Honda Car Forum

Does the 4cylinder Vtec Accord 1994 motor have clearence between the
pistons & valves, or does it self destruct if the Cam belt breaks?

"Peter Humphreys" <peterhum@xtra.co.nz> wrote
> Does the 4cylinder Vtec Accord 1994 motor have clearence between the
> pistons & valves, or does it self destruct if the Cam belt breaks?

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.

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?

"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.

Elle wrote:
> 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.

wouldnt be surprised if ALL honda passports were no interference. its an
isuzu design with lots of GM parts.

SoCalMike wrote:
>
> Elle wrote:
> > 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.
>
> wouldnt be surprised if ALL honda passports were no interference. its an
> isuzu design with lots of GM parts.


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That explains all the negative things that Consumer Reports Used Buyer's
Guide has to say about them . . .:-)

'Curly'