position CLT sensor ?

[Carlos]

Hi,
I am catching up on my old project and want to be on the safe side with the sensors first.
When idling for a few minutes, e.g at the traffic lights stop, the temperataure on the MS gauge goes well above 100°C, whilst my normal gauge in the dash still is at 90°C. Both are calibrated, so no error here.
I assume that the temperature in the manifold simply changes faster (due to thin walls) than the temp of entire engine block, so this should not be unusual.
However the question is where should I place the CLT sensor? Currently I have it mounted in my V8 intake manifold.
Is it this position OK or should I place it in the water hoses to the radiator, or use a pickup thread in the radiator?

Txs for any hint
Carlos

[billr]

Where in the intake manifold; in the coolant passage from head-to-head that has the thermostat and then outlet to radiator? That should be fine. As to why they read different, where is the sensor for the dash gauge located, down on one of the heads? I have to take your word for it that they are "calibrated" okay, but they will never read exactly the same. How about swapping their locations, see if the temp difference follows the sensor or stays with the sensor location.

[Carlos]

Where in the intake manifold; in the coolant passage from head-to-head that has the thermostat and then outlet to radiator? That should be fine.

Yes it is sitting in the passage close to cyl 1.

As to why they read different, where is the sensor for the dash gauge located, down on one of the heads?

Sitting in the left sidewall of the block.

I have to take your word for it that they are "calibrated" okay, but they will never read exactly the same. How about swapping their locations, see if the temp difference follows the sensor or stays with the sensor location.

Saying "calibrated" I mean they are quite linear, showing the same temp, between 80°C and 100°C, what I check with hot water and a reference temp gauge.
Of course there is the parallax error in reading old pointer gauges plus the gauge in the dash is slower than the MS.

I'll see if swapping is feasible i.e. if sensors have the same thread.

Txs

Carlos.

[kaeman]

carlos remember that the water heading back to the radiator will be the hottest water in the engine so the location on the front of the manifold near the thermostat will be warmer than the water in the lower part of the block, because of the water path in the engine.. if you want the gauges to have the same reading you have to mount the sensors in the same location. then they will read the same, but since the cool water from the radiator enters the block then flows up through the heads and out the front of the manifold at the thermostat, the water at the thermostat will always be hotter, than the water entering the block from the radiator, or the radiator is not working. don't worry about the 10 degrees, that is just because of the location of each sensor.

[Carlos]

... don't worry about the 10 degrees, that is just because of the location of each sensor.

This is what I fully understand, the reamining question is, if the temp sensor, being a significant source for control (e.g. warmup), is positioned well at the hottest place.
txs
C.