Why did Ferrari use belts instead of chains?

Belts are more efficient and reduce the amount of power needed to turn the engine. Ferrari probably used them because they lasted a sufficiently long time. My 328 manual recommends a belt change at about 52,000 miles. Assuming one would use the car as a normal daily driver that is about 10,000 per year and 5-year time line. Now Ferrari NA recommends a 3-year time limit for belts, but there are other threads debating that time recommendation. Remember that the engines built by Ferrari were based off of their racing engine technology and thus used belts. These engines were high rpm, lower displacement engines (8000 rpm limit) while the cars in the US were low RPM higher displacement engines using chains.

There is no doubt more to this story, but this is my understanding in a nut shell.

 

It is only so expensive because "while the engine is out, well heck we might as well detail this and detail that and replace this and replace that ...", thus it is not the belts and pulleys that cost the money but the labour and extra stuff while there that adds up.

Ducati superbikes use belts and belts are superior, but Ferrari have changed back to chains so that owners can continue with the poor (pun intended) maintenance attitude to Ferraris (heck it only sits in the shed and hardly ever gets used ... ). Even normal cars flip from belts to chains and then back to belts and then chains every so many new models so expect Ferrari to return to belts one day again.

Pete

 

When you look at the listed amount of work that is normally done during a full service, you would realise the timing belts are but a small fraction. If I simply changed the belts and did nothing else, it would barely be two hours labor. So I see it as neither difficult OR expensive. The three year belt change shouldnt even cost $500 if you paid to have it done. Less than $100 if you did it yourself.

[/QUOTE] I find this especially strange since chains are generally the preferred cam drive for most high-perf cars, and Ferrari reverted to chains in the mid 90s. Was it just a bad engineering decision? Or do most of you feel the motivating factor was purely profit for their dealers' service departments? [/QUOTE]

As PSk pointed out, belts actually are a performance advantage. Thier light weight gives lower enertia to help engine throttle response and acceleration, much like lightening a flywheel or other internal engine parts. And as PSk pointed out, Ferrari caved to idiotic owners who have persisted in thier lack of maintaining anything, and it was making Ferrari look like thier cars were crap.

If your in the camp trying to find ways to get around maintainance before you even buy a Ferrari, please buy something else. Leave the 308's and other belt driven cars to the real men who know what they need, and arent so cheap or so afraid to take care of them.

 

People talk like Ferrari is the only car manufacturer ever to use timing belts. Lots of manufacturers do. And service intervals I've seen range from as low as 30,000 miles to 90,000 miles. And timing chains are not the be-all and end-all of motors either. Many cars have had problems with timing chain tensioners breaking, especially in some of the newer cars that use plastic tensioners.

Doing a belt service is part of the routine maintenance of these cars. I wish folks would stop acting like it's the end of the world. If you want one of these cars, it comes with the territory; it's part of the fun and the cost of ownership. If you can't live with that, go buy a Toyota (Oh, wait; be careful -- most of their models have timing belts too).

 

[ If your in the camp trying to find ways to get around maintainance before you even buy a Ferrari, please buy something else. Leave the 308's and other belt driven cars to the real men who know what they need, and arent so cheap or so afraid to take care of them.[/QUOTE]
Very well put!
I have snaped a timing chain on a 911 Porsche (lucky it was a "T" with cast iron rocker arms and just broke the arm when the piston hit the valve.
I have had a timing chain slip a tooth on a wore out Toyota pickup
I have had the chains come apart on my Citreon SM at 30,000 miles , on this car the secondary chains are to be manually adjusted every 2,000 miles if you do not they will snap.

If you are not aware of engines that much I do understand how you can come to simple but false concluisons, I have done it also, hope this helps.

 

I have an Infiniti Q45 that had to have new chains and guides put in at about 120K miles. It's great engine except for that. It seems thy used plastic guides and eventually those fail.
Then the chain drags across the top of the oil pump housing.

When I got mine apart to replace everything it had almost cut all the way through the housing. This going to sound a bit crazy, it was still intact but you could see through the metal.
I was that close to a catastrophic failure.

Bob S.

 

I want to point out a couple of errors.

1. Ferrari did not revert to chains in the 90's. The 430 is the first regular production Ferrari since the Dino to use chains (not sure about the Enzo).

2. Dinos and Daytonas had higher rev limits than 308's using chains.

JohnyS: Ferrari put the 52.5K recommendation in the manuals to satisfy US requirements that emissions realted equipment, which includes timing mechanisms, last that long. Ferrari also snuck in the time interval recommendations in the owners manual. They also knew that the belts would likely be changed long before that when the tensioner bearings failed.

FasterisBetter: True enough, but very few motors by other manufacturers have valve-piston collisions when the belt breaks. Chains are better in interference motors for that reason.

I think Ferrari used belts becasue they were a lot cheaper to use, especially on the flat 12's. In the 430 brochure, they claimed they went to chains to keep the motor shorter. I suppose that may be true since they stuffed a much larger motor into an engine bay the same size as the 360.

Dave

 

As a newcomer, I'm afraid you touched on the one topic that has 10x the threads and 10x more posts/thread than any other topic.

The cam belt reliability & design choices topic has been thoroughly beaten to death in just about every thread. Unfortunately, most of us have gotten very frustrated because there's been very little new facts & lots of ill founded opinion in the threads. There's been so much hip shooting by uninformed people that don't like the answers given by the consultants, and differences of opinion, that an awful lot of us (myself included) have at times lost our cool in responding.

I for 1 would love to see some new information with 'facts', but unless someone manages to find a retired Ferrari engine designer get him to tell the real story, I doubt that we'll ever know much more than has already been posted in this thread.

SEARCH IS YOUR FRIEND
Just do an advanced search of Tech Q&A and 328/308/Mondial for titles with 'belt' to read more about cam belts than you ever wanted to know. Last time I ran the search I came up with over 130 threads!!!

BTW, there are some excellent threads that smg2 started on 'new cam belt system design'. These do have a lot of facts & are worth reading. The new design cam system has after-market pulleys that permit using a state of the art cam belt that should be significantly more reliable than the original belts. How much more in this application is hard to quantify, design data from Gates indicates on the order of 60K miles or more.

Good reading & welcome to FerrariChat.

 

Dont apologize, Artvonne was being a dink, you had a valid question. Welcome aboard.

 

This is going to be an unpopular post with enthusiasts...but here it is:

Ferrari-as a manufacturer-is concerned with only 1 thing(as are all OEM manufacturers), and that is the delivery of the cheapest cost of goods and services manufactured product to their distribution network.
Ferrari only offers a warranty because the US government requires it....period...

the cost of manufacture in the factories is much cheaper using belts....

M/B found that going to a 3 valve head design from the M119 4 valve engine familes cut manufacturing costs -with the bonus of reduced emisssions-by a third....forget all of the Madison ave garbage....Ferrari is a corporation with enormous overhead and operating expenses...cut where you can....

It is the hard, cold, truth....there is NO romance involved her, just the bottom line...

 

McLaren F1 uses timing CHAINS. Pagani uses CHAINS. Mercedes SL65 V12 Twin Turbo uses chains. BMW V12, M70 and N73, use chains. Bentley W12 Twin turbo uses chains. The advantages of belts are outweighed by disadvantages when the entire motor has to come out to replace them. Ferrari services would be a lot less if there were no belts and thus no motor removals. E.g., I believe TR resale would be much higher if people didn't know of its now infamous service costs as reported in the magazines when the TR was first unveiled. People were then shocked to read the entire motor had to come out to change rubber belts which needed to be changed every few years. The cost of such a service was equivalent to a new Honda back then. Belts, phewy! Give me a few ounces more and a 100k mile plus chain.

 

ExcelsiorZ,

Not all cars that employ timing belts have to have their engines removed to replace the belts, so please be careful with these generisations. I believe the 348 T-belt can be changed with the engine in. Many later Alfa Romeos use T belts and they are changed with the engine in the car ... so maybe the blame should be aimed at the fact that Ferrari have never designed their cars to be worked on ... hence the millions of special tools required. That is the real fault/problem.

Hardtop,

Using belts or chains does not affect the engines peak rev ability, it is about the engines acceleration speed. A lighter T belt engine with everything else exactly the same should accelerate quicker.

335s,

America is not the only country in the world that requests quality products, so America is NOT the only reason the concept of a waranty was invented ... yes really. Yes the World and America are not equivalent, yes really (Buy a globe [that was not produced in America] to check).

I'm trying to understand why the cost of mainfacture would be cheaper using belts. My first thought was yes you are right, but now I'm not so sure. Both designs need pulleys, both designs need tensioners. One difference is that the chain needs lubrication, but that is usually solved by just having it in the same internal area as the crankcase thus the oil mist will lubricate and also oil as it drains from the heads. In fact the T belt design requires MORE oil seals, thus surely a cost.

When the 308 was created it was the current engine design trend to use T-belts ... that is the main reason AND also because a 308 engine is really pretty much 2 x FIAT 124 engines (which ofcourse use T belts, same designer and around same time) on a common crankcase.


Like I said in my original poast to this thread, trends change and now the chain is back in vogue, heck maybe next year it will be gears or maybe they will swing back to belts, with them on the back of the engine so access is dead easy ... who knows?.

Anyway the costs of replacing the belts is very inacurate as Artvonne and I pointed out. If owners really just had the belts replaced instead of the whole engine bay detailed, etc. it would not be so expensive.
Pete

 

Honda (old reliable) uses belts and an interferrence motor just like Ferrari. They require change of belts every 60K miles. Difference is they can be changed with the engine in the car for around $600.

It's not that Ferrari belts have limited life or need to be changed, it's the cost of service that gets me.

 

I don't know about every Honda motor, but a friend's accord threw a belt without damage.

Dave

 

I know chains vs belts has nothing to do with rev limits, but some people think belts will rev higher. I doubt chains have an appreciable effect on engine response, the real power drain is rotating the cams with all those valve springs pressing against them.

T think the 3008 motor was really 2/3 of a daytona. The bore and stroke are identical.

Dave

 

Ahh the M119 was arguably the best v8 Mercedes has ever produced. The 112 (v6) and 113 were (v8) were crap and as stated done to cut costs. This was a time when there was allot of red numbers on Mercedes sheets. They have since gone back to the 4-valve setup which is like the end of a bad dream for many Mercedes enthusiasts along with Shrempp being outed, not to mention the Chrysler sale Sorry for the thread jack, couldnt resist some MB talk though..

 

I always thought it was because the Pope said that chains are "kinky".

 

The following pics are all F1 and F2 gran prix racing engines. These are all interference engines (break a belt, blow the engine), and all rev far beyond any road car, many to 13,000 rpm and higher. When Ferrari built and ran the flat 12 Formula One engine, it was the first to use a timing belt in a Formula One engine with any success. Notice the Subaru engine. That engine was built in the 90's! Renault ran thier "timing belted" Gordini V6 into the 80's as both an F1 and an F2 engine, in both N/A and turbo, and put quite a few trophys on thier shelf. And in the 1980's, Ferrari gave the world the F-40, a car that is still a supercar and still winning races around the world, complete with (the horror) timing belts. If you really think Ferrari built a $400K racing machine of state of the art space age materials only to go cheap on the valve train, I want what your smoking. The FACT is that the timing belt worked BETTER, and MADE MORE POWER than anything else AT THAT TIME. We have moved forward. Advances in metalurgy, friction loss and manufacturing may now have given the timing chain an edge today, tomorrow we may see belts again, or maybe gears or some other drive mechanism. But the same issues will always apply, namely keeping it running, and repairing things in a timely manner before they self destruct.

In the 1980's the United States EPA enacted legislation that required all passenger car motor vehicles sold in the US to carry a 50K miles or 5 years emissions warrantee. All parts and systems that directly or indirectly controlled emissions had to carry that warrantee. Ferrari were FORCED to extend the service limit on the timing belts and accept some engine losses, and simularly they were FORCED to publish that service schedule in the manuals. But the EPA didnt make the belts or design the engine. Ferrari has since published service bulletins regarding the life expectancy of the belts. The service bulletins "supercede" all prior information. If you want to continue believing the belts will last 50K miles, based on something Ferrari were FORCED to print in the manual by some USA government bureaucracy, you do so at your own ignorance.

And Mr. Newman? I may be a dink to you, as I think every one on Fchat is to you in your myopic mind. But in the four years I have been on Fchat, I can think of few people who have been repeatedly more arrogant and condescending to everyone at large. I have recieved PM's from over a dozen different members over these few years who have specifically addressed your arrogance, so I wouldnt get to opinionated about the lofty status you envision for yourself. In most cases, like this thread, you offer nothing of any value except to belittle someone. So you may want to look in the mirror before you start calling people names like a 4 year old.
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login

 

Also the fact that they got into a patent lawsuit with a claimed private inventor over the 3-valve.

The belt thing, of course, will probably always be with us. I think the 3 to 5 years schedule no matter the miles is way conservative. However, the point could very well be made that these older mid-engine cars may probably need the engine pulled once in a while anyway just to get at some of the hidden components (other than the belts) for routine maintanence. So in that case it is more an "ease of access" issue rather than a "timing belt" thing per se.

I think that each way (bets, chains) probably has some advantages & disadvantages - but I somehow have a kind of cynical view that the new chain-drive cars may very well have some hidden maintenance cost gotchas lurking in them as well. After all, they are Ferrari's being sold by FNA.

 

what does a modern piston-engined aircraft use?

 

For opposed-piston designs, I think either a metal chain or just gears. They are pushrod engines with a central cam like a V-dub.

 

Funny thing about piston aircraft engines, a lot of pilots do not like change they trust and know certain desigens and do not want to risk something new, so some of the most common privete plane engines or 50 plus? year old designs and tecno. for instance carburators and magneto's or still sold new and used alot in light air craft, maybe James could help me out on the design age of the Lycomy's and Cont. engines. Reliability and weight or way more important than horse power and flexibilty of the power band and emmision laws. so aircraft is like looking at NASCAR for ideas. Neat but very diffrent needs than most automotive regs.

 

I am pretty sure they go back to just about the mid-late 1930s for the opposed design. The little LT5 WWII observation plane (like Hank Fonda was using to find the Germans in Battle of the Bulge) was for all real purposes pretty much a basic design clone of my later Citabria made in 1969 - engine and all.

They only turn in the mid to high 2000 RPM range, and they always put out very low HP per CID. Mine, for example, was a Lyc 0-230 but it only made 115 HP. The 230 means cubic inches, the O means Opposed Piston. IIRC, Beech Bonanza engines with 260 hp were Continental O-540 or about that. The little carbureted ones also do not have "driveability" things like auto-choke, warmup control (other than the pilot working the mixture around & pumping a manual primer), or an automatic spark advance. They do have dual magnetos and full dual ignition that can run without any battery power...and used about 50wt straight grade oil that looks like grease.
I was thinking they do not even have a timing chain, just a pair of big gears, but it has been a long time since I have seen one apart.

but what Fritz is saying is really so - these things are beasts of the past. It would probably be prohibitively expensive to try too much major engineering rework on them now; this is reserved for the more practical turbine and jet units.

Except maybe for Porsche, who tried mightily to adapt their OHC flat-six into a private plane engine (and pretty much failed). I think it may be still used in a few small airships. It was generally considered "dangerously advanced" and risky high-RPM technology by the conservative private aircraft industry in it's day.

OK - enough thread hijack. I will step back into bounds with this: I don't think it is really accurate to just chime in and say BOOO to BELTS & HOORAY for CHAINS if we were not in the engineering loop that built these engines in the first place. These designers, like the airplance people, had reasons for doing what they did at the time.

I am willing to drive mine (Testarossa) within the limitations and follow a reasonable maintenance schedule.