Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Cam timing belt thickness

I am considering changing the cam drive belt , but before launching in I thought I would check the collective knowledge on what constitutes a worn belt.
There doesn’t appear to be anything specific in the S&S owners guide and workshop manuals.
Using callipers the land between teeth on mine is 0.12mm or 50 thou.
I am presuming it’s the land which wears, eventually resulting in failure.
I would be interested if anyone has comparative data.
This belt has been on mine from new , 12K miles later.
Thanks
Graham

S&S says to check every 10K miles. If you have the spacers installed on the front cover that will greatly improved the life of the belt as heat is its main enemy. Mine is going on 30K miles and aside from the small buildup of fibers, which I wipe out, it looks good. It should be good for 50K miles when a rebuild of the motor would be a good idea anyway.

The rear belt should be good for 100K miles unless a rock finds its way in there and holes it.

These things are tough!

Several things have an impact on belt life. Time certainly is one, which is especially critical if you do not drive much. A belt that sits starts to stiffen into a position. So I would rather have a 2 year old 20k miles belt over a ten year old belt with only 2k miles.

Visual inspection (unless there is something obvious) is a crap shoot (IMHO). That 10 year old belt with only 2k will look good.... and then you get to rebuild an engine.

Think of it like tires.... would you run a 20 year old tire with only 2k miles?

Exactly - check what ? Next to useless in itself.

On tyres you can check the tread depth.
On this belt I am proposing a measurement of the thickness of the belt in one of the valleys between the teeth could form the basis of a wear indication.
My new one hasnt arrived yet to publish the 'as new' thickness , but a I think a list of mileages and thicknesses would be very useful to get a wear profile over time , so get measuring please !

On tyres measuring the tread depth is only one issue. Tyre manufacturers advise that tyres will get hard and reduce grip after 5 years. They can also crack. There are no consumer devices to check tyre harness nor consumer advice of what any measurement should be.

At times you have to accept the manufacturers recommendations on life of components .

Rather that direct that other owners measure their belts and report back to you, can I suggest that you contact the manufacturer for further advice on inspecting the belt.

The manufacturer is the only official source of advice and you may well find that your chosen method of inspection may or may not be the procedure used by the manufacturers in diagnosing belt condition.

Good point Eddie - will do.

I think the manual says 30,000 miles which was what I ran min to and it was fine when it came off. You can usually tell when the protective layer has worn off on the toothed side and you can feel the filament. Changing it is easy enough and if it were to break the values won't hit the piston so no damage will occur it will just stop

Will the valves interfere with pistons if the Stage 2 Cam upgrade if the belt fails?

No, the 569 cams are non interference, same as the standard cams

Thanks Chris.