Always wondered this.... what are the advantages of using rubber timing belts on an engine that need changing rather than a metal timing chain that doesn't? Or is it just a weight issue.. And...does Ferrari always use rubber belts or are there any engines with chains? Howard
Rubber timing belts allowed engineers to design motors to have less noise , excellent reliability with higher rev limits with less expense.......however that was then....now with the advent of the 430 , 458 (and other manufacturers as well) timing chains have advanced to the point where they are now both durable and quiet for high rev'g motors. Of course the down side of rubber timing belts is the regular servicing costs every 3-5 years for the owner.
Good question... and it's been asked a few times over the years. Search results bring up several, including this one: http://www.ferrarichat.com/forum/showthread.php?t=317391&highlight=timing+chains However, the keywords are timing and chains since there are hundreds of timing belt threads already.
Bottom line, the chains need to be lubed constantly somehow someway, retrofitting won't work due to this reason, and I'm pretty sure this isn't the only reason why.
And on most cars, timing belts are good for at least 60k, if not 90k miles. The car is long gone from dealer service. But doing a timing belt on a car where the timing is cover is right in front is not a big deal. If we had to change timing belts every 90k miles, even at $3-5k, would anyone really care that much? That is like (at least) 15 years of driving on most Ferrari's!!! Kind of like doing it every 30k or every 5 years for $1-$1.5k, $200-$300 year. NBD. Regards, Jerry
Other than timing belt, what other parts are required to be replaced in every 3-5yrs? Assuming the owner will put approximately 5k miles per year.
It's been said a million times that changing the belts is not the (only) reason to remove and service the engine every 3-5 years. It's not a Honda Civic.
That's where I was getting into. 360/460 owners claimed their ownership cost is much lower than 348/355 due to the fact it's very rare to remove the engine from 360/460 chassis to have it serviced. This got me think, timing belt is one thing, but I get the impression 360/460 has a better built quality tensioners, bearings, waterpump components compared to 348/355? What if those other components other than timing belt don't need to be replaced, to tell you the truth, it's not the best engineering if the engine components need to be replaced in every 3-5yrs. Especially how many miles 348/355 owners put on them per yearly basis. As you 348/355 owners have demonstrated already, the built quality of 348/355 aren't there, another reason why the aftermarket parts are being recommended rather than sticking with OEM Ferrari sourced parts, correct? Are aftermarket parts still need to be replaced in every 3-5yrs while the engine is out? I know 348/355 owners tend to have a mentality to replace *all* while the engine is out, which I understand and we all know this is the part of the reason why bringing up the maintenance cost. I'm trying to get to the root cause of these parts need attention every so often. Are these timing belts still being manufactured using the old technology? I'm not in R&D nor manufacturing business, but don't we have better materials and manufacturing process compared to 1990s? which can make these belts to last longer than darn 3-5yrs? Maybe the market isn't there, why change and invest as the old manufacturing process and the product still gets sold w/o problems.
Don't get me wrong, 348/355 tops among Ferrari models, but I've been considering 360 due to the ownership cost, it's only little more than 355. But I haven't totally sold on 360 as I kept thinking of 348/355 in my head
Thats is a good question. In my major I had the Hills Engineering tensioner bearings installed. In 5 years, do I have them inspected instead of just replaced like we do for OEM? Many also change out the spark plug wires and use afterrmarket like Kingsborne. Do these need to be changed out again in 5 years or just inspected. The waterpump was also rebuilt. Does the waterpump need to be rebuilt in 5 years again even if the mileage doesn't dictate so? I would think that many of these would be just inspcted and replaced if necessary rather than just redoing everything again in 5 years. Main issue is for the water-pump... if it fails, it is hard or near impossible to replace with the engine in.
I think a big part of it is harmonics with the chains, especially at stratospheric rpms. The 430/458 engine is a completely different design from the 3x8/355/360 engine. As to reliability, there are MANY chain driven engines with reliability issues - I have experience with the BMW engines that have tensioner and guide issues often times necessitating replacement after 10-15 years (seems to be more age than mileage related - plastics in the guides). That's not cheap nor easy, especially if the guides disintegrate. There are plenty of others and a lot of them are engine-out to do (ford explorer with sohc v6 was at my buddy's shop 2 weeks ago for this very issue - the PS timing chain is on the back side of the engine so it has to come out). I don't know how much of that is down to maintenance (or lack thereof) or abuse on those cars, but in the case of the BMW's with owners that are pretty fastidious about maintenance, it doesn't seem to matter too much.
Another point of view: look at what drives the rear wheel of most motorcycles, if not a shaft. Belts are quieter, cleaner, and plenty strong.
