Cylinder Head Temp - Observation

I fitted a neat little cylinder head temp gauge when I first bought my 'no water temp gauge' Bandit last year.

The Cyl Head temp shows little Temp variation when the Bandit is moving along highways; 80 - 81C Summer, 77 Winter. Even up hills in Summer not much change (83).


I was heading up the highway last week - lovely day about 29 degrees - on a long straight section with a cool and strong sea wind (20 knots) blowing directly across my path from the right. I was very surprised to see the head temp sitting on 75C (not 81) - the coolest I have observed on the cruise.


When I turned off the highway (Left) into the forest heading with the breeze on my back......Temp back to 82C.

So somehow the big 1250 seemed to like the transverse breeze, something I didn't think would make much difference to the temp.


Basic perhaps, but that's interesting!! I thought.


Cheers GG

Got a pic of the set up?
I've often wondered but not overly worried because I don't sit in traffic. 
The B1250 was my first water cooled bike to not have a temp gauge. Then I got the FZ and it didn't have one either. And now my new car doesn't have one as well. That might be well and good while they're all new but we all know coolers lose efficiency over time and I'd rather not have a light come on when it's too late.

Oh and cooler temps across the radiator isn't uncommon.  Slow down the air flow and it carries away more heat.

Ah...yep airflow across the radiator - thanks. I was wondering what it could be, and first time I have seen such a temp drop. The  wind was very strong and cool.

I will take a pic and try to post (if I can collect the 'know-how' - no success posting to date).

When I come to road works on the Bandit and stop, the temp goes high quickly. I let it go to about 100+ and then shut down and wait for the traffic to move.

I have had a few cyl  heads temp gauges on my engines. I had one on my last two L Cruiser utes. I really like them as they tell an honest and immediate story. The L cruiser ones had alarms you can set. My Bike one I just monitor.

Will try to get a pic and details up later today - going out now, alas on 4 wheels!

Thanks GG

Your fan should come on if it gets too hot . I was under the impression that the temperature will go even higher when you turn the motor off at first before it starts to cool off , so turning it off for a short time may not do much ...........I may be wrong
Manual says the fan comes on @ 105 deg & off @ 100 deg so theoretically 100 deg shouldn't be a problem .
 Interesting to see what the temp. does during different circumstances though 

That makes sense.  I've always lost the most coolant, (or moved it to the header tank) with the cars I've had a bit hot, upon stopping the engine.  Best to keep the coolant moving with a fast idle.  

Worthy to consider, that the bigger the difference in temperature, the faster heat will be disposed of by the radiator  My book says 50% for the coolant mixture.

Coolant raises the boiling point of water - the mixture can rise to a higher temperature without boiling with coolant in it.  Less pressure in the system as a result, more effective heat disposal.  People run higher mixtures in MX bikes around here.  While Ethylene Glycol has a much higher boiling point than water, it only has approx half the specific heat of water, so it is not as good at transferring heat as water.  Its main role is in raising the boiling point of the coolant mixture which prevents coolant loss and improving the efficiency of the system as a whole by providing for a higher temperature difference between the inside and outside of your radiator.  50% boils at 107 degrees and has a thermal heat transfer capacity of 3/4 that of plain water.  While pure ethylene glycol boils at 197 degrees, it is not a good thing to use it that way, because of its relatively poor thermal capacity.  The 50/50 recommended mix represents a trade off, between a higher boiling point and thermal conductivity.  So endeth my preoccupation with useless facts for the day.  

Like many here, I'm also concerned about the functioning of my cooling system.  

Modifications I've considered, include putting an LED pilot light in the circuit to the cooling fan, so I can see when it operates.  

The gauge seems like a good idea.  Love to see pics, some details of the installation please.

This thread might unlock the secret to posting pics.

https://nswbandits.forumotion.net/t1283-posting-photos-a-picture-story?highlight=photos

Would need to know more about the installation and sensor...could be as simple as the sensor sitting in the discharge air from the radiator and the crosswind mixing some cool air with the radiator air and lowering the temperature at the sensor that way.

And actually, i found the info regarding the specific heat of water useful...makes sense as pure water has the 2nd highest specific heat of any known substance, next to pure hydrogen, (that would be my useless fact for the day )

Thanks bandits. I did take some pics this afternoon but still coming up the learning curve I am afraid in terms of posting here. I will continue and get them up if I can.

The gauge is a TTO brand. I am sure you have seen then about. Very small is size and neat. Digital display that switches (cycles) between current cyl head temp and max recorded. The max recorded can be reset. When I mounted mine I inadvertently covered the tiny reset hole on the rear of the gauge casing - another job for an idle day. So unintended I have captured the max temp for the past 12 months which is 103 C.

There are a few variations on the sensor washer size (end of wire) with the TTOs. One is a crusher washer that fits under a spark plug, but that doesn't appeal to me so I bought the 10mm dia washer version. 

I fitted the sensor washer under a convenient bolt - although not so convenient to undo/tighten - on the bottom side of the water outlet? (inlet?) on the left, rear side of the engine. There is a top and bottom bolt and the bottom one is easiest to get to I found. The 10mm dia sensor is too large for the water outlet bolt so a put a brass washer of correct dia over the top and it all looks great.
...

Yes, I do usually cut my engine when stuck at sizeable road works when temp goes >100C, just something I do, but have wondered if it is the 'right thing'. For an air-cooled engine a good idea, but probably no need with the Bandit. I may be imagining but the bike seems to be a cooler when I get going again rather then when idling with the huge exhaust etc the whole bike seems to get soaking hot ( my legs too).
...

So I will try the pics business again. I would like to show you the mounting and fittings positions. I highly recommend the TTO as a compact and very useful addition - easy to mount and monitor on the road - for only around $50 I recall.

I also just like to see how the mighty Bandit engine temp changes in differing conditions, traffic, cross-wind, hills, summer/winter etc and for this the TTO is a 'mine' of info.   

Cheers GG

Actually when I was looking for a temp gauge, it was the smaller TTO that seemed to fit the bill.  

Not sure if you can still get the silver units (the TTO web site mainly shows blacks ones and an orange unit)


Different type of sensors can be ordered (the main pipe from the themo housing on the Bandit is 21mm ID)



Unfortunately (for my wallet) I looked further into Trail Tech's web site and got mesmerised by the bling of the bigger setups and ended with the Striker as it had both the temp and battery (and 2 dozen other things as well).




Now including the GPS I have 3 speedo's, and due to changing wheel sizes and front cogs, three different readings, got to get round to recalibrating them one day.  But I did find riding through Victoria was easier when just looking at the one that read too high

keeping in theme with temp gauges,

I bought a JMT oil filled temp gauge that replaces your oil fill cap. http://www.moorespeedracing.co.uk/oil-temperature-gauges/jmt-oil-temperature-gauge.html 

my bike usually sits on 80* but is picking up sump core temperature, not head temp.

I only bought it for my new engine as it has been bored,  and it will be more than likely running hotter. this will give me an indication for if I need a bigger oil cooler.

before this though, after sitting in queensland city traffic in summer, on an air/oil cooled bandit, I could not only feel the heat, but smell the engine, knowing it has been screaming in pain from the heat, but never missed a beat after 9 years, so I don`t think it really needed one, and if your bike does a radiator, your going to feel, see, or smell coolant on a water cooled bike and pull over anyway, so really, why the need?

to each their own I understand this, it just ads, IMO , to much shit on your bike, unless you want it to look like the millennium falcon, and you like gadgets that really don`t do much but shine and whistle.     maybe that's why I`m still living in the past on a 1200.

Yes that's the one Barry; your first photo of the silver TTO.

I mounted mine fwd of, and below the handle bars on a bracket I made that followed the shape of the TTO.

For the water temp gauge deprived Bandits this is a great option - small and simple, and it just shows current temp and max temp.

I also like that it is sensitive and immediate.

Cheers GG

Where I have my sensor attached is probably picking up more of a core temp too. Mines not actually on the head.

The spark plug mount would show higher temp I assume, but I just don't like that fitting.

Personally, so long as you can do it with some accuracy, I'm a fan of measuring the coolant temperature.  

The bottom line is keeping your coolant.  So long as your coolant stays in the motor, all is good.  If your gauge is accurate enough, you can see the point at which you maybe should start paying attention coming, before it actually arrives. 

Most built in "gauges" don't measure for nuts, but do give an indication, particularly where the coolant is on its way out and the temperature is on the rise, by then it's a bit too late.  That's where actual numerical accuracy can be useful ahead of that point.   

I agree with busying up the front of motorbikes with all sorts of do-dads, which probably could have been integrated in the first place, however, these are Bandits.  No frills, bang for buck motorcycling at its best, the beauty of which you can have what you want, but most of us add something, then something else, and another etc. until it starts to get a bit stupid and we all think why didn't we think about all of this in the first place and get something with integrated functions, or at least get together a decent mount for what is now spread across both sides of the bars, the centre clamp and we keep eyeing off that bit of fairing there, or maybe the inside of the screen.  

Still, it's nice to have a few things, and I'd rather add them to a bike like a Bandit than have all sorts of other stuff that I really think has no place on a motorbike in the first place, because the market is all about the features.