Is the 8v an 'interference' design?

[Chris-White]

since this topic comes out quite often, and someone on here MUST have a digi engine in there shed,

disconnect the cambelt and rotate the engine to tdc. Then rotate the camshaft. If theres any resistance before it goes all the way round, we have our answer.

[Ben Lessani]

It is not interferance when standard. When I was changing the stem seals on mine I was happilly rotating the crank with cam in place (with valves full open).

The problem arises, as said, when your at high revs, its a bit different to turning an engine over by hand - the components are at the limit of their clearances. Combine this with an agressive cam and you'll certainly see engine damage.

Original specs say its Non-Interferance, but some people have bent valves - but they tend to never mention the conditions.

[danny_p]

i've had belt go while pulling silly revs,   no piston or valve damage,

on modifyed engines it is possible,  aftermarket cams and skimming head reduces clearance,             if a modifyed 8v dose do piston valve contact as the valves are square on to the piston a LOT of damage is done.   

[jezza16v]

Thanks all for your advice. It turns out the belt was changed at 52k in 1999.......? Now done 110k, probably perished now. I think I'll make it my first job as soon as I get it home. 

[Gambit]

do you want me to change your name to jezza8v?

[jezza16v]

 
No thanks, it will serve to remind me to think ahead more, sort of like a tattoo of an old girlfriend or ex wife...
Who knows, I might even find myself another 16v one day? 

[sidecarphil]

why not change it anyway

for the cost of a new belt and a couple of hours work it is better for piece of mind !!!!

maybe i just like wasting money !!!!!

[Ben Lessani]

Couple hours? The timing belt can be swapped out in about 15 minutes on a MK2 - easy peasy

[danny_p]

15mins is about right,   unless the allen bolts round out on  the lower pully 

[jezza16v]

I've done a driver and couple of 16v before no probs, (16v is much easier imo as less to line up) especially when the old belt is still there, takes me more than 15min though as I like to clean everything up as I go. It will be my first job when I get it home and into the garage.......I don't really want to be doing it on someone else's drive.........I remember those allen bolts on the lower pulley, a real pig if they're rusted in or someone's chewed them up before......