<<Timing chain is better in my opinion. Why do they use belts, anyway?>>
Noise, vibration, and reduced mass. Remember, we're talking
overhead cams here, not OHV. (On OHV, the noise and
added weight are not as great of a problem due to
packaging. Still, I had one of the infamous odd-fire
3.8 V-6's with the nylon timing gear guaranteed to
fail at 60k!) IMO, the benefits of the OHC design
are well-worth any of the inherent drawbacks.
While some older OHC's used chains, they were actually
more trouble than belts (only hearsay, I have no
direct experience here). The worst part, of course, is
that most high performance engines are "interference",
meaning when the belt breaks, pistons hit valves and the
car's owner develops a serious leak in his bank account.
It's cheap insurance to consider the belt as a consumable
and replace it every 50-60k (or every 5 years, whichever
is the shorter interval.)
Bill Elliott
Lake Mills, WI
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