head off yesterday....8 very bent valves, 16 very slightly bent valves and the bottom end is fine, so new head it is!

Cheers

Thats good news the valve guide are pretty tuff though so may be worth just putting new valves in it make sure that you get the right length though as there are differant types!

[Kitchski]

Something about single groove and triple groove for the collets? And they're shimmed too aren't they? I work at a Ford dealer so getting the shims will be ok, but the valves are £14 each!

I was debating buying another head and just switching it, but thinking about it I may be better off changing the valves in this one, when you weigh up costs, carriage etc on a second hand one.

Had a nightmare getting it off though, took ages. The parts microfishe at work only shows 4 bolts on the manifold to downpipe joint

[neiljohnson]

Kitchski said:

Something about single groove and triple groove for the collets? And they're shimmed too aren't they? I work at a Ford dealer so getting the shims will be ok, but the valves are £14 each!

I was debating buying another head and just switching it, but thinking about it I may be better off changing the valves in this one, when you weigh up costs, carriage etc on a second hand one.

Had a nightmare getting it off though, took ages. The parts microfishe at work only shows 4 bolts on the manifold to downpipe joint

Buy the valves aftermarket @ £4 each yes there are differant collet fitments but have also come across differant lengths, i have done valves on these using the original shims & have never had a problem

You will need to buy/ borrow the timing tool (a bar & a pin) to time it up right when its back together also replace the crank bolt as its designed to stretch when fitted so an old one wont secure properly.

[ianqv]

Kitchski said:

Whipped the head off yesterday....8 very bent valves, 16 very slightly bent valves and the bottom end is fine, so new head it is!

Cheers

Sadly the engine is now a scrapper!
Even "if" the pistons look ok - they won't be!
It all depends how long you want to keep the car for! if it is a case of get it running and sell it, replacing the valves etc will get it running.
If you are planning on keeping it... you could just be opening a can of worms!
When the valves hit the pistons it's not just a small dent that goes in the top of them. many things are effected i.e pistons shape, small and big end bearings and don't forget your con rods!!

It may be worth while pricing up a re-man unit or an engine from the breakers.

[Kitchski]

Neil: Good tip, I'll get a new bolt from work. Found the timing kits at £11 at the local Maccess so I'll just buy one of those.

Ian: Cheers for your input. If I'm being honest, I've had about 3 or 4 belts go on cars I've had over the years (all at slow engine speeds/idling, including this Fiesta). One cracked a piston, so the engine just got changed, but all the others just bent the valves, with my Saxo VTS most recently leaving a sizeable chunk the piston top and bending 12 valves (one cylinder escaped completely!). All I've ever done is replace the valves and I've done another 10k miles or so in the Saxo with no problems, as with my other cars.

The pistons aren't even dented in the Fiesta, just slightly chipped on the inlet side. I filled the bores with petrol last night at TDC and went back this morning....the level has dropped a mm or two, and fairly evenly across all four. I'm fairly happy to de-coke the head, fit new valves & seals and rebuild it with that block. I'm not saying you're wrong or discounting your advice mate; if I'd never done it before I would probably heed your warnings! But I'll carry on as I know how and when it all goes belly up I'll come back and you can laugh at me!

Cheers