CAMBELT REPLACEMENT EXPOSED

Phil - I generally do my own work, and it is as much therapeutic as functional. However, the average owner does not, and it is wise when removing a 12 cylinder to do all of the ancillary service/restoration at the same time. Thus, one could probably get a belt change for $5,000, but with the added investment in alternator rebuild, water pump rebuild, points, plugs, bearings, etc., etc., you are looking at $10,000.

Please understand that I am as guilty as most with respect to doing the unnecessary, I simply don't rationalize by attributing the investment to Ferrari's service recommendation. It is pride of ownership, much like when sanding a boat every year. Doesn't make it sail faster. Isn't any safer. Just feels better.

Jim S.

 

In Jan 2005 I bought a 1981 308 GTSi. Books showed that the 30,000 service
had been performed in 1989 at 30000 miles by a Ferrari Dealership.
The 308 showed 39500 miles on the speedometer. I insisted the belts be changed. Turns out that the belt behind A.C. WAS NOT changed by the
Ferrari Dealership. The other belt had been changed. The old belt and it's
bearing were next to failure. Got by with 2 belts and 1 bearing.
So I had a 24 year old belt with 39500 miles on it.
Personally I am going with 5 years ( I put on about a 1000 to 1500 miles a year) between belt changes.

Stephen

 

Sorry that idea is crazy and defeats the purpose of the rubber timing belt in the first place, ie. that they are low in inertia and thus allow the engine to accelerate quicker and quieter than chains.

If you really want to make belt failure a non-issue it really is a heck of a lot easier than your suggestion ... simply have the pistons modified to make the engine into what is called a non-interference engine, ie. the pistons and valves can never hit. The negative ... a lower compression ratio.

Remember to think of the obvious before looking for laterial ideas .
Pete
ps: Some owners of Alfa Romeo v6 engines have made them non-interference without huge losses ... but I have no numbers, etc.

 

How many horsepower would a redundant timing belt sap from your engine?!

 

Good question but you have to read the history and understand WHY the rubber timing belt was invented ... by Glas (I think) and then used by FIAT on the 124.

Thus your suggestion is to incorporate 2 timing belts instead of 1 (if I have fully understood your suggestion), thus you now have:
- 2 belts to accelerate, plus all the pulleys, etc.
- Engine length has been compromised and is now longer than it has to be.
- Manufacturing costs have gone up as now we are making 2 of everything.

Thus your suggestion has NO gains, other than the possibility (and it is only a possibility) that if one belt fails the other will continue the job. What you have forgotten is that when a belt fails where is it supposed to go? ... it is stuck inside a belt cover and will thus more than likely get caught by a pulley and do expensive damage to atleast the belt covers ... if not worse and stop a camshaft from turning breaking the other belt!!!

Thus we have:
- Your suggestion.
- Machining the pistons so valves can never hit the pistons ... many Japanese engines do this (by design) and thus belt breakage is no big deal at all ... but not all.
- Simply design the engine to use a timing chain or gears.

Heck just choose the chain, and if your idea was supposed to be a retrofit idea for say existing 308 engines ... hmmm, you could probably do 10 belt changes (including engine removal) before you would get close to the cost and complexity of putting a belt on the flywheel end ... lets see, maybe new crank, new block casting, new camshafts, etc. ... $$$$$$$

I admire laterial thinking , but part of this process 'has to be' a re-evaluation of the suggestion once the excitement has died done.

[EDIT:] Okay I have just triple read your suggestion and the idea of having 2 belts running where the existing belt runs does have merit. The belts would have to be very narrow but acting together they could do the job. Thus your idea is that if one breaks you have a limited amount of time to shut the engine down and get it repaired.

My biggest concern with this idea is what happens to the damaged/broken belt. I broke a fan belt on a Alfa Sud engine (pulley broke!) and the fan belt took out a cam belt ... . If you can solve this then there is an idea worth thinking about ... but in the real world these belt failures (when correctly maintained) are very, very rare.[/EDIT]


The other point that has to be made is this thread and the constant discussions about belt life, etc. is plain embarrassing. Ferrari make a car and they decide that these things (and other parts) should be replaced at certain intervals ... and yet people keep on deciding that they are cleverer than Ferrari and thus go out of their way to prove Ferrari do not know what they are talking about and heck these belts are good for say 100 years ... NOT.

Also as a person that grew up with a family car repair garage ... these belts are easy to replace and whoopy ****. They do not give trouble, just replace them at correct intervals OR when you buy a car with them (to be sure).

Yeah the motor has to come out ... well it does on a Ford Cortina Mk4-5 too. Just pull it out, it is just a car. Now ofcourse it is going to cost lots of bucks if you get a Ferrari dealership to do it ... but so would anything on a Ferrari.

Thus again it comes back to the: If you want to own a Ferrari get ready for large servicing costs.

I have a step son who is getting ready to buy his first car ... all he is thinking about is the purchase price. I (and others) have tried to remind him that there are registration costs, petrol and servicing, etc. ... but just like many Ferrari owners he hasn't got the full picture yet. It will happen and I will be there to help him, where I can ... but you guys buying Ferraris (I don't own one, nor could I afford to have someone service it) should be old and mature enough to have thought this through .

These discussions simply give the false impression that Ferraris are unreliable.
Pete
ps: The only good that I have ever seen that comes from these belt discussions are:
- Somebody who has had one fail posts frighten pictures and the tight @rse Ferrari owners get a wake up call ... and do their maintenance (for once). Heck might even change the oil for the first time .
- Somebody has made a conversion to update the belt to the moderner round tooth design ... a great idea as it is a much stronger belt design and what all (I believe) modern engines use (that use the rubber belt).

 

There is another way rather than chains or belts, and that is just make everything direct geared. That's the way the F1 engine is set up.

 

Actually, the issue is that even Ferrari isn't consistant on the intervals. I have heard from UK chatters that their manuals show 2 years/30,000 miles, while mine clearly reads 52,500 miles without a time limit. Various factory materials since the production of the car show different time/mileage limits. Furthermore, no adjustment for changes in belt construction have been included.

It's not a matter of being "more clever" than the original engineers, it's a matter of trying to get a straight answer from someone, while recognizing that the dealers and repair centers have a profit motive to protect, and that scare tactics and misinformation help improve their bottom line.

 

I am not sure what some west coastguys may have to pay for overhead, but my garage liability costs over $4500 a year, then the shop and equipment costs, add a liveable wage and you are lucky to compete against a "parts fitter" from local domestic shops in this area of US who gets benefits and $50K.
My 512BB services are FULL service, clean and repaint etc, all new hardware, full detail, and runs around $7000, a TR is less.

As for a liveable wage over here, factor my health costs last 3 years with insurance premium included were in excess of $20K average!

Brian

 

When I had the major service done on my BB512i at FoA, I negotiated with them for $3k labor + parts. It ended up costing me around $6k and that included everything...they even re-painted the engine for me and removed various other parts so I could have them re-plated and/or refinished while the car was in the shop. And, with FoA as with most other Ferrari dealers I got a 12 month warranty on th eparts/labor to boot.

 

Exactly. If you call Ferrari UK & ask them about belt intervals on 308s & 328s they will tell you two years or 25K miles. Try & have a discussion about it ( & why its 5 years in the USA) & they'll kind of give you a hint that they know 2 years is a bit daft BUT they'll never waver from the official line.

About 3 months ago I even sent a message to Ferrari through the Owner's website asking why there was a difference between UK & US specs (given the part numbers are all the same) - no reply.

All that said after my own experience I think the things to watch more closely are the tensioner bearings. Mine had to come out & be replaced 2 years & about 3K miles after the previous belt change - at which they would have been checked & found to be fine. If I'd tried to go even another year I think its odds on one of them would have failed catastrophically.

I.

I.

 

Right. If you make two very special rubber belts that overlap each other with the top belt's teeth filling in the gaps where you have holes instead of teeth in the bottom belt, then you would have a redundant timing belt system. It would be tooth-hole,tooth,hole on the bottom special belt...versus the OEM tooth, tooth, tooth, tooth. The top "special" belt would have rubber,tooth,rubber,tooth. It alone would be stronger than the bottom belt and at least as strong as the OEM belt.

Fit together, those two special belts would function as a single OEM belt (tooth, tooth, tooth, tooth), except that if one of the two belts failed, you would not have immediate catastrophic engine damage.

The broken belt would also clang around a good bit, giving the driver ample notice to pull over and shut down the engine prior to there being any real damage done.

You'd probably have a reliable 30 seconds after the first "POP!" and clang, clang sounds to stop the engine before the broken belt gummed up the works or the redundant belt also failed.

This might give many an F-car driver peace of mind, knowing that belt failures were no longer automatically catastrophic with the new dual inter-locking belt setup.

I mean, when you are replacing belts anyway during a Major Service, how many F-car owners would pay an extra $100 to know that *IF* they had a future belt failure, that it wouldn't automatically destroy a $20,000 engine?!

If I'm already in for $4,000 to $6,000 for my Major Service, that extra $100 for an inter-locking, redundant timing belt would start to look like cheap insurance and easy peace of mind.

 

Hear, hear!

What BETTER place to ask technical questions?! Here is where we find out WHY and HOW (sometimes even WHEN and WHERE).

No reason to be embarassed about it. If Ferrari Factory Workshop manuals answered every possible F-car question, then perhaps such forums wouldn't be required, but a lot of F-car knowledge seems to be stored in a few minds rather than in pri9nt or on the Net (so far).

The more information that we get on-line, the better for all F-car owners. There's simply no downside to having real-world answers on-line.

 

Hi..i have a 348 thats on 5 years since cambelt (Not my choice as just bought it)...just checked it and looks mint..BUT it is goin in next week for a new belt.


You have to remember..one cambelt...many valves and 8000rpm odd...imagine the spring ratings....that belt is under proper stress.Remember fibres in the cambelt decay thru age also and with any leaks,moisture it will shorten the life.....

For the 348 its now gone to 3 years from 2 years as we use a new different spec belt...

 

Quick Poll:
How many think this 2nd belt, with half as many teeth (perhaps not as wide, either?), would last 30 seconds before being thrown by the remains of the first belt? I give it... about 1 engine revolution for the broken part of the first belt to get to a pulley. I'm all for thinking out of the box, but don't think this would work...

Face it, these are not cars one buys because they're well engineered. It's a weakness of these cars, just like every other car has some Achilles' heel. Some people have to add extra things to their cars to make them work right, some people have to get odd parts rebuilt that can't be improved upon, we have to change belts frequently. If you want to quit having to do so, it sounds like they're developing an alternative belt drive for the 4 liter project, get one of those and provide feedback as to how well it holds up.

 

How is 3 years frequent??????

LOL @ poor engineering!!!!!..Read my last post...Ferraris are RACE developed that cambelt has a hard time...its clear it will last much longer if you wanted to leave it but Ferrari are just thinkin of US and they know a damn site more!!!

 

In an overlapping two-belt system, with one of the two redundant, overlapping belts finally breaking, you'd have about 30 seconds, reliably, before one broken belt/parts would get hung in the turns and pulleys so thoroughly as to gum up the works.

Ferrari engineering is fine, in some cases, exceptional. That being said, rubber belts can be improved upon. You know full well that direct drive is an improvement over rubber belts. So too are chains an improvement.

I simply pointed out that you could overlap two thin belts to perform the same function as one thick rubber timing belt...and that this dual inter-locking thin-belt arrangement would give you some small amount of redundancy should one of the two belts fail.

Some F-car owners might prefer to use a two-belt redundant timing belt instead of the single OEM rubber belt...if given the option during a Major Service.

This is the sort of thing that the Aftermarket *should* be doing...i.e. giving F-car owners various options.

 

Umm, where do the bottom belt's fibres run if there are hole gaps between the teeth?

 

Around the gaps.

 

Why does it last for 30 seconds? Why not 3 or 90?
At a moderate 3000 RPM, you're turning 50 revolutions/second. That means that broken end of the belt will hit a pulley 50 times/second. I'll put my gut feel on how this would work up against yours. Or do you have some experience with these designs that shows they can hold up for over 1000 revolutions before the belts become intertwined? It's neat to come up with new ideas, this one just won't fly. I wish I could come offer a suggestion to salvage the idea, but it hasn't hit me yet.
And as for Ferrari engineering... I _AM_ an automotive engineer and I haven't seen a whole lot of it to be impressed by on my 308. Perhaps your ride is different...

 

Fair enough but we have done this to before ... I believe (do a search)

I'm not a professional, I just do maintenance as the car maker states ... and thus don't have problems. BUT it is interesting and confusing that Ferrari are not consistent in this area

Fair enough ... I leave you all to it
Pete

 

A broken belt on a still turning engine is going to hit lots of things, pulleys, cam covers, engine block, other belts, etc. This is bad for most of what it slaps, of course, but it still takes a few moments before that high speed belt slapping will lodge itself firmly enough *somewhere* so as to gum up the works. So while some light damage is being done from the slaps (as early as the first rpm apres-break), it is the broken belt getting lodged (at least in the sort of redundant two-belt system under discussion) that will be the engine breaker. The slapping alone won't do it, and it takes time for a broken belt to get lodged or knotted accidentally (I've broken a belt on a Corvette and the belt still hadn't gotten lodged by the time I drove the car to the Dealership for a new one).

The sharp belt-breaking original "POP!" will get the Driver's attention, as will the slap, slap, slapping noise...so it's to be expected that the car will quickly be dropped to idle...and soon stopped (hopefully by the Driver prior to actual valve/piston damage).

Acceleration will not be an option once one such a dual belt breaks. In fact, it would be unusual for the Driver to even keep the engine at the same speed. Almost certainly the reflexive action will be to come off the gas entirely, as immediately as human reflexes permit.

 

Never heard anything when I've broken belts ... and yes I have on race (non Ferrari) engines broken belts when camshafts seized.

I do not believe this is a design weakness, well atleast as big as some make it out to be. The problem is:

- Many Ferraris are infrequently driven ... this is very bad for rubber components as they have memory and go hard when not warmed, etc.
- It is now an old design, ie. new rubber belt systems do not use the small square teeth ... and thus needs more maintenance than we find acceptable ... thus the modern belt solution that somebody on this site has developed makes sense.
- Many owners can only just afford the purchase price and thus do NOT do proper maintenance.

I fully believe that if the car is maintained properly and USED that this is a non-issue. Ask Jim Napolis ... he put 100,000 miles on his Testarossa!

Jim did actually have an engine problem with his 308 (I believe) but it was replaced under warranty.
Pete
ps: Oops I said I'd leave you guys alone ... . Bye and best of luck with your rubber belts.