Why did Ferrari use belts instead of chains?

Maintenance should always be a car purchase concern. Right along with what is included in a competent job for the price quoted. Gaining knowledge is not a weakness.
While there seems to be lots of banter here about the merit of belts vs chains, one question was not answered. What did the Enzo motor have, was it gears? If gears were good enough for the Enzo then why was the flavour of the moment the 'Ferrari 599' saddled with mere chains instead of gears? Chains would seem to have a shorter life cycle than gears, or not?
CH

 

I like the belts on the 355... though it would have been great if they located them on the back of the motor.

 

AFAIK, all reciprocating aircraft engines have all gear driven internals, and in the case of those with speed reduction drives to the prop, they are gears as well. Between Lycoming, Continental and Franklin, I never seen or heard of a chain anywhere inside an aircraft engine even in prewar engines. But as stated, they not only operate at a low to medium speed, they also have no need to accelerate. They just drone along for hours with no real changes in rpm. However there are many experimental aircraft running Subaru, Honda, and Suzuki engines today, not only with cog timing belts, but cog belt reduction drives as well. In fact the Diamond aircraft had an opposed Rotax engine that used timing belts IIRC, but I think they dropped it and now only offer the Continental.

The single greatest issue holding back major advances in aircraft and aircraft engine design have been lawsuits. And as long as the aircraft and engine manufactures keep getting sued over machines they built 50 and 60 years ago, nothing will change a great deal. Lawyers look at changes as admissions something was wrong with the original design, as well as pounce on new designs as not being fully developed. Its a no win situation.

 

Agree on the airplanes gears only - could not recall a single chain either except of course for auto engine conversions. Maybe the old Ranger straight six or V12? Probably not - for fear of it snapping a link.

And the process of getting an FAA approval on a new design is just about like waking the dead; probably for the same reason that Artvonne mentions about lawsuits and the CYA factor of a government agency.

On the gears only on the Enzo - is that true? I thought the new V12 cars had pretty much the same engine as an Enzo, just packaged differently. Anyway, the bad rap I always heard on gears was noise and premature wear due to harmonic vibrations - stuff that presumably gets damped out with the shock absorbing nature of a belt or chain.

 

Unless there is a goofup somewhere, this is a page off of Eurospares showing the timing chain for the Enzo.
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The debate will rage on for a long time to come. One has to only look back to the early 80's with Porsche and their cam chains to see they are not without fault. Porsche went through 4 or 5 variations of their chain tensioners? Seems each month there was some new design that was declared bomb proof. The F50 and their Morse type chains prooved to be suited to the design. Due to the nature of its design the Morse type chain creates a good deal of wear to the components it contacts. Chyrsler used it in a perfect application, the slant 6 which proved itself reliable past 250K miles but used a huge plastic gear and a soft cast iron gear that would take the pinching action and not self destruct running at what, 3k RPM? Run the same design on case hardened gears and trouble awaits, we have seen it.
Roller chains have been great on the early 250 / 330 / 365 engines but streatch is an issue on those. If I remember correctly the long, double row cam chain replacement interval (suggested) was in the 26K mile range.
The advantage the Enzo and 430 have with their chains is the short length and a large broad tensioner shoe. When that plastic shoe wears out it will require replacement. Heck, its still plastic against a metal chain running along at a high speed. When the chain stretches and the link center to center length no longer matches the gear center to center measurement a high rate of wear will occure and all of the components will require replacement. How long will that be? Time will tell, no one knows yet but it will require major work to maintain when it comes time. Rest assured, an engine running at this RPM will require maintaince on the chain system. When it does it will be far more expensive than if it had belts in place. We are all hoping that the maintaince costs will average less than with belts, I for one am not too sure that will prove to be the case.

What happens when a belt stretches? The tooth centerline no longer matches the gear cog centerline and the belt tooth width wears narrower to match. Take it off and replace it. No damage done to the gears (exception, the goofy plastic gears used on the 2V), no metal debris (gear material worn but a stretched chain) flowing through the engine, no tearing the whole front of the engine off to replace sealed components. The belt drive engines and drivetrain are designed for quick and easy removal / access to accomidate the required replacement, not so with the chain systems.

One of the major advantages of the belt system is it transfers very little harmonic vibration from the bottom end of the engine to the valve train. Harmonics in the valve train is the major limiting factor to Redline limits and overall reliabilty. One only has to look at the RPM the F1 cars are running to see the same basic design we all have in the bottom end of the engines in our cars is well if not over designed. It is the valve train that is the weakest link and in my opinion the belts offer a huge advantage in this area over chains.

Everything wears and stretches, chains are no exception. Will they outlast the belts? Yes. Will the average maintaince cost with chains proove cheaper than belts? Sure hope so but there are many variables in play here. I am not sold on the idea it will be cheaper in the long run. Surely it will for the first owner given the mileage / year these cars see.

Dave

 

Well, Dave, your response is certainly thorough and well thought-out.

I thought I had "done my homework" when I bought an affordable Ferrari, and it continues to serve me well. (Many thanks to you!) But believe it or not, none of my pre-purchase research said anything about timing belt intervals!

I had the car two weeks when I learned about a suggested timing belt interval of 30,000 miles. I bought my Ferrari with over twice that many, so I called up the previous owner and asked when he'd last changed the timing belts. He said, "Timing belts?" as if he'd never heard of them. In all the time he'd owned the car, and all the miles he'd put on it, he had NEVER changed the belts. (Needless to say, I immediately took the car to Los Gatos and had the belts changed, as well as some other engine work done!)

So, this is the first I've heard of "goofy plastic gears" in my 2v. What do I need to know about them?

 

Agreed that chains/sprockets are not without problems. It seems that the real advantage over belts is the fact that they run "in oil". All the parts are continuously lubricated. Some metal debris over time is inevitable and is certainly a check mark in the "minus" category.

If the sealed tensioner bearings could stand up and if the water pump was separately driven the belt service life would not be much of an issue. Harmonic dampening in a belt system is a big "plus" as is the relative ease of maintenance (once you get the damned engine out!).

 

Well said "Mr Newman".

 

LOL, if the shoe fits.....I thought I was being nice calling you a dink. Out of the 2 or 3 long term members here that are dinks you are number 1 in my books. Your instinct seems to be to attack someone rather than say nothing at all. Americanpie is a new member with questions, I doubt you "knew it all" before you bought your first 308 (you know it all now though, lol) and did some dink jump all over you over a valid question? Nice going Paul, drive the new members away with your "better than thou" attitude. "I know everything about 308s and ferrari engine technology because I change oil on airplanes and clean the trash out from under the passenger seats", lol. Me arrogant? Sometimes but we are all guilty of that at times even you. As for PM's from other members, I got an email yesterday regarding your comments in the boxer section sharing their opinions of you, it was quite funny and accurate.

 

you're welcome, feel free to ask anything because thats what this site is all about. You'll find lots of useful info here. When I bought my 308 I didnt know about this site until just after. I wish I had known ahead of time though because I went into ownership blind and learned some hard lessons.

As for belts vs chains, its said chains cost more HP due to the weight and drag. I dont care if I have chains or belts, they both have their problems and I dont think ANYONE realy knows but ferrari, as to the reasons for running belts or chains.

 

mclaren is a bmw v12. pagani is a mercedes v12. bently is a VW vr6 based engine. yes. they all use chains.


regarding interference engines...most hondas are. most nissans and toyotas are. most mitsubishis are. they all use belts. ford engines using belts (including the nissan V6 in the villager) are non-interference. the chain engines are interference. the nissan v6 when NOT used in the villager is interference. my mitsubishi has one of the longest timing belts i have seen. hydraulic tensioner much like the 360, 2 pulleys and a water pump. it can be changed in the car. the hyundai sante fe (has a version of the same engine in my mitsubishi) can not have the belt changed with the engine in the car AT ALL. there is no way around it. IIRC labor for the job is around 18 hours.

heres my belt setup.





the only reason im here (i dont own a ferrari) is a very good friend of mine just got a 360 modena so im doing some research since ill be working on it for him.

 

Gears

 

In the four years I have been on Fchat, I have seen more new posters politely, and not so politely shown how to do a search.

That said it was interesting to note the number of threads that came up under a seach typed simply "belts". Among the threads specifically in reference to timing belts, the vast majority clearly regard their life expectancy and replacement. And thats only under "belts". It also comes up in any other discussion where someone talks about anything service related. But some of the threads found under "belts" ask: "Why rubber belts", "should I change my belts", "how old is to old on belts", "just how bad is it when belts go bad", "timing belts issue yet again", "lets set the record straight on belts", "why not chains instead of belts", FYI timing belts again-read this", "35K miles and 11 years on belts", "just changed belts 14 years and 20K miles", "23K on belts", "308 belts DO break", "what happens if you dont change belts"..... There are 146 threads dealing with the subject "belts", and over a third deal directly with "timing belts". This short list is barely into the second of three pages. I found 197 threads when I typed in "timing belts". If I had been stupid enough to come into Fchat as a new poster fours years ago asking questions related to defering maintainance in order to afford the car, more than a few members would have directed me to the search function. As many here know, I have been among those that could usually care less about new threads, but this particular subject is beat around so much its absolutely rediculous. If you had been lurking for any length of time as you say you have, you would clearly have seen this before now.

If I used my local area as a measuring stick, I would surmise that over a quarter of older Ferrari owners worldwide are on Fchat and post semi regularly. I wholeheartedly believe there are fewer than 30% of the original production of 308's left in existence, especially among the oldest cars. Using a 25% factor of Fchat members to worldwide ownership, you come up with virtulally the same small number of cars left, about 20-30% of the total production, or roughly 2000 cars worldwide. The cars are rapidly disappearing, from fires due mainly (but not always) to old fuel lines and poor electrical systems, from accidents, and from broken and unmaintained cars. If some of you really care about these cars, maintaining them reasonably is the ONLY way to preserve them. Its not just the belts that shouldnt be run more than five to seven years before absolute replacement, its everything made of rubber, from the tires to the fuel lines to all the belts. So if I'm a dink for standing up and trying to get people to take care of the damned things and stop trying to be so cheap, then its a label I will wear proudly. Excuse me now, I have to back to work cleaning up the trash under the airplane seats, so I can continue to own a Ferrari.

 

Yes, there have been many belts vx chains threads before - BUT - I have learned two or three important new things already from this thread:

a) - As I had suspected, we seem to agree that most airplanes have gears.

b) - The Enzo had a chain drive.

c) - Some of us have an attitude problem, and other of us are dinks.

All of these things were worth learning, so thanks new poster for bringing up the subject of belts again.

 

Boys....boys ....boys.......

To the OP, here's the deal.

Ferrari built it's most popular line the DOHC V8s and made THOUSANDS of them with stated change intervals originally very long, for my early 308GTBs, then later, other engine designs were found to require a shorter interval..

There is a TECHNICAL BULLETIN that only a FNA mechanic would have (I have several copies of it) that just clearly states:

3 years...........30K miles...............whichever comes first....PERIOD.

Now there you have it, from the Legal Department!!! LOL!

Obviously though, IMO there's huge difference in the modern CAT equipped 360/430s that are driven hard under Warranty, the 348 which only has ONE big belt handling the whole engine, the QVs and Injected 308 2vs that have CATS also, and then finally there's the old NON CAT early cars trundling down the road, running cool under the hood, shifting short of the redline in deference to 30 year old brittle sodium filled valves.

I have one car personally blessed by Mario Andretti before running thru Death Valley that was on 12 year old belts at the time and that was four years ago!

But it's sitting quietly among a herd of Longhorns, if I was gonna actually use it belts AND tensioners bearings would be the first stop.........

 

Sorry mate I'm on Artvonne side. This subject has become so boring that we should ask Rob to create a separate section for lazy people to continue re-ask the same question. And yes in most of those threads the REASON (which is what you were after) is completely explained ... over and over and over and over and over and over and over and over and over and over again

BTW: Threads that have a little argument/debate or are just plain silly in them get the most attention, so if attention is what you are after I suggest you create a "Why are wheels round" thread. That will probably become a FerrariChat legend

Best ... and yes I also am bored at work ... oh and Ferrari used rubber timing belts in the 80's because it was then the superior technology (actually I still think it is the superior method), just like everything else they design into their cars. Yep they believed drum brakes were superior too in the late 50's and early 60's ...
Pete
ps: The most constructive/mature thing we ALL can do with these regurgitated threads is to post a link to ever existing thread that covers this topic already and then request that it is closed.

 

Seriously, if that were done, this site would dry up die. I say if people are bored, go on to the next thread. It is Ferrari..CHAT.


Darrell.

 

Those F1 engines had a maximum duty cycle of something just greater than 2 hours, iirc.

 

Your right Dave, I been thinking the same thing.

While I have never had to go around cleaning trash out from under seats for a living, I know damned well there are others on this forum who do, or who do other types of honest labor. For someone on this forum to look down thier nose at hard working people in this way is so out of line there just arent words to describe the feeling it gives me. Makes me wonder if this is how they look upon people who do service work for them or car mechanics in general. But that kind of attitude is so well established that most everyone looks at Ferrari owners with the same kind of regard because they expect that kind of snobbery. Maybe thats why a Ferrari is the most likey car to get keyed up in a parking lot. Maybe the last guy they seen in a Ferrari told them to go clean up the trash under the seats, or looked down thier nose at them. So being called a dink by people with that kind of attitude is really of no consequence. I just consider the source.

 

Paul is a hard working mechanic on the floor of a car dealership. He owns 2 Ferrari's, the Boxer and the 308 which he is in the process of restoring. He builds race engines for a number of performance shops and businesses. He is a good guy. Although he may seem to come off a bit harsh, he is looking out for the best interest of people who own these cars and love them as much as he does. Sometimes people do need that little bit of a nudge for them to see straight and not cut corners, and they do need to be told straight up and without sugar coating it.

Dave Helms I so wish you would post more. You're knowledge has helped me out many times, and I often search this site looking for you're posts. But I see and understand where you are coming from in regards to the general attitude towards professional mechanics on this site regarding the costs of service work on these cars. Its one of the reasons I don't post much anymore.

Timings belts or chains..they both have there advantages and disadvantages. Anything that moves is going to wear out in time. They will all need maintenance. Is Ferrari soaking the owners of belt driven cars?? Who knows. My opinion is yes. But they do have to keep the doors open and the lights on just like any other business.