What is the benefit of timing belts over chains...or vise versa? | FerrariChat

What is the benefit of timing belts over chains...or vise versa?

Discussion in 'General Automotive Discussion' started by Devilsolsi, Aug 28, 2008.

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  1. Devilsolsi

    Devilsolsi F1 Veteran
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    #1 Devilsolsi, Aug 28, 2008
    I have always sort of wondered what the advantage of going with belts over chains, or the other way around is. Does it vary based on the type of engine? Some companies have been using chains for a long time, others still use belts, but yet there are still some that use belts on some motors, and chains on others. Anyone know how this gets decided?
     
  2. swilliams

    swilliams Formula 3

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    #2 swilliams, Aug 28, 2008
    belts use less hp I believe but are more maint. prone. Timing chains are more reliable but use more hp.
     
  3. Ispeed

    Ispeed Karting

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    #3 Ispeed, Aug 28, 2008
    I have a P 928, and the story behind the 7' long rubber toothed timing belt is that the all aluminum block expands a lot when hot. It works well enough, but no doubt a weak point of these cars. IF a mechanic always replaces all the rollers, bushings, and rebuilt the tensioner correctly it will always be fine.
     
  4. PaulK

    PaulK F1 Rookie
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    #4 PaulK, Aug 28, 2008
    Wouldn't belts be more suited for high rpm engines than chains?
     
  5. pks41805

    pks41805 Formula 3

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    #5 pks41805, Aug 28, 2008
    Belts are more quit. Better of NVH.
     
  6. solofast

    solofast Formula 3

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    #6 solofast, Aug 28, 2008
    Belts are cheaper for the OE. That's why they get used a lot.

    They are quiet and reliable, but do need to be replaced from time to time, although most cars get a lot more miles per belt than Ferrari's....

    Chains stretch and the timing can change as a result of that.

    Belts actually require more power than a properly done chain, and at speed they are pumping out air and can be noisy if they are too wide.
     
  7. LightGuy

    LightGuy Three Time F1 World Champ
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    #7 LightGuy, Aug 28, 2008
    Chains = the right way.
    Belts save the OEM $ and increase the bottom line in the service department. I'm convinced the Ferrari service department would not be economically feasible if not for belts.
    Gears ? Now were talking !
     
  8. Tony K

    Tony K Formula 3

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    #8 Tony K, Aug 28, 2008
    Belts are better for: quieter, heat expansion, traversing longer spans from crank to cam, less moving mass

    Chains are better for: stronger, less maintenance


    Either only works as well as its tensioner; tensioners can fail on chain engines, too (i.e. early SM/Merak and 70s 911s).
     
  9. gougoul

    gougoul Formula 3

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    #9 gougoul, Aug 29, 2008
    Gears are the ultimate stuff for very high RPMS and are (almost...) 100 % safe
     
  10. Devilsolsi

    Devilsolsi F1 Veteran
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    #10 Devilsolsi, Aug 29, 2008
    What engines are set up like this?
     
  11. Tony K

    Tony K Formula 3

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    #11 Tony K, Aug 29, 2008
    Pontiac's "Iron Duke" four cylinder (i.e. Fiero) has the camshaft driven by a nylon gear! :D
     
  12. pks41805

    pks41805 Formula 3

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    #12 pks41805, Aug 29, 2008
    And was crap. Gears would wear and clog the oil pump.
     
  13. mls

    mls Karting

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    #13 mls, Aug 29, 2008
    Maserati MC12
     
  14. Dale

    Dale F1 Veteran

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    #14 Dale, Aug 30, 2008
    Gear driven cams is by far the best way to drive camshafts but the downside is its expensive.
     
  15. gougoul

    gougoul Formula 3

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    #15 gougoul, Sep 1, 2008
    Noise is also a problem.

    Costs probably too (yeah carmakers hate shelling out a cent or two)...
     
  16. technom3

    technom3 F1 World Champ
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    #16 technom3, Sep 1, 2008

    Bentelys use gears, and from what I have read, due to this arrangement are red line limited to about 5k rpm (im talking about real bentelys, not the VW ones LOL, i would love to even have a CGT)

    anyways, i had no idea the MC12 had this set up. If the mc12 has it, why doesn't the enzo since they share the same engine?

    Also, most diesels have gears
     

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