I've been reading through the cam belt guides in FAQ and I'm wondering why you would slacken the cam pulley bolts when changing the belt?

I thought the idea of having the 3 timing holes was to lock everything in position so that everything is aligned properly. By slackening the cam pulley bolts , are you not allowing everything to move??

I have just been looking inlet the cam pulley from a spare cylinder head I have and noticed that the lug with the timing hole can actually turn a certain amount within the pulley. The exhaust pulley on that head has no f**king timing hole at all?

If the timing hole can move independently of the pulley then My very limited understanding of how timing holes work is now thoroughly confused. Can someone help?

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Phase 2 Blaze GTi6

PS3 - Black Ops 2

Engine crane for hire Renfrewshire

There are two types of pulley too,early one with three bolts you slacken to allow the movement to tension belt,and later type which you need to slacken the big bolt in the centre of pulley to allow movement to tension belt.

The exhaust cam your on about has got the small timing locking pin lug missing,look at the rear of the inlet cam and you will see what you have lost

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Red GTB1756 powered Fabia VRS daily driver,LBSC Gti6 eater........

Mac1 ZR R1 kit car build in progress.

What could cause the timing to go out of sync when driving?

My mates car became a tapper at a trackday a couple of weeks ago. We think this may have been caused by dropping into a low gear without equalising the revs but what would have moved if this was the cause?

The cam belt remained intact. Again I'm just trying to understand the process.

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Phase 2 Blaze GTi6

PS3 - Black Ops 2

Engine crane for hire Renfrewshire

It's strange because it happened at a knockhill reverse evening the other week. The same thing happened to my engine ( with him driving)last year ( although I thought it was the bottom end at the time), also on a reverse day.

We have been running track days at knockhill with 6 engined cars for years without ever having this issue.

Then we attended 3 reverse days and killed 2 engines. The only thing we could think off was that we are travelling faster going down the straight into the hairpin on a reverse day than you would be going clockwise. Brakes fade quicker and he uses engine braking more.

Before this I thought the belt had to snap to feck the timing, but 2 engines have now gone out of sync without the belt snapping. too much of a coincidence IMO .

I am now nervous of attending a reverse day until sussing out what is happening.

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Phase 2 Blaze GTi6

PS3 - Black Ops 2

Engine crane for hire Renfrewshire

When the 1st engine let go the belt was lose ( installed before my ownership) and we assumed it had jumped a tooth.

But the 2nd engine the belt was probably slightly too tight if anything.

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Phase 2 Blaze GTi6

PS3 - Black Ops 2

Engine crane for hire Renfrewshire