Some have a small hole, some have a jiggle valve in the hole, others just
have a small nick in the seal between the moving and fixed parts, see
http://www.mgb-stuff.org.uk/thermostat.htm#4. Less to do with bypass than
air-lock bleeding, the bypass port is in the head below the thermostat, so
the pump can circulate coolant through the block and head to prevent
hot-spots while the system is warming up.
PaulH.
----- Original Message -----
> Quick question about thermostats. Does the MGB thermostat require a small
> hole in the outer edge of the thermostat (I"m assuming to serve as a very
> limited bypass)??
|