Circulating Pum Inlet Hose Temp

[evantful]

Quick question. My 5.0GI PWTR was not getting up to temperature during its first run, it did this last years. Would get up to about 130 degrees on the gauge and no higher. (Just head this off, I have never had a bad impeller that lost vanes)

So I replaced the T-Stat and cleaned up the T-Housing. Fire it up on the hose to check for leaks and see what happens. Seems to slowly get up to operating temp and holding fine, but I noticed while I was touching the hoses that the big inlet hose to the Circulating pump (not the raw water pump) seemed hot to the touch. Is this normal?

Risers and manifolds are nice and cool, plenty of water coming out the back

 

[alldodge]

I would only be concerned with it IF the motor started to over heat. The Circulating pump, moves (sort of pumps) water around in the block, so that water will get up to the temp of your thermostat. Just a bit hotter then what you would feel on the exhaust, and your on a hose

 

[evantful]

AllDogdge, after posting I read up more to understand how the water flows through. The Circulating pump hose should be "hot" as the water flowing through it is water thats being continuously circulated through the block, ideally at operating temp. My whole understanding of water flow for the engine was backwards.

Water from seawater pump comes into themorstat housing > enters Circulating hose > Circulating pump up from the lower block up into the intake then water leaves through front intake opening > enters thermostat housing > enters circulating pump hose and water flows through the system again.

What happens exactly when the thermostat opens, does it allow water to leave or more cool water to enter the loop?

 

[alldodge]

What happens exactly when the thermostat opens, does it allow water to leave or more cool water to enter the loop?

Yes, when thermostat opens it pushes hot water out around the thermostat and allows cooler water to come into the block

 

[Scott Danforth]

What happens exactly when the thermostat opens, does it allow water to leave or more cool water to enter the loop?

it does both, as the thermostat opens the incoming pressure from the cold fresh water coming into the system expels hot water to be mixed in the T-stat housing with colder water which then exits via the manifolds / risers, and ultimately out the back of the drive with the exhaust.