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| | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 |
On my 261 water pump there was an extra hole/fitting on the water pump and an extra hole/fitting on the thermostat/outlet housing.
I have seen the holes used in a different ways:
1. Plugged (and not used)
2. Used for extra heater lines in school buses.
3. Used to heat an intake manifold that is not attached to an exhaust manifold.
4. A line is run from the pump to the thermostat housing (the engine might warm up more slowly but this gets fluid flowing into the head before the thermostat opens - a hole in the thermostat does this but allows less volume through and the engine would warm up more quickly).
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