Belt vs. chain for cam drive

[Robert Myers]

Conversely, Dave, I had a 1969 Dodge Charger with a timing chain.  It
jumped a tooth in 1972 and the car was dead in the water.

BTW, this was the very car "given" to Joe Namath when the Jets won Super
Bowl III.

At 10:06 AM 5/8/02, David.Ullrich at ferguson.com wrote:

>You have a point, but have forgotten just how long timing chains last. If
>engineered properly they will last as long as the engine. Lets take for
>example the good old Chevy V8 in either 305 or 350 CI displacement. That
>engine has a timing chain and nobody EVER changes them. I'm also into
>Impalas (I have an 85 SS and previously had a 78). I've never heard of the
>timing chain ever breaking or skipping a tooth, ever. On my previous 87
>Impala with a 305, it had over 425,000 miles on it when I finally replaced
>the engine. The timing chain had NEVER been touched. Sure, it had
>stretched a tad and there was a bit more play in the timing, but I could
>still tune it to within 1/2 degree. The 85 SS has a HO 255 HP 350 has
>almost 150,000 on it and the timing chain hasn't been touched and hasn't
>even stretched yet. So, if Audi did their homework, the timing chain
>shouldn't ever have to be touched, at least until the engine has to be
>pulled for a rebuild...
>
>Dave
>
>1987.5 Audi Coupe GT "Special Build" 2.3 - Anthracite Black
>1998 VW Passat GLS 1.8T - For Sale CHEAP
>
>
>-----Original Message-----
>From: Mike Arman [mailto:armanmik at n-jcenter.com]
>Sent: Wednesday, May 08, 2002 4:17 AM
>To: quattro at audifans.com
>Subject: Belt vs. chain for cam drive
>
>
> >From those pages:  "The toothed belt previously to be found on the
> >engine's front end has been replaced by a chain drive to its rear."
> >About Time, hoping they do this to ALL their engines.  No ultra pressure
> >hydraulics, no timing belts, etc.  Yeah.
> >
>
>
>
>I'm not entirely convinced that the chain drive is an improvement,
>especially as it is located on the rear of the engine, where there is NO
>access to it unless you pull the engine (and tranny).
>
>My perception of the problem is this - since the chain is out of sight, out
>of mind, the only time any attention will be paid to it is when it breaks
>or skips some teeth, and then the damage to the rest of the engine will be
>horrendous. Take a look at the W-12 picture, and you can just see the chain
>at the rear of the engine . . . and notice how complex that engine is.
>
>At least the rubber belt is fairly easy to change, and (at least on the I-5
>engines) not expensive. Heck, we change oil, don't we? Changing the belt
>every 60,000 miles is just good preventive maintenance. Changing the chain
>is going to be a HUGE job, and like as not, won't get done until it breaks,
>and then the entire engine will be scrap metal.
>
>Result - Audis will go down in value, quickly. Why? The "older" ones will
>be in the junkyards because no one will pay the huge amount needed to fix
>the engines - and by "older", I'm talking about cars that may be only five
>years old! 100,000 miles in five years is no big deal any more - and here's
>a car which is five years old, and needs $15,000 worth of engine work to be
>a $20,000 car. Ouch.
>
>As the word gets out that there are LOTS of late model Audis in junkyards
>because once out of warranty, no one can afford to fix them, the resale
>values of the ones that still do run will plummet, and the depreciation
>will increase drastically.
>
>Don't get all excited if this scenario sounds familiar - the last time it
>happened, there was NOTHING wrong with the cars, and it almost killed Audi
>in the US market. This time, there will be a great deal wrong with the
>cars, and the non-existent resale values will be based in hard financial
>fact, not television fiction.
>
>I think Audi is making a mistake by not considering the entire life cycle
>of their product. Once the warranty is expired (and sometimes even while it
>is still in "effect"), they want the cars to simply evaporate off the face
>of the earth, thank you. As a result, older Audi's are tough to sell and
>don't bring much money, and this hurts the sales of new ones because people
>KNOW they are going to get hosed at trade-in time.
>
>Mercedes has a slightly smarter approach. They seem to be interested in
>making parts and service available for anything they have ever built, and
>as a result, there are more "classic" Benzes running around. People then
>say "Hey, those cars run forever and hold their value, too - I want one!",
>and a 90s vintage MB which cost just a little more than a 90s vintage Audi
>when new sells for a LOT more now, and it isn't really a better car.
>Example: compare the current selling prices of a 1991 190E and a 1991 90.
>Mercedes is thus perceived to have value, and they get ferocious top dollar
>for their cars, wheras Audi, whose flagship cars are similarly priced, has
>a tough time.
>
>Solutions - 1) design for durability beyond the day the warranty expires -
>this supports the market and price point for the cars still IN warranty. 2)
>Support the out of warranty vehicles. A pristine twenty-year-old example of
>your marque is a darn good advertisement, and you can make money selling
>all those parts, too!
>
>And I'm SURE Audi isn't listening, but I feel better now . . .
>
>
>Best Regards,
>
>Mike Arman
>
>
>
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Bob
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  Robert L. Myers   304-574-2372
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