1998 550 Maranello "sorting" thread--DIY

Pete I for one benefited from your bearing issue. Mine failed recently and through Ricambi acquired the additionally inspected bearings. For this I thank you!

The one that failed only had a couple thousand miles, was not the questioned version, was 3 years post last belt change, and was throwing grease in addition to the common bearing failure noises. Both were replaced.

Bill
FL

Thinking about this post, will add that my maintenance records indicate that these may have been the original tensioner bearings.
2002 575 replaced at 11,800 miles.

 

ete: Could you repeat the cam belt tension measurement with the new 612 type belts?

Is it 330-335 Hz per bank (adding the two longest sections of the belt)?

Thanks

 

Got it, thanks.

 

So here's a conundrum. If I purchase the bearing outside the Ferrari supply chain, and have the labor done by my authorized dealer, and something goes wrong (as has happened recently to other fchatters), then the dealer can hang the blame on my "non Ferrari" sourced parts. That's what happened with allan recently when his cambelt jumped forward and chewed up his belt covers.

However, if I buy the parts from Ferrari, then I'm potentially (likely?) putting inferior parts into my car.

 

Yup, unless they have someone competent to inspect the bearings.

 

Why not have a "true" tensioner like with chains?

 

I like your straight forward questions!

Why not indeed? - every Japanese car on the street has an automatic tensioner that works, and they have 100K intervals for changing the belts, tensioner pulleys and tensioners. Why can't a Ferrari have the same?

Let's come up with something.

 

Thank you.

Wouldn't an automatic tensioner like the one you mention be the ultimate solution for this? Perhaps a task for Helms?

 

Somebody makes a chain kit for the 308, but not for any of the V12s that I have seen. Ferrari changed from chains to rubber belts when the transition was made from the Dino 246 GT to the 308 GT4 in 1973. The V12s retained chains until the 456 was introduced in 1994, but the flat 12 Boxers and TRs had belts, also from about 1973.

The reasons for rubber belts were simple, quieter operation and no adjustments needed because of relatively frequent moving part replenishment. Dino chains started to have problems at around 40-60K miles, the V12 chains seemed to last longer. Both of those chains were manually tensioned because reliable automatic tensioners were not available in the 70s. Interesingly, the Maranellos have a chain driving the oil pump, but this is a much shorter and simpler chain than that required for DOHC drives.

Starting with the Enzo, Ferrari reintroduced chains with automatic tensioners and those quickly migrated to the F430 and then the 599 with its Enzo derived engine.

If you want a V12 with a chain, 599s are widely available, especially if you like black.

 

pre-2000 Chains have a higher amount of stretch over the service life and messes with timing. Ferrari has not such a great rep with tensioning the chains it does us like the 348's. The aftermarket SRI had to fix that. I don't think going back to chains was viable until electronics and variable valve timing could be regulated. How much of that on a high strung motor is performance and how much is mandated by smog I don't know. I'm sure good chains could have been designed but what was cheaper for Ferrari to do probably ended up in the cars. The 550 is one of the last of "what you set is what you get."

 

Very interesting.

I own a 456 and plan on keeping it. There are many V12 with "chains" - but none that I own.

I understand that putting on a chain would be very complex, but the question, and perhaps the possible solution, would be to develop an 'automatic tensioner'.

From what I have read on this forum, our grand contributor David Helms has invested a lot of time and effort in researching what makes belts fail (surface rust, failed fences, bearings, etc.)

It would be interesting to know why he did not go the way of developing such a tensioner, as belt tension should play a much more determining role as the cause of belt failure -

 

After just a quick search, there are several models of cars that originally came with "manual" tensioners, then the OEM upgraded to automatic tensioners for later models to fit without changing the front timing cover, so perhaps something similar could be done for our 456/550/575 models.

SKF seem to favor clock spring type tensioners for their solution, while the Japanese favor hydraulic pistons with internal coil springs. While I know & like the Japanese tensioners, I'm thinking an SKF style damper is more compact, and might have a better chance of being adapted.

Or, what about figuring out how to adapt the existing tensioner so it becomes a true automatic style, ie increasing the strength of the spring so it's sufficient, plus modifying or redesigning the support bracket so the pulley can float, the way it should, instead of being tightened down and fixed?

Pete, sorry for the hijack - maybe we should take this discussion to another thread? There are several other threads talking about the tensioner and bearing problems:

http://www.ferrarichat.com/forum/showthread.php?t=349578

http://www.ferrarichat.com/forum/showthread.php?t=348780

http://www.ferrarichat.com/forum/showthread.php?t=332921

 

Always found those reasons for switching to belts arguable. Chains are not noisy compared to the rest of the engine, especially not when the chain is completely at the front and away from the cabin.
What is more important in my view, is that it's a great way to make extra revenue on parts and maintenance and have people coming back to your dealerships , and I always thought that was probably a much bigger factor in the whole equation. The belt setup also takes up more room and is often not less complex than a chain setup. If you look at a 348 or Mondial engine that is especially true, why first have a short chain and then exit the drive from the engine to go to a belt? It doesn't make sense to me from an engineering perspective.

As for reliable automatic chain tensioners, BMW was using an hydraulic automatic setup since the early '60s, as was Mercedes in their M180's and they all worked perfectly. BMW M10 and M30 engines were basically unchanged from 1964 till 1993, and the setup is good for 200k miles without issues.

 

I would think the only complication of the chains would be the lubrication

 

NO WAY, may I ask why you are selling her?

 

That does not sound good. Could be a case of you can only get kicked in the head so many times before you cry uncle? People say panzers are nice...

 

Pete, I figured you were bored now that the 550 is all sorted, and were probably going to buy a clapped out 355 next and sink your teeth into that

Good luck with the sale, and let us know what's next on the project list. I just can't see you not actively tearing into something.

 

Pete I'm curious - how many miles have you now put on your 550 after all the work you've done?

BTW, if any mods are monitoring this thread, I vote that it should be closed & stickied once Pete sells. Pete's done a great job of photo-documenting many of the issues and solutions that we have with these cars, and it would be a great thread to have at the top of this forum to refer to.

 

1. If I were still living in the US, I'd certainly be very interested in your car - it must be the best documented, most carefully sorted out 550 out there! Good luck with the sale and congrats on the promotion.

2. After all that time in the garage, not being spent with your gf, and she's stuck around? May be a keeper!

Best,
Ben