On 1/7/2012 5:15 PM, Evan Mac Donald wrote:
> Are they BOTH dead, or have I missed something? It should be fairly obvious,
> shouldn't it? The movements are not glacial, or the engines would overheat,
> right?

Actually, they do move pretty slowly. I have an AC engine, but assume
the WC uses the ubiquitous wax pellet type of thermostat. There's a
small round cylinder on the engine side, inside is a pellet of wax made
to melt over a specific temperature range. As it melts, it expands,
pushing a rod to open the valve plate against spring pressure. The rated
temperature is where they first begin to open, they don't open fully
until the temperature is 10-15F higher.