Hi,
Think I have a problem with the timing belt on my 93 Cosworth. About 12 months ago the timing belt on my cosworth failed on the motorway and bent all the valves in the head. It turned out that 4 teeth had sheared off the belt, at the time this was put down to a dodge pair of alloy vernier pulleys which seemed to of worn quite badly.

I had the car repaired and fitted a new pair of quaife steel vernier pulleys (the peg type pulleys) a new tensioner and a gates timing belt. I removed the timing belt this weekend as I'm going to be changing the cams over Christmas and found that the belt was starting to fray at the the root of the teeth (where teeth join the belt).

This belt has only covered approx 8K in the last year and I'm a bit concerned that it has started to fray at the root of the teeth. If you bend the belt back on itself you can see that the teeth have started to crack where they join the belt, it all sounds a bit to familiar to the problem I had 12 months ago!!

The quaife pulleys do not appear to of worn apart from the black coating on the teeth been worn off and the tensioner has no play in it. I checked that the tensioner had been tensioned clockwise and it had so the belt isn't touching the thermostat housing.

Does anyone have any idea what could be causing this or where I should start looking?
Is it possible for the crank timing belt pulley or the dizzy pulley to wear and cause this problem?
Any help would be appreciated as I don't want to be changing my belt every 8K miles if I can help it.

P.s. Just out of interest how often do you lot change the timing belt on your Cosworth's?

 

its normal to see some cracking between teeth after use tbh,

i change mine once a year, as its a half hour job, and i abuse my motor lol

 

what make belt is it??

 

Belt is made by Gates and says Powergrip on it. I think I brought it from Burton's if I remember correctly.

 

Do you know roughly how many miles you cover between changes?

 

I remember being shown a damaged cossie timing belt on a trip up to NMS quite some time ago.

It turns out that the belt teeth had failed because the cog on the crank had a split in it, front to rear, that opened up the gap between a couple of the cog teeth and strained the belt teeth.

Might be worth you investigating a bit further.

 

Thanks, will have a look at the crank cog, may change it anyway just in case will have to see how much Ford charge for a new one.

 

about 20k max.

 

I do tensioners/belts on every one of our family's cars every 25,000 reasoning it's cheaper than a rebuild.
The last belt was QH and never had a problem with belts in 25 years.
As said though the micro cracks are just in the rubber surface on the teeth, and does not affect it's strength.
tabetha

 

Removed the crank shaft timing belt pulley on my car yesterday and found that the timing belt pulley had worn quite badly. The radius on the edge of the pulley teeth had completly gone and is now just a sharp edge so think I need to change this pulley as well.

Anyone know if Ford still sell these and how much they are?