The cambelt is at the front of the engine, in the "middle" of the car, which means in order to get access to it the engine has to be removed. Dropping the engine (it is actually removed by raising the car away from it) requires disconnecting of various systems including electrical, air-con, and fuel lines, and the whole job is listed by Ferrari at around 22 hours.

The actual time required to replace the cambelt is much less than the time to remove the engine, and comparatively speaking the belt itself is very cheap.

Are there any other ways of changing it?

Well, yes, there are. Instead of removing the engine it is possible to do the job by removing the fuel tank instead. Once this has been done the necessary clearance becomes available inside the engine bay to change the cambelt. However, this procedure is controversial in Ferrari circles because once a certain point of the operation is reached there is apparently insufficient clearance to complete the job. What is actually done is not fully explained by those that do it but I understand it involves undoing a few more bolts and moving the engine slightly to provide the necessary clearance. There are many people who think this method is a bad way of doing the job but to date no subsequent problems have ever been directly attributed to carrying out a cambelt change this way.

For every one owner that swears by doing it engine out, there will be another that swears by doing it in situ. Because removal of the fuel tank is a much quicker job, in situ cambelt services are signficantly cheaper - usually about half the cost. However, there are some advantages to removing the engine. It is easier for the mechanic to work on and to perform other checks, plus if you want your cam covers reconditioning (these are the parts that are painted red) then it needs to be removed anyway.

How often should it be changed?

In Europe, Ferrari stated that the cambelt should be replaced every 50,000 km or 3 years, whichever comes first. However, in the USA they stated 5 years, and this has prompted some owners to attempt to save money by replacing it less frequently. When cars were still under warranty it was necessary to stick to the schedules in the owners handbook, but now that most cars are out of the main dealer network, owners are free to get cambelts done whenever and however they prefer. For my own car I stick to the owners handbook and do it every three years.

If an F355 has been left standing for a long time, it is possible for the belt to deform due to it having being left in the same position. Cambelts do not tend to actually fail as such, but if a belt has deformed a little then when the engine turns over it may jump off which will result in the damage already discussed.

It is probably true that a cambelt will last much longer than Ferrari servicing schedules suggest, but with an engine rebuild probably costing around £15,000 it just isn't worth the risk.

 

 

Karl runs Verdi Ferrari (www.verdiferrari.biz), and is a very knowledgeable chap regarding Ferraris. Karl does all of his cambelt servicing in-situ unless instructed otherwise by the owner of the vehicle. The die-hards in the Ferrari community often cite reasons why the cambelt must be replaced by removing the engine, and one commonly stated reason is that you cannot set the timing up properly using DTI guages when the engine is in-situ.  Initially this claim seemed reasonable but Karl was able to debunk it entirely by explaining why you don't need to use DTI guages in the first place. What follows is a recount of his explanation to me. I am a much wiser man for it !

 

When Ferrari build an engine, they do two key things. Firstly, they manufacture the engine camshafts etc to very precise tolerances. Secondly, they set the timing up using proper measuring equipment such as DTI guages etc etc. It is a very involved process, but the key point is that once it is properly timed the engineer at the factory scribes very precise marks in four separate places. The most important ones are behind the endplate and under the cam covers on the camshaft itself. Claims about factory marks not being accurate is myth and nothing more. The marks are placed by people who just build engines, and don't do anything else, so the thought that they might scribe marks that are way off is plain ridiculous.

In addition to the scribed marks, there are also some hand written marks on the pulleys which are for guidance only. Given the spacing of the teeth on the cambelt, even these marks are accurate enough to show if the belt is one or more teeth out, assuming the cam timing hasn't been altered by someone.

 

Assuming a car is running well, and assuming the factory marks on the cams under the cam covers or behind the endplates line up, then it is a simple matter to replace the cambelt - even if the belt has stretched. The new belt just brings it back in line. If an engine is running poorly and yet the guide marks line up, this is a sign that someone has been altering the cam timing away from the factory marks, and this will be evident on the cam markings.

The only reasons the timing can be out is if either the factory guide marks simply don't line up, meaning that someone put the belt on wrong, or secondly if someone has messed around with the timing thinking that they can do a better job than the factory. This would be evident by looking at the factory timing marks on the cams to see if they line up.

Conclusion? You don't need to remove the engine to get a proper timing result on changing the cambelt. There are accurately scribed marks on the engine to go by.  A decent mechanic can tell if the timing on an engine is out just by listening to it.