Sensors TRIAL

Fast Eddie

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In a water cooled engine, does the sensor actually sit in the water and measure water temperature, or is it into a blind hole and measuring the cylinder head metal temperature?
 
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Normally it extends into the water, a solid hunk of copper with the electrics in a hole.
 

Fast Eddie

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Thanks Kommando, so, how do we know that a sensor designed to operate in water is gonna function correctly in air cooled metal?

Water, in direct contact with a sensor, must surely conduct heat differently compared to whatever it’s in contact with in a Norton (either metal or air)?

I’m wondering if this could be a source of some people’s troubles?
 
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Clive

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I’m wondering if this could be a source of some people troubles?
Well Done FE I like it when someone spots the * obvious. Again - a coolant sensor measures the averaged circulating coolant temperature whereas this measures a spot temperature which isn't necessarily wrong. So to return to the question is the actual sensor in contact with a metal surface or what?
 
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If you are referring to the 961 engine ? The temp sensor threads into the back of the head (threaded hole) probe contacts through aluminum threads etc. It is also advised to use a heat transferring compound on the probe . This is stated in the service manual .
 

Fast Eddie

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Hi Tony, yes, we’re are talking about the 961 and the question is:

Is a sensor that’s designed to function in water the right sensor to be using air cooled 961?

More explicitly, is the heat transfer in any way different enough to cause errant readings, or short life expentency or any other issues?
 
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If we could get to look at the Bosch data book for that sensor. It would give good information. My only worry would be if the sensor is exposed to temperatures beyond its design range. BMW air cooled bikes may be doing something similar ?
 
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How are your new bikes running ? Here in the states if you ordered a New 961 it would be a Euro3 with Omex ECU. How are the Euro3 Omex bikes running ? Can anybody share ? Richard Pearce possibly .
 

BLIGHTYBRIT/SF

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How are your new bikes running ? Here in the states if you ordered a New 961 it would be a Euro3 with Omex ECU. How are the Euro3 Omex bikes running ? Can anybody share ? Richard Pearce possibly .
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/360183075288. This is the stuff that’s a must, I use it on dry pocket thermistor s on gas boilers,the sensor head is free from scale or Muck then to give an accurate reading, my 2016 bike is running fine 16,000 miles on start up it ticks over at 1500 revs, warms up & drops to 1250 approx, I’m sure they must be ok for the job,it there is a lack of heat sink compound around the sensor end then that can effect it even if the sensors new
 

Fast Eddie

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How are your new bikes running ? Here in the states if you ordered a New 961 it would be a Euro3 with Omex ECU. How are the Euro3 Omex bikes running ? Can anybody share ? Richard Pearce possibly .
How the new bikes are running is a bit of a mixed bag it seems Tony. Mine, and others, have been flawless, others have reported repeat returns to factory / dealer on new machines.

Thanks to you & Blighty for the conductivity paste reminder though (I’ve got some in the way). Being manually applied could easily lead to discrepancies in production. And if it’s as important to the function as it appears, this should be top of the list for fault finding I’d say.

I still have a nagging doubt about the choice of sensor, but I’m well out of my depth with it, so will just have to hope and assume it’s fit for purpose.
 

Clive

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I still have a nagging doubt about the choice of sensor, but I’m well out of my depth with it, so will just have to hope and assume it’s fit for purpose.
Hmmmm yes the head sensor setup does seem to actually work: what Fast Eddie and I are querying is that the Bosch sensor is designed to have its low thermal mass probe with the functional bits inside surrounded by hot circulating water whereas on the 961 it relies on heat being transferred through the body down to the probe - not quite what it was designed for.
 

BritTwit

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If we could get to look at the Bosch data book for that sensor. It would give good information. My only worry would be if the sensor is exposed to temperatures beyond its design range. BMW air cooled bikes may be doing something similar ?
Tony,
When did BMW switch from the airhead to water pumpers on their R1200 line?
2014, 2015?
I wonder which Bosch sensors the late model EFI airheads used?
 
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Tony,
When did BMW switch from the airhead to water pumpers on their R1200 line?
2014, 2015?
I wonder which Bosch sensors the late model EFI airheads used?
That Sounds about right . The R9T Classic line are all air cooled . This is why I was drawn to them.
 

BritTwit

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One of my ridding buddies has an R1200C Montauk.
I'll ask him if he knows which sensors his Beemer uses.
 

comet

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If we could get to look at the Bosch data book for that sensor. It would give good information. My only worry would be if the sensor is exposed to temperatures beyond its design range.
It's on the Bosch web site - there's a catalogue with the details of all the sensors:

http://uk.bosch-automotive.com/en_G...nsors_1/moresensors_sensors_electrics_parts_1

The spec for 0-280-130-026 says it's for oil/water. There is one with similar specifications for air (0-280-130-039). I'm assuming the probe on the air one is insulated from the metal body and that the oil/water one isn't. The temperature range is the same for each.

The SC ECU instructions for setting the 961 tickover state that the head temperature should be at 120C. The head temp gauge in the SC ECU software only goes up to 120C - I don't know if the actual head temperature is likely to go above that?

Bosch-01.JPG Bosch-02.JPG
 
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I can check my head temperature with a thermocouple and my DVM . Does anybody own a IR handheld thermometer ? I will get back when I have that reading .
 
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How the new bikes are running is a bit of a mixed bag it seems Tony. Mine, and others, have been flawless, others have reported repeat returns to factory / dealer on new machines.

Thanks to you & Blighty for the conductivity paste reminder though (I’ve got some in the way). Being manually applied could easily lead to discrepancies in production. And if it’s as important to the function as it appears, this should be top of the list for fault finding I’d say.

I still have a nagging doubt about the choice of sensor, but I’m well out of my depth with it, so will just have to hope and assume it’s fit for purpose.
Hello FE , Are the new bikes with problems having to go back repeatedly ? I remember that GLB had his SC ECU replaced with a Euro 3 Omex , and I wonder how its going for him ? I know its expensive , but if the Euro 3 OMEX has been sorted and works well this may be the way forward for the SC guys. I would love to hear from all of our Euro 3 OMEX owners.
 

Fast Eddie

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I’m only echoing what owners have reported on here Tony, whereby a few have had gremlin type isssues on new bikes, sometimes we’ve persuaded them that it’s somethimg that will be resolved by a remap and open pipes etc, but some have had repeat attempts to problem solve.

Hence, something like the sensor being on the edge of its design functionality, or inconsistent application of conductivity paste could, I’m thinking, be potential causes.
 

comet

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... or inconsistent application of conductivity paste
I'm not sure what the paste is actually doing in this scenario. I have used it previously to ensure a good interface between two materials, such as a CPU in a computer and the metal heat sink that sits on it. Without the paste there could be a small air gap between the CPU and the heat sink, so the paste ensures that the heat from the CPU can be properly transmitted to the heat sink. This would be a similar application to the boiler thermistor that BlightyBrit refers to above.

I haven't removed the head temp sensor so I don't know what's behind it. If there's a big air gap then I can't see what difference the paste would make. In that case, putting the paste on the threads would make more sense as the sensor is picking up the heat through its body as per Clive's note above. If it's a small "dry pocket" then packing it with the paste would give better heat conductivity.

On the other hand, maybe it just has to work and doesn't need to be that accurate as long as it can register the difference between hot and cold.

Just thinking out loud really...........
 
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The Air gap is not huge . The paste as you've stated ensures a good thermal transfer from head to probe.
 
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