Thermodynamics?

[Hamdina]

Can someone tell me if it matters where I mount a thermostat? For example... If i have an engine with the thermostat factory on the top hose, will it work at all if i move it to the bottom for engine conversions sake?

I'm thinkin YES because the cold water from the radiator won't be getting into the engine... but I'm thinkin NO because of the amount of water I'm trying to heat up?

[NA Drifter]

so far, as I know. 4age and Skyline RB25DET have the thermostat at the bottom..

[Frosty]

As long as you put it in the top hose it will work.

[Hamdina]

Thats the whole thing.. i dont really have room

[Hamdina]

115 views and nobody knows?

Is there something different about the design of the coolant system in a 4age to have the thermostat at the bottom?

[jondee86]

As far as I can see, the 4A-GE uses a reduced volume bypass type
system for rapid warmup. When cold, the thermostat is closed. The
pump circulates water thru the engine and past the wax pellet side
of the 'stat, but not thru the radiator.

At about 80 deg C the 'stat begins to open, allowing water to start
to flow thru the radiator. During normal operation the 'stat will open
more or less, to maintain an engine temp of around 90 deg C.

Where the thermostat is located is not particularly important, so long
as you have a partial bypass arrangement. The wax pellet side of the
'stat must be able to taste the temperature of the water circulating
thru the engine while the 'stat is closed.

Hot water rises, and cold water stays at the bottom. If you locate
the 'stat in the bottom hose, and you do not have any circulation, it
will never open and allow water to flow to the radiator. Just make
sure you rig up a bypass hose

Cheers..... jondee86

[Sick Puppy]

This may seem like a silly question to ask, but if you have no circulation, then wouldnt the position of the thermostat be the least of your worries, as your cooling system would be blocked?

[jondee86]

Nup The pump circulates water thru the engine by way of
the bypass hose while the 'stat is closed. There is no circulation
thru the radiator. So what is important is to make sure that the
water circulating thru the motor is flowing over the wax pellet side
of the 'stat.

Then, when the water in the engine has reached operating temp
the 'stat starts to open and allow water to begin circulating thru
the radiator. If the 'stat is located at a low point and in a stagnant
"dead end" part of the pipework, it will take forever to get hot
enough to open. By then the water in the block could be boiling

Exactly the same effect as having a blocked radiator...

Cheers...... jondee86