"High Tech Misfit" <me@privacy.net> wrote
> Elle wrote:
>
> > It is an interference engine, so the pistons may indeed run into the
valves,
> > doing thousands of dollars of damage, when the timing belt breaks.
> >
> > See the guide at the following for which engines are interference:
> >
http://www.gates.com/brochure.cfm?br...&go=preset663G
> > ates
> >
> > Damage is not guaranteed. It is simply possible. It does occur.
>
> It may be possible that the higher the engine is revving, the greater the
> chances of piston and/or valve damage. My brother once owned a '95 Ford
> Escort with a belt-driven interference engine. The timing belt broke when
> he was stopped at a stop sign, but fortunately there was no damage. It
was
> the mechanic who replaced the belt who suggested that the low idle
possibly
> saved the engine from being damaged. Does this theory sound realistic?

Yes. It takes less time to bring an engine at lower RPM to a stop than one
at high RPM, once the power from combustion is removed.

Off the top of my head I'd add that the gear probably has an effect, too.
Higher gears are harder to turn than lower gears, for the same RPM. So I'd
imagine the higher gears slow the engine down more quickly, following a TB
break. That's what one wants: For the pistons to stop moving as soon as
possible.

I discount the higher mass and so inertia of 5th vs. 1st gear, but I could
be wrong to do so.

Someone could talk me out of this. It's just my best guess. Groups.google
talks about the worst case being for the timing belt to break at highway
speeds. This supports at least your theory.

Though I'm sure it's been noted before, for the recent record: It appears
that only certain Honda Passports have /no/ interference engine. All other
Hondas are interference.