Has anyone had any experience with these belts, or any other "upgraded" timing belts? I'm looking for better replacement belts for a 355 if there are any. Ferrari 184986 Timing Belt (2 per car)
I have used non OEM Dayco belts on my Duc999 (kevlar) and Mondial Just as good as the original Will last much longer than 2 yrs
I have not seen any manufacturer's guarantees that kevlar belts will last longer. It seems that the recommended replacement intervals are actually the same as for "standard" belts. They don't seem to be anything "revolutionary". Some consider kevlar belts as still experimental. Some think that, since kevlar stretches much less than the other materials used in timing belts, the kevlar belts will cause higher stress on the water pump and tensioner bearings as the kevlar belt will not follow the engine heat expansion and will get over-tensioned when the engine is hot.
The standard belt is Dayco 94984 (111RHPN280HT) The belt has a PTFE layer on the teeth This is a very high quality belt designed to be used in common rail diesel engines These demand a lot higher belt strength than traditional engines as the 355/360 I am not familiar with this other 'kevlar' belt for the 355 Can you give me the Dayco number of it?
The same seller is also selling a belt for 348, in a box that looks the same as the 355 one, but does not call it "kevlar" (no "Kevlar" words on any of the boxes). Eurospares are selling a Dayco belt for 348 with white teeth (I guess that's the PTFE coating) with a marking "High Tenacity" on the box at GBP 22.
The 355 OEMbelt is HT, I bought it from Superspares recently The 348 OEMbelt is not HT I cannot find the updated belts on the Dayco website Can you give me a dayco number
The issue for our cars and the major is not the belt life as much as the tensioners, alt bearing and water pump service. At least for me and my 348SS. Every major so far has shown the belt to have very little wear, but those other items always need attention.
So spending more money on a Kevlar belt reduces cost? How? You going to run 7, may be 10 years, between belt changes with a Kevlar belt? As Vassallo notes above, the real reason to pull the engine every five years is for all the other crap that has failed. The belt is never the actual reason...
I'd be all for a better belt. Regarding bearings, let me put a little perspective into this: I have CNC machines running 12K RPM's 10 hours a day. One of my older machine is like 14 years old now. Never had a bearing failure. Yes, the bearings have a lube system. But the thought that bearings crap out every 3/5 years (especially the alleged better aftermarket) just does not make sense. (Given most of us don't clock that many miles) Only in a Ferrari
I'm 2.5 years into a new building that has A/C. Prior location did not. The machines generate so much heat that my heating bill in January/ February is like $50 per month (sub zero outside temps). No lie. Don't ask me about my electric bill
I've long heard that it's the bearings that fail, and not the belts. But rifledriver has posted here that his experience is that bearings almost never fail, but belts certainly do. Granted, that's only one data point but it's a very solid one based on his extensive experience. I'd be very happy to use an upgraded belt (or belts) if they were available. Even if you didn't extend the service interval the extra peace of mind would likely be worth it, depending on the price premium for the better part(s).
Mike, I agree. Also, I'm for better: belts, bearings, etc. But I Want data. If one bearing is supposed to be better than another, I was test data from a third party lab. I don't want "buy x" because. Because it's popular....
Very much agreed, Dave. Especially when it comes to belts, where it's so much more difficult to demonstrate the differences. I think Hill Engineering has done a decent job of explaining why their bearings are better than stock and I'd want the same level of understanding of why a given belt was superior before signing on to test it. That said, if it came from one of the biggies like Dayco or Gates it'd be much easier to believe the claims. Still, nothing beats experience.
I see what you mean but that falls under the heading of experience in my book. One of my favorite sayings is, "The difference between theory and reality is that in theory they're both the same but in reality they're really quite different." You and I have both been around long enough to know that an idea that seems brilliant in concept often contains unexpected pitfalls just waiting to reveal themselves. No matter how you get there, real world data beats paper promises any day of the week. Gotta give the gremlins an opportunity to show themselves.
Mike, running tests in a lab is not theory, it's good product testing. The problem with undocumented experience is just that. It's non factual (often) under non standard testing methods
That's what I was saying in my first sentence. I can see your point if you're referring to one or two data points, but I will take the observations of someone who has been in the business for a very long time over lab testing since long term field experience can reveal issues that don't show up under test conditions. But I think we're getting more than a little off topic.
With all respect to Brian, I could show him a stock bearing set that failed at the 5-year mark. Forgot which one of the 2 tensioners it was, but it came apart when we did the major in a way that could have been catastrophic. Ever since my Hill upgrades, I am 100% confident in the bearings, but I won't test fate.
Vince, why show Brian? Show us! You know, there is always the isolated case where something fails and in typical FChat form it becomes an "they all do it".
True John. I've asked for HE bearing test data... Nobody posted yet. I would think it would be a positive to prove the reasons why something is better...
As a sidenote, that's the conflict with the GCK. It works in real life but fails in theory. Just me alone have 5 years on GCK waiting to see a failure. I haven't. There is a whole thread on timing belt deciphering and the reasons why the cherry picketed Ferrari branded belt is better than the blue stripe dayco. I think Ferrari is only sourcing kevlar belts. I don't know if the blue stripe dayco is a kevlar belt or not. The cost difference for all the work you have to do to change the belts and time the motor is just not worth haggling over. I used to use dayco blue strip when I perceived no difference. But after I was taught why the ferrari branded yellow stripe is better that is all I use. In fact I only buy them from Ricambi for the freshest dates too. That said their are plenty of cars running blue stripe dayco just fine. In the old days that is all we had. There is no statistical difference I know of where one belt is better than the other during the service life. We do know on the V-12's, Ferrari dramatically extended the service life of the kevlar belt. That was probably also done with the V8's but I have only seen the Ferrari TSB on the 12's. Dayco says you can use an 8 year old manufacture blue stripe non-kevlar belt for a new installation and run it for the service life. My question is why bother? There is a huge difference in bearing quality. In a service life the Ferrari bearing is just as good as the hill. I have seen very very few bearing failures. And what failed 1st is really hard to say. Cars that did fail usually had multiple maintenance issues too. The hill bearing is like extended life antifreeze. It has got way more reserve capacity and can take the shocks of abuse like tracking or garage queening or big swings in belt tension (a whole other thread of disagreement). Again cost here is not an issue. And I'm not sure what is current with Hill but there was a time the Hill bearing was rebuildable! That was like gold and made the cost of ownership way less than buying ferrari bearings which over time have only grown in inferiority. The Ferrari 170787 timing bearing comes to mind where Ricambi was the only one who would not sell even when there was no substitute. Daniel refused to sell known cr@p even if it was the only cr@p in town. If you did not know anything about Ferraris you could just buy parts from Ricambi and rest assure you would have the best parts available and not have to even worry about discussions like these.
Carl, the difference between you and I am Johnk is we make decisions on factual, scientific data and not unsupported popular opinion. If Hill can present data to me that supports better bearings, I will bow down and buy theirs. But I won't do so because it's FChat popular. I have OEM bearing in my F1 and I regularly hit 8500 RPM's with no issues. Dave Helms is a brilliant guy IMO but if his kit had new tin pins it would be just as good, well, actually better.
