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Veloce Today - The Great Cam Belt Controversy

Discussion in 'Ferrari Discussion (not model specific)' started by MondialTCab, Dec 4, 2003.

  1. MondialTCab

    MondialTCab Formula 3

    Sep 5, 2001
    1,020
    Pacific Northwest
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    John Michael Gross
    FYI as posted on Veloce Today:

    Our Cars: Cambelts for the 308GTB QV

    By Pete Vack
    In which we tell you what we are doing, (not how you should do it), why it must be done, parts sources, good and bad, and how much it costs.

    The Great Cam Belt Controversy
    There has been a lot of controversy about Ferrari cam belts. The question is, why do I have to change the belts every 30,000 miles on a Ferrari, when my Honda goes 90-100,000 miles without a change? To make a long argument short, one factor is the cost associated with belt failure; losing a belt in a 308 will definitely result in damaged valves, possibly pistons, due to the close interference fit. The Honda and similar vehicles don't have this problem. Other considerations are the high performance cam lift and spring rates of the Ferrari which put a heavier load on the belts; traditionally poor camshaft seals which result in oil on the belts; and since Ferraris often sit for long periods of time, the belts tend to develop a set, much like tires, from long periods of inactivity. Belt replacement is the first thing potential buyers will ask about, and, lastly, it's obviously good for the dealers.

    I won't recommend any interval, that's for others to do. In my case, the belts were almost ten years old, and on that basis alone well worth changing. I'd do it by the book, or within 8 years, after that. And always better safe than sorry.
    That being said, changing the belts is an easy, no sweat job. If you do it everyday. Belts can be changed fairly simply if the camshafts aren't removed. Here's the cost breakdown if you do the complete job:

    Continue story at http://www.velocetoday.com/lifestyle/lifestyle_30.php
     
  2. ILMAESTRO

    ILMAESTRO Karting

    Dec 29, 2002
    68
    The few Ferrari mechanics I have spoken to in LA have never seen a V-8 car with a broken belt with the exeption of the dealer!
     
  3. Dave

    Dave F1 Rookie

    Apr 15, 2001
    2,722
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    David Jones
    I have seen 4 myself...
     
  4. tbakowsky

    tbakowsky F1 World Champ
    Professional Ferrari Technician Consultant

    Sep 18, 2002
    14,415
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    Tom
    Honda's, Hyundai, Suzuki, Toyota, Porsche(944,928),and many other standard cars on the market have interferance engines. And still there timing belt change intervals are much wider then Ferrari.

    You make good points about cars that sit needing to have them changed more frequently. I have a customer with a 308 and he is the orriginal owner of the car. He has never changed the belts. Car runs like a top,but I would not trust it. He will be doing the service this winter,only at my urging and giving him a good quote on the service.

    As far as the tigher springs and lift..I don't think there that much more radical then a Vtec handa engine, or say the mazda 1.8l 4cam V6. That car also spins to about 6krpm.

    I'm not saying that going longer then specified is a good thing it is not. And as you said the problems a snapped belt can cause are huge. I had a customer who's belt snapped on his 348 and did about 16k damage to his engine.

    But what I really want to know is why the change interval is so small compared to other companies. Is there a specific reason,or is it just to keep the dealers happy and the service bays full?
     
  5. Santini

    Santini Formula Junior

    Oct 1, 2003
    480
    North Carolina
    Thanks for the link. Lots of good info on 308 maintenance.
     
  6. davem

    davem F1 Veteran
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    Jan 21, 2002
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    dave m
    Just to play devil's advocate here. Not many have firsthand knowledge of a Ferrari cambelt snapping, skipping what have you.
    Now take a look at the others cars we are comparing. Mostly cars that are far newer than any 308-328 series. How many ordinary car makes on the roads from the 80's are still out there. Few. My friends Acura Legend snapped at 170k an 12 yrs on the original belt. He also bragged how he beat the car an rarely maintained it.
    Point is as long as belts are free from oil an driven enough so they dont take a set, 7-8 years is probably ok.
    That said i just had a 30k done this year on my Mondial, though records indicate it was done 4.5 yrs ago!
     
  7. cmparrenzo

    cmparrenzo F1 Rookie
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    Mar 3, 2002
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    Chris Parr
    This has been covered alot on here, but here it goes again...

    On a Ferrari it is usually not the cam belt that fails, it is the tensioner that seizes and then the cam belt fails. So EVERY cam belt change should include tensioner bearing replacement...

    I experienced this and $23,000 later I learned my lesson, and this was on a 12,000 F355 that had the belts replaced 3 years prior.

    (by the way, I replace my timing belts and tensioner bearings EVERY year on the F40)
     
  8. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
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    Hugh G. Rection
    I don't recall the stories now, but two individuals had cambelts break on their cars over on FerrariList about three years ago. One was a Mondial, the other a 308...but I can't recall the age or mileage interval, but they were definitely beyond what is considered reasonable and customary....
     
  9. Challenge

    Challenge Formula 3

    Sep 27, 2002
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    Kevin
    Ouch. Twice.
     
  10. 355f

    355f Formula Junior

    Nov 1, 2003
    305
    On your 355 were there any signs that the belt or tensoners were about to expire?
     
  11. ultgar

    ultgar Karting

    Nov 21, 2003
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    Steve D'Gerolamo
    #11 ultgar, May 19, 2004
    Last edited by a moderator: Sep 7, 2017
    We just did the belts on a 355 last night and found all 4 cams way out of time after only 8000 miles on the engine. I'm told that a lot of mechanics simply draw alignment marks across the pulleys for reinstallation without going through the 2hr ordeal of checking & retiming of each of the cams.
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  12. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    6,337
    Can you imagine having to do this kind of timing job with the engine sitting in the engine bay?
     
  13. yelcab

    yelcab F1 Veteran
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    Nov 29, 2001
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    Mitchell Le
    #13 yelcab, May 19, 2004
    Last edited by a moderator: Sep 7, 2017
  14. ferrarifixer

    ferrarifixer F1 Veteran
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    Jul 22, 2003
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    When doing a DTI timing check for the first time on any of my customer cars, I put permanent marks on the crankshaft and on the camshafts. This way, the next time "I" do the job, I can save the customer and myself time because I know the marks are correct.

    I found one exhaust camshaft on an Fchatters dealers serviced 355C to be significantly out of time.

    For lifing of Ferrari cambelts it is necessary to include the average rpm at which they operate. Your average family car with an auto transmission may only average 2000rpm. Your average Ferrari will be more like 4000rpm, so you can half the mileage straight away at least.
     
  15. Smiles

    Smiles Moderator
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    Nov 20, 2003
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    Matt F
    Good point about the higher RPMs used by Ferrari owners.

    Another thought: a lot of people seem to replace cam belts when only an inspection or adjustment is called for.
     
  16. ferrarifixer

    ferrarifixer F1 Veteran
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    Jul 22, 2003
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    NEVER adjust used cambelts. EVER, WITHOUT EXCEPTION.

    Once a belt has taken a set and stretched slightly, any further stretching will cause it to fail. How soon will depend on a million things.

    All you 308 owners out there with worn "plastic" pulleys have had your belts either over tightened or re-tightened.....how much did that cost to fix unnecessarily?

    The later cars with hydraulic assisted "soft" tensioners are less critical, but if fitted properly in the first place, will never need adjustment anyway.

    Inspections only show minimal detail. If in doubt, whip it out.
     

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