Thermostats

[deppong]

How is a Thermostat suppose to work - I know it keeps the engine at a certain<br /> temperature by blocking the flow of water thru the block jackets - however here <br />is what I think I know. When the engine is cold or below temperature the thermo<br />is closed - does it completely block the water flow from the pump or just partially?<br />If it does it partially how does that work? It only allows certain jackets to get water<br />or is there another way?<br /><br />It does not sound like it works like a car thermostat!<br /><br />Thanks!<br />

 

[Backlash]

Re: Thermostats

It works like a car thermostat. As the thermostat temperature increases, the spring expands, opening the thermostat and allowing water to flow through it.<br />Backlash

 

[Scottj25]

Re: Thermostats

The termostat works by opening and closing in relationship to the engine temp, when closed very little water gets though, but once open it should never close all the way.<br />It will slow down the amount of cool water entering the engine while receoling(?) the warm water the engine already has.

 

[DJ]

Re: Thermostats

deppong,<br /><br />It may help to know that the thermostat is at the end of the water flow. In other words, it's like the spray nozzle on your garden hose. There is always water in the hose, it can only flow through the hose when you open the nozzle.

 

[seahorse5]

Re: Thermostats

Most outboard thermostats have a small groove in the valve seat to bleed off the air when the motor is first fired up and it keeps a small flow of water passing over the temperature sensor in the thermostat for proper operation. Some engines use a small passageway for by-pass water to flow constantly.<br /><br />Check out the Oct. 2001 back issue of Bass and Walleye Boats for a good description of thermostat operation and testing.