Timing belt question, 99 Honda Accord DX

In article >,
"Forrest" > wrote:

> "Elle" > wrote in message
> ...
> >A person at Honda-tech.com a few years back tossed out that, when a TB
> >breaks, it is possible for the cam to be in a position such that all the
> >valves are shut.
>
> I'm no expert on any of this stuff but that doesn't sound possible. I would
> think that at any one time, the only cylinder with the valves closed would
> be the cylinder on the compression stroke. While it's doing that, the
> opposite cylinder, on a 4 cyl engine, is on the exhaust stroke with the
> exhaust valves open. Check out this video.
> http://www.youtube.com/watch?v=Hhc6x...eature=related

Impressive video, thanks.

And thanks to all those who contributed in this thread. I will have
the TB changed soon. My thinking: I'm hoping to have this car for
another 10 years. Obviously for safety's sake I need to have the
TB done sometime in that period, and right now makes the most sense
given that.

"Forrest" > wrote
> "Elle" > wrote
>>A person at Honda-tech.com a few years back tossed out
>>that, when a TB breaks, it is possible for the cam to be
>>in a position such that all the valves are shut.
>
> I'm no expert on any of this stuff but that doesn't sound
> possible. I would think that at any one time, the only
> cylinder with the valves closed would be the cylinder on
> the compression stroke. While it's doing that, the
> opposite cylinder, on a 4 cyl engine, is on the exhaust
> stroke with the exhaust valves open. Check out this
> video.
> http://www.youtube.com/watch?v=Hhc6x...eature=related

Right, I follow. Perhaps the valves could all land in an
intermediate position when the cam stops. I would have to
think about it more.

I did notice recently at the yard that the "valve reliefs"
(those indentations on top of the pistons that I am not sure
all or any Hondas have) may certainly be assisting the
valves' protection when timing is lost. For all I know
whether damage occurs may depend on so much: the engine
temperature (higher temp = less clearance?); carbon buildup;
which Honda engine we're talking about; manual vs. auto
tranny.

I wonder if the valves can even be pushed shut (without
damaging them) for a number of cycles as the engine comes to
a stop. But this may be naive on my part.