FYI: Timing belts again! REad this!

Ignoring the sacreligous statement linking Toyota with the Honda S2000 engine, the change interval for Honda Timing belts is 7 years or 105,000 miles (some models are 90,000miles). Honda has a longer service interval than most Japanese manufacturers, which usually recommend a 60,000miles/ 5 Year interval.

It's common for belts to go longer than this, but in my experience not much longer. A typical Toyota MR2 Turbo belt will fail around 75-100,000 miles but I've never heard of one failing at less than 60,000miles due to age. It's quite common for owners to run them until the belts break as it's a non-interference engine so there's a reasonable amount of data to go by.

 

Has anyone looked at doing a polychain conversion. They would last forever. This is what Harley uses for their main drive belt to the rear wheel on new bikes. We had a machine installed where the customer dropped a bolt through the drive trian and it knocked a hole in the belt breaking about 75% of the area and the belt ran for 2 more years before the customer finally replaced it on a PM not beacuse of failure. Gates claims that they have at least a 10 times safety factor over the design spec. which makes them about 7 times as strong as the exisiting F car belts. It would require pulley changes also because it is a uniquie tooth profile.

 

Has anyone here done a 360 belt change by themselves? (I'm not talking about any mechanics on this site who may have done many).

Is it a DIY job for a fairly competent basement mechanic? Any special tools needed? Does the SD-2 need to reprogram the ECU afterward?

 

Mine too but on the 512 and on some other cars with similar change requirements, I found failed tensioners which would have resulted in a belt failure before the belt itself failed.

 

Is there a reason why Ferrari uses interference engines? Do they have any advantages over non-interference engines? The disadvantages are certainly huge in case of belt failure.

 

Hi Solly,
The interference come's from the engine designer,he has not much choice but to cause damage during belt failure,
When the valve's exit the head surface to block they trespass in the piston area so when the belt/chain fail's all hell can break loose,good question-do they have any advantages over non inter engines yes and no depends on the car the engine lives in and whats expected of it,high RPM can be a good candidate for the valve's to enter the cylinders and other factors like how wide or narrow the valve angle is but then it get's to complex to imagine what goes on in these guy's head's,wouldnt mind a chat with PAOLO MARTINELLI for a few years if anyone's got his phone number LOL,

cheers
Dale.

 

Just so I get this right- non-interference engines: valves remain in combustion chamber, away from pistons. Interference engines: valves extend into bore. But if timing belt has constant positive pressure on valves, if it breaks, wouldn't valve springs immediately return all valves to closed position? Or does timing belt act on camshaft which might leave some cams in the down position (valve open) when the belt breaks?

 

Just because the belt breaks doesn't mean that all valves get to jump to their closed positions because of the return springs! The camshaft is still there forcing some of the valves to stay open.

 

Watch out for that rubber failure ... can be more expensive than a full engine rebuild

Not up to speed with the term polychain. Last time I looked at a Harley it had a round tooth belt, like a timing belt driving the rear wheel. FYI: Most modern timing belts use the round tooth design as it is superior to the old square tooth.

I would like to explain Interference engine better.

Interference engine means that the valves can hit the piston if not correctly timed (ie. camshaft stops rotating). It has little to do with whether the valves extend into the bore or not ...

Basically the reason Ferrari builds interference engines is because they are chasing high compression ratios. This means that you do not want to have huge pockets in the pistons to ensure the valves will never hit the pistons ... because that will reduce your compression ratio.

As Ferrari put performance first, you are supposed to maintain your car. As Toyota put reliability and cheap running costs first ... if this should happen then a cheap repair is the go.

Pete's opinion

 

Here's Ed Gault's alternate timing belt system for 308s:

http://www.ferrarichat.com/discus/messages/256120/2273.html

It uses a modern HDT-2 Highly Saturated Nitrile Synchro-Link HT round tooth belt, larger diameter tensioner, & double flanged pulleys.

In spite of all the discussion of people wanting longer lived belt systems, Ed had a hard time selling the 10 systems he'd had built. I sure wanted one, but couldn't scrape up the cash at the time as I was still recovering from buying my 308.

Hope to contact him & get the drawings, belt p/ns, etc. so I can make me a system. (Anyone know how I can get in touch with Ed, please send eMAIL to [email protected]).

BTW, I'm still looking for info on the Gates replacement 3x8 cam belts.

 

Interesting. I read some of that thread and while Ed's system is definitely a step forward and an improvement, I do have to agree that the original belt and system works perfectly ... so why change?, just do the maintenance as Ferrari requests. I suppose it could stretch out replacement periods mileage wise, but if you do not use your car I would still replace every so many years myself.

I will add that my experience with Italian timing belt systems indicates to me that they are inferior to Japanese systems in design. The Alfa v6 system jumps teeth and has little wrap on the pulleys. The Alfa Sud system also has little wrap on the pulleys. Saying that I have never had an Alfa Sud engine fail due to timing belt issues ... but I was always scared setting my engine up, and thus probably over tightened the tensioner bolts ...

In conclusion if I owned a 308 and was worried about the old fashioned design I would definitely think about Ed's solution (note I have never seen a 308 timing belt system/installation first hand, but I have seen plenty of other manufacturers, including FIATS {the Lampredi FIAT 4 cylinder is basically half a 308 engine, so I assume the timing belt system is similar just doubled for the v8} and Alfa Romeos) ... and I would definitely put Ed's solution well before any stupid conversion to chains or gears. All I can say to that idea is WHY? ... so you can abuse and miss-treate your engine?

Pete's thoughts

 

and people here say timing belts don't break
ha

http://www.ferrariads.com/cgi-bin/classifieds/classifieds.cgi?search_and_display_db_button=on&db_id=1867&query=retrieval

 

And yet another one for the idiots that refuse to properly maintain their car:

http://ferrarichat.com/forum/showthread.php?p=134354274#post134354274

While I do not know how old the timing belt on this car was YET!! ... I just hope this case and the many others will finally stop people trying to run Ferraris (or any car) like they are lawnmowers that do NOT need maintenance.

You have been warned ... if it happens to you because you did not replace the belts ... I WILL be saying I told you so, and I will be one of the many coming along and offering you 10% of the value of the car (one has to assume that no other part of the car received any maintenance too) so we can buy it and fix the engine and enjoy the car properly (including maintenance).

Fools.
Pete

 

I use to work for a manufacture of belting. Believe me if an Acura using a Gates belt can run 90,000 miles, a Ferrari can run longer then 4 years. Ferrari recommends 3 years. Norwood, a well know Ferrari service center recommends 5-7 years. This is more realistic in my book. I've personally changed timing belts on a lot of cars including 328, 348, 355, and 360. I promise you they will go longer then 3 years. Why do they not recommend this for Honda drivers...? Because with a Ferrari they can fool you into spending more money. Also, how many Ferrari owners work on their own cars? My guess is not too many (and I'm talking about doing major services). So, for most of us we trust the dealer which in most cases we shouldn’t!

Just my $.02

 

I know of at least one Honda that threw it's belt before the prescribed mileage. However, since valves don't hit pistons in it, no real consequence. Manufacturers of appliance cars like Hondas have an incentive to keep maintenance costs looking as low as possible to compete with other appliance makers. The answer may be somewhere in the middle

Dave

 

....nevermind.

Wow. This is a REALLY OLD thread...

 

Will this issue ever be resolved?

The belt situation seems to be analagous to the Ford Vs. Chevy debate.

Someone well-informed please step forward with the final word on belt life?

 

Ferrari has resolved it...they've gone back to timing chains.

 

Don't like changing belts? Do what I did. Buy a Lamborghini.

 

Where you have to remove the engine to change the clutch. It's all fun...

 

Yeah, but I never lie awake at night worrying about whether my clutch might suddenly let go when I start the car and destroy my engine. Gotta love that tractor technology.

 

Ed Gault's system was good and he used his own personal 308 as a test bed and used modern "off the shelf" "Honda" belt drive technology. I think his sales problem was that the system was only for a 2V engine and he did not have access to a 4V for a test bed. Ed, has since sold his 308 and sadly left the board. He was a professional mechanic with an operating shop and was even willing to do the conversion himself for those that wanted to get their 308 to him ( who knows, maybe he still will? me talking not ed!). He was also a really nice helpful guy, (very much like our own verell)!

 

I got an e-mail from Procter & Gamble who makes my shampoo. They should I should lather, rinse, REPEAT. Do you think they want me to buy more shampoo?

 

it's funny, i came up with a similar idea and added the adjustability. i don't think the sales probelm was that it was limited to 2v's as i have the setup for early 2v~4v engines. but a lack of interest, most agree the belt changes seem to be to frequent but most likely are afraid to change. "the devil you know is better then the one you don't" i guess.

i had a hard time getting just 10 people to sign on to keep cost down, hopefully with the recent clamor for better and the pulleys getting out into peoples hands it will change.
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For the most part, it is safe to say that Ferrari cam belts don't break. They fail by stripping the cogs or teeth off of the backing. Yes, I have one on hanging on my garage wall at home with about 10 teets stripped off ('83 Mondial QV). Repairs we abut $8500 at FoH. We replaced valves and guides on both banks even though only the forward bank's belt failed. Fortunately, no pistons were damaged.
The interesting thing is; Upon examination, many other teeth were starting to fail with small partings at the edges. This condition was a disaster waiting to happen. At the time of the failure, I was driving about 45mph, low stress and at moderately low revs (3500rpm-ish).
Age of belts: 15 years (original equipment); Miles on car at the time: 35k or so.
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Another case: I now own a '79 308GTB with belts last changed in 2000. Sadly, the car hasn't been used much since then (1500 miles or so) but I am about to put it back into service. I will change the belts first. Part of the reason for the change, on top of the 6 years-of-age thing, is that this car was the topic of two (2) UFI oil filter failures. Remember those from about five or six years ago? Yes, my belts have been SOAKED in Mobil1 twice - if cleaned within hours of the spill. So what damage might the oil-soak have done to these almost-new belts? Don't know. As I said, I will change the belts before putting the car back into service.
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best regards,
rick lindsay, #28133, Houston, TX