[s-cars] Re: Timing belt vs Gears vs Chain

[William Noland]

Nothing wrong with a belt at all -- but, chains and gears will last longer. On the other hand, belts
tend to be a bit quieter. I can hear the chain on my '04 S4, though it's a nice mechanical sound, if
you know what I mean. OTOH, my old (chain drive) VR6 VW (Passat) was so quiet, it wasn't always
clear that the engine was running at idle. When I checked with VW on the recommended replacement
mileage for the VR6 chain, they didn't have a recommendation!

Only gear drive cam in the "stable" is on the '00 Honda VFR800. Not a real apples to apples
comparison, as a motorcycle engine is relatively unenclosed. That puppy "whined" like a sumnabitch,
until I threw on an aftermarket can. Honda started using the gear drive on the VFR's, when timing
belts failed a little too regularly back in the 80's. (Life's a little different at 12,000 rpm.)
VFR's from '02 on have belts, as do most bikes -- many of which rev into the stratosphere.

The neu S4 has a chain, because a belt of similar size just won't hack it. Note the chains on the
Audi CVT. Belts won't take the torque. What's this all prove? Different motors are different?  :-)

Bill Noland






> Gentlemen:  There is nothing wrong with the toothed rubber timing belt.  It is
> light. Is only one moving part. It is relatively inexpensive.  Gears or chains
> are heavier.  Have more moving parts and would be much more expensive.  Do you
> think a chain wouldn't wear and break (into many little pieces of shrapnel)?
> Do you think gears (if you could figure out a way to span about 18 inches with
> them) wouldn't wear and have all sorts of "lash" problems (it would give a
> whole new meaning to "variable valve timing" (it would be randomly variable -
> always a good thing (NOT!))).  Rubber timing belts need to be changed before
> they fail and they need to be protected from outside damage.