What is this modified pulley?
How does it look, any pics?

Group Buy on modified Pulleys! I have a cam belt change coming up soon, an ideal time to fitted a modified pulley!

G

Definitly a good idea, would need to be perfectly machined and balanced though i would imagine. I would recommend it for anyone changing belts soon, it isn't a nice experience!

Didn't Flea say: "It's a bitter pill to swallow when a belt lets go and nukes the engine. Been there, done that. In fact, I am finally going to try and put an end to this misery. I have on my own car, but I will roll this out now as it's a "preventable" disaster."?

Sounds like he already has an answer to this problem?

Yes I have, and the modified pulley is not it as I still managed to bend 20 valves using one!

i threw away 3 modded pulleys a few months back, simply lack of demand.

They can be made at low cost, but they dont guarantee cambelt protection if the aux belt fails, they just offer more protection.

Agree with rog.

I had one of Barbz pulleys, but its just a pulley with an outter lip added maybe 3-4cm max. It will reduce the chance of taking it out, but its not a prevention of this.

Only way you could prevent fully would be with a enclosed section to the pulley, but the cover wouldnt allow this i don't think?

Ross

I was thinking of a plate next to the cam belt cover to stop it happening.
I really need to look into it to see what's possible!

The ps belt doesnt snap, it derails.

Fitting guides (giant washers) to the pulleys is a better idea, is not impossible to do either.

The acceleration in the lower gears (especially on modded coupes) is so savage that the belt cannot hold on and slips off.

I'm not all THAT technical, but what would be involved in changing the setup to a chain? (You may start laughing now.)

It was a very hard acceleration where it went. Big flame and then BOOM!

This is why you need to get it rebuilt, just listen to it http://www.youtube.com/watch?v=077ua2Tpt9c

Cheers Paul, makes the ball ache seem worth it!

No probs Matt the offer is still there I'll make the tea

and i said ill make the coffe

I found a pic of the pulley in my Coupé folder .

Personally the first thing I did was to cut off that TDC marker which is attached to the timing belt cover and sticks out over the belt. At least it gives it more of a chance for the belt to fly past the cover rather than rip it off .

Baz

I'll clean up the mess

Why laugh, Klaas? It's a very sensible question and one I've considered off and on for years... bear in mind the alleged reason for using belts is quietness from the engine, but I'd be surprised if it wasn't also cheaper. I've been thinking about the 16 with the more fragile belt, of course.

You'd need to replace the cam pulleys with toothed wheels to suit the chain, the tensioner idler, the crank pulley, and anything else it goes around - water pump, balance shafts etc. (I'm not that familiar with the 20).

You'd probably need to replace the tensioner assembly anyway with some sort of hydraulic device, and you'd have to arrange some lubrication for the chain. A sneaky designer might come up with some way to drive the tensioner from oil pressure and drip feed onto the chain - but you'd also need to scavenge the oil back again, so that might need a better seal on the cam cover unless you wanted a total loss system.

The system would probably be narrower than either the 16 or 20 belt, which would give scope for better packaging (the cam chain on the similarly sized Nissan 1.8 turbo I used to own wasn't much thicker than a bicycle chain, though it did require changing due to stretch over a hundred k or so).

Snag is, there's a lot of expensive engineering to manage before you get it working. Not impossible, but probably not financially feasible unless you've got one of the last three engines in existence, or you just happened to have an engineering works in your back yard. It's not an amateur project, I fear.

But if anyone comes up with a DIY kit for the 16, I'd like one, please! (And for the 20vt, when/if I get one.)

You've hit the nail on the head Neil, it would be the lubrication of the chain that could present the biggest issue. Trying to get an oil seal around the crank and ensure an oil tight seal around the cover would be incredibly difficult.

There will be a way of reducing the risk of the belt debris being dragged into the cam belt assembly and I would love to see a decent solution to the problem because it happens too frequently and is definitely a design flaw that should never have been allowed off the drawing board.

A chain would be noisy, and as stan says a pain to lubericate.

The pulley and tensioner just need guiding.

I did start this a couple of years back, but nobody wanted to shell out +£50 for modded bits, so i gave up.

£50? I'll sponsor you.

Bike chain doesn't need as much lubrication? Also, it should be possible to have a piece of plastic moulded between aux and cambelt. Maybe something else... we're all looking at protecting the cambelt, but wouldn't it be possible to machine the pistons to make sure the valves don't touch?

This might also help:

Considering the cost of a cambelt replacement is £400+ anyway, an extra £50 to save this kind of damage is a no-brainer IMO, I'd pay it every time..

it's not just the belt - if the aux belt goes then it a few quid to fix.

If i goes into the cambelt when it goes then it's time for a top end rebuild + some new valves, AND and new cambelt + aux belt.....a lot more than £400.

£50 , I never heard about that. I can't believe that people were not keen at that price.

If there was a 99% certain way to eliminate this problem I would happily pay several times that figure.

I remember having an Escort RS 2000 and im sure that had a chain.

I wonder if a grease chamber could be made,so that the chain would pass through it,collecting grease as it goes.
It could have a grease nipple as a top up device.
Or is it all to agricultural?
I worked on Catapillars for years you see.

My Alfa 164 was chain driven

How was it lubricated Paul?

Haha, sorry that made me laugh. Childish side of me I think!

Not sure to be honest Joe didn't have the car long as it got wrote off.