Why not chains instead of belts?

Nice question. I have a Smart and it uses a chain. Smart service center says it never needs replacing ever. Bold statement and made me think also, why dont all cars use chains?

 

Que all the ferrari brained washed zombies who will say its becourse belts are quiter than chains Oh please Have ya heard a ferrari engine with the cover up

 

It is not Ferrari engine specific but here is an article that will give you some insight...


While a timing chain is nothing more than a traditional internal engine component, a modern belt drive is an invaluable tuning tool that no racer or street horsepower fanatic should be without. Whether you are dyno testing or dialing in your car at the track, you need to be able to quickly adjust the camshaft timing. Camshaft timing is one of the most important tuning aids you can have. By advancing or retarding cam timing, you can compensate for track surface conditions, atmospheric conditions and simply fine-tune every ounce of performance out of your existing combination. The effect of changing cam timing is so significant that many high-end performance cars come from the factory with sophisticated and expensive variable cam-timing devices. For sportsman and bracket racers, it's even more important. If your car isn't hooking up, you can jack it up and make a chassis adjustment that may take 15 minutes or more. Or, with a properly designed belt drive, loosen four bolts and retard the cam timing in the staging lanes in about five minutes—a bracket racer's dream.

Cam timing adjustments can be an important developmental tool on the dyno as well. Not only can you find the "sweet spot" in the power curve, you can move it around to best suit your total engine combination. By experimenting with cam timing and valve lash, a knowledgeable engine builder can determine if he has the best cam for a given application. If not, he may need to run several cams through the engine to find the right one. With a conventional timing-chain setup cam changes are time-consuming, labor-intensive tasks, and with the cost of dyno time these days, you can't afford not to take advantage of all available shortcuts.

A belt drive can make cam timing changes and camshaft swaps less painful. Cam timing changes can be made without removing the water pump and front timing cover. Camshaft swaps are almost as easy as the camshaft will come out through the front cover without removing the timing cover and oil pan, as is standard procedure with a timing chain. This cuts the time for camshaft changes by at least 60%.

There are many more advantages to a belt-drive system than ease of use. A belt drive can increase power over a timing chain through less frictional loss, more precise timing, smoother valvetrain motion and eliminating windage caused by the timing chain and gears running in oil. A belt drive also isolates the crankshaft's torsional vibrations from the camshaft better than a chain (and certainly better than gear drives, which can amplify crank harmonics). Think of it as a second harmonic damper for the rotating assembly. And with all that engine builders are doing to stabilize cylinder-to-cylinder camshaft timing, such as larger-diameter cams, doesn't it make sense to do what you can to precisely phase the camshaft to the crankshaft?

 

Fantastic write up there mate Very relevent to a race/track car. But how does that apply to a road ferrari?? Like my 355 for example were no cam timing device can be fitted while engine is in situ??

 

Aren't Ferrari's built/sold with the thought of their production cars being tuned, operated, and maintained at the same level as a "track car"?

Also, I am thinking its a way to get maximum HP/efficiency out of their engines. Unlike a Viper V10 where 488CID makes gobs of HP by default vs. a smaller, high revving Ferrari V8 or 12 where every aspect effects HP.

I may be off on this one but...Aren't newer Ferrari production cars easier to work on (aka..engines stay in the car) as well vs. older ones where engines have to come out etc., for a belt change.

 

Why belts? I'm sure Ferrari has a reason, but I have suspected for a long time that it is simply nothing more than "we do it because that's the way we do it." Sure, there are some advantages to the true race car. But my Corvette Z06 has timing chains, and the engine can put out plenty of HP. And with a few simple mods, a cam, some new springs and rockers, long tube header exhaust and a dyno tune, I can have that puppy putting out enough HP to run just about any F-car off the road except the highest end supercars. And it's a V-8 with a timing chain.

Just remember, Ferrari is an "exotic". Exotics have their quirks and special attributes. One of those for Ferrari is timing belts. It also represents a full employment opportunity for Ferrari mechanics and a constant chain of parts supplies for Ferrari corporate. It hasn't stopped Ferrari from being one of the most sought-after cars out there. So, in that sense, why change?

 

More food for thought...

My wifes Toyota Mini-van has a timing belt.

It needs changed every 60K miles. Cost 175.00 parts and labor.

sooo...maybe its not the timing belt in question but how easy it is to change.

Even with the "Ferrari Tax" added it really shouldn't cost that much to do if Ferrari designed it that way.

ah the price to pay for the term "exotic" haha.

Also,

How much does it cost to do a belt on a newer Ferrari such as a the 360 or 430?

 

LOL!! you have all over looked one very important thing though, becourse clearly ferrari have changed there way of thinking by having CHAINS in the F430 and not belts. So bang goes the ferrari belt theory.

 

Chas, lets face it the reason most manufacturers use belts is down to cost and cost alone..............does it really matter if they wont admit it, especialy as it doesnt cost a huge amount more in the UK to change a Ferrari 308/328 cam belt than it does a scooby or VW, that don't have hugely different service times (3 years or 50k miles......before you say it most Fcars will do 3 years well before 50k miles )








And if you really want funny, Maserati Ghibli's have both chains and belts!!!!!

 

and there you have it.

how about all the other new/newer Ferrari's? Are they moving/have moved to chains as well?

 

Of course changing belts is a service thing that can generate added revenue for dealers. I am sure F finally caved in on this with the 430. Now throughout the 3 year warranty period for most 430's all that is required is fluids for the most part. That $1,500 belt service gotcha is now gone.

 

Interesting, how does that set up work then?
MB: From a personal point of veiw i have always thought the belt thing was a ferrari tax thing. They would give out there made up theorys and owners would agree becourse "ferrari says so"

 

Enzo has, in fact there was one only last week in the UK were the chain tensoner had broken. Now if that had happend to a belt driven car it would have been very expensive to the whole engine. But instead it was just replaced in a day, and with the engine in (que all the moaners)
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Ferrari first started using belts to drive the camshafts with the Berlinetta Boxer engine. The reasons given were noise reduction and a simplification of the engine casting process (cost).

 

Belts for inlet valves and chains for exhaust, although if you take the radiator out it's a fairly simple job to replace both

 

A timing belt will not stretch. A chain will wear in all the pins and valve timing will change with wear. So the Timing belt does a better job of controlling an important performance parameter (valve timing) than a chain. It does a better job up until the moment it snaps in two..........

 

MMMMMOoooooooooooaaaaaaaaannnnnnnnnnn!!!!!!

 

Here is something new I considered a great advantage of belts over chains, yes Ferrari first used belts on the Berlinetta Boxer flat 12, this was Ferraris first engine expected to last well over 100,000 miles before a rebuild vs the earlier chain driven V12s and Dino V6s which don't have the same longevity, the reason belts transfer less vibration to the cams and crank shaft vs chains making the motors last longer this applies especially under high rpm, in addition to the other benefits of belts of more precise timing, lighter weight for higher revs etc

So thank belts for added longevity of a new generation of Ferrari engines and rumors have it Ferrari is considering going back to belts again..

 

Porsche uses chains and they are known to last over 200K miles. Yes belts are smoother running and quiter, but it was not for longevity. Any way you have an expensive car you should be able to afford the maintenance. As far as cam tuning today's modern technology has done that with electronics and chains ie Variocam or Vanos system.

 

And thank the old Ford GT40s use of the timing chain for the longivity of the new generation of new Ford GTs And thank the old Porsches timing chain for the new generation of more powerfull chain fed newer Porshes

 

Porsche and Ford motors don't rev to 8500 rpm like a Ferrari motor either, 911 motors go to 6700 rpm and Fords a little over 6000rpm as well.

 

Ok ya right, so tell me what do the F430s and the Enzo rev to... You know the chain fed ones

 

Yeah 8500+ rpm but we are talking technology at the time over 30 years ago when Ferrari began using belts, I think it was Dave Helms here that mentioned Ferrari may go back to belts from vibration issues again at high rpm.

I doubt an Enzo motor is going to last 60,000 miles anyway similar to a F50 motor.