[Spridgets] Question

[Dean Hedin]

Good reading here:

http://www.crxsi.com/articles/read/what-s-best-timing-belt-or-timing-chain-february-2009.htm

"In 2009 model year we see a new trend of car manufacturers moving back to timing chain engine design. 
Many of them rely on a service data and price/performance evaluation for the size of the vehicle.
It is unlikely that general public will know exact figures on timing belt/chain price/performance 
comparison but we all have our own preferences and that may become a driving force for the future engine models."

and here:

http://newsgroups.derkeiler.com/Archive/Alt/alt.autos.toyota/2008-02/msg02133.html


Personally, I prefer a timing chain.  Over the years I have dropped some serious change to replace timing belts.

Changing a chain has never been an issue on the cars I owned that had them, namely, Ford's Cologne based V-6s 
and of course the A-series.

And contrary to what people say, timing is not compromised with a worn chain, assuming the tensioner is in order.


----- Original Message ----- 
From: "Kirk Hargreaves" <khargreaves2 at gmail.com>
To: <spridgets at autox.team.net>
Sent: Wednesday, January 20, 2010 4:36 PM
Subject: [Spridgets] Question


>A Porsche has it's cams driven by an internal chain.  . the same as I think
> about it as the straight 6 Jaguar engines hailing from the 1950's (and
> possibly earlier).
> 
> Many high end cars have their cams driven by an internal chain with a
> tensioner which needs very little maintenance, if any, compared to an
> outside belt drive.
> 
> The Ferrari, and I am guessing the Lambo and other super high end cars have
> their cams driven by outboard belts . . which need to be changed out at
> around 30k miles.
> 
> With the Ferrari, I understand that it is a big process in that the engine
> has to be pulled to change out the belts.  I have read that it can cost up
> to 10k to have the dealer change out the belts in a Ferrari.
> 
> So why would Ferrari, as well as others, go with an outboard belt drive on
> their cams?
> 
> Is it because the system is lighter, gives a better response, or?  I am
> guessing that the thought is that outboard belt driven cams enhance
> performance?
> 
> Just a question that has been in my head for a while. . I never have heard
> anyone explain the theory behind the out board belt as opposed to the
> internal timing chain for driving cam shafts?