Timing Belt

Likely OEM, just been on the car so long that the marks are no longer visible. Nothing nefarious here...

 

+1

Note new belt with markings and note a used belt with rubbed off markings.

This tells me that your belt probably stayed on longer than the recommended usage therefore rubbed off all markings.
Do you know how many miles between belt service before your major was done?
Here are some photos from Birdman Ferrari that backs up this theory!
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login

 

Maybe it was, maybe not...Then again, with the 348 engine, that's one long, long belt doing far too much! The wear factor will be greater than a 3x8 or BB.

Great question, as there's a lot a junk out there being pedaled as OE. I've yet to see a knock-off timing belt, as the original ones are just not that expensive to begin with.

 

I just replaced one of my belts for a leaking cam seal with a new Dayco from Ricambi. It had only been a year since I had done a complete service with the same belts and about 1600 miles and the markings were fairly worn though still legible. I don't think you have anything to worry about.

 

The real question is does anyone know or have heard of a timing belt snapping off? It could skip a tooth or two therefore bending your valves but do you know how hard it is to break/cut a timing belt? 3-5 years or 30k miles is recommendation for belt service.

A timing belt is a transmission belt made from elastomers, having a flat outer surface with a number of teeth on the internal surface, widely used in internal combustion engines to control the valve timing. The belts are generally made from rubber with high tensile fibers, such as Kevlar or fiberglass, running through it. However, rubber's poor resistance to high temperatures has led to the development of timing belts made from highly saturated nitrile (HSN) that deliver significant resistance to high temperatures. Initially, the belts were designed with trapezoidal teeth, which suffered from high tooth wear rates. This has led to the development of curved teeth, which last longer and run quieter.

Here is a great write-up I found about Ferrari Timing Belts.
If your Ferrari was built since 1974, it is likely equipped with timing belts to operate the engine’s valves.
Ferrari has issued specific instructions regarding the periodic replacement of these belts to avoid engine damage. This is because Ferrari engines are “interference engines”, meaning that if the valves were to become “out-of-time” due to a drive belt failure, insufficient clearance exists between the open valves and the pistons to avoid mechanical contact. In simple terms, this means that if a timing belt fails, the pistons will strike the valves, bending them and also inflicting damage to the piston crowns.

To avoid this possibility, the periodic replacement of these belts is strongly recommended. Initially, published replacement intervals were based solely on mileage. Later, these recommendations were revised to include a time interval as well. This change was the result of incidences where belts had failed on vehicles with minimal mileage, but significant age. A Ferrari is typically used for pleasure driving and not daily transport. Consequently, infrequent use introduces an age issue with the belts. As belts age, dry-out, or become subjected to oil leaks, their performance is compromised. As stated earlier,
should a belt fail due to these problems, severe engine damage will result. The typical failure mode of a timing belt is sheared “teeth”, which
then cause the associated camshafts to become incorrectly timed. This means valves are open at the wrong time, when a piston is
reaching the top of its travel. Ultimately the pistons strike the open valves bending them. Repair to the engine at this stage involves
replacement of the valves, and possibly valve guides and pistons. The belt failure event is extremely quick during engine operation,
and therefore no corrective action such as stopping the engine can be performed in time to prevent the damage.

Furthermore, the compromised belt “teeth” are usually impossible to detect during preventative maintenance inspections.
As a result, the recommendation to periodically replace timing belts is used.
Image Unavailable, Please Login

 

Yes, it has happened a bunch of times, including mine (previous to my ownership). There was extensive damage to one cylinder head.

Also, there are several threads to support timing belt failures as well.

 

Hi Wade, so the belts were cut in two or was it the bearings/pulleys gave way and broken fence sheared the belts? Interesting to know how these things fail.

Thanks for sharing.

 

Mike, it was reported that "a belt broke and fortunately it was at a stop light". The work order shows a "cam belt kit with bearings", however, the cause of the belt failure wasn't determined.

BTW, this event occurred in 2002 which was before Ferrari issued their 3/30,000 document. At the time, the car had only 21464 miles, well under the 60,000 miles replacement interval as per the Owners Manual.

Here's post from the other thread...

Here's the entire thread - "How often to change 328's timing belts?"
http://www.ferrarichat.com/forum/showthread.php?t=293315

 

Nobody really knows the correct answer, the new assumption is, the belt breaks because of old, or worn tensioners. When the tensioner is worn, or the grease is dried they seize, and the belt then snaps ...hence ,the belts look like failure.

Personally, I have gonE over 7 yrs and have been fine. The key is monthly use , start ups, small drives but constant. This keeps everything lubricated, and the belts from forming , and then tensioners working.

I suspect , cars that sit for long periods of time, example, in excess of 3 months or more....this gives enough time for things to start to dry up...like the tensioners, and the belts.

Just start your car every few weeks and this will solve many issues.

 

I know why there is so much anxiety here with this issue:

People think: "the only thing between me and a blown motor and a ton of $$$$ is a rubber band running at 7,000 RPM's back there!"

But, it's a really strong rubber band that lasts and lasts for years.

I do agree that the tensioner bearings fail more often to cause a problem--- usually from a lack of use or water from excessive cleaning.

How often did I change mine? Every 3 years just to be safe. YMMV.

 

Must have happened in the history of my car at one point. 2 slightly bent valves needed changing when I rebuilt it 2 years ago.

 

I've extended my luck up to 9 years. Belts looked nice but a little harder than new. The tensionners were probably more than 20 years old at that time and one was making noise. I don't do this anymore. Belts are cheap and easy to replace and the tensionners too.