Engine Running Temperature.

[Billypownall]

Generally pleased with our new boat and minor snags are being ironed out as they should be. One question though to you experts whose wisdom I really do respect. What temperature should the engine be running at ? It seems to me to be running rarther cold at less than 70 C . It has been out only with a very cold ambient temperature so far but that surely should make no difference to the running temperature if this is thermostatically controlled. I would have expected the engine to run nearer 80C but does it matter?

[Maverick]

Generally pleased with our new boat and minor snags are being ironed out as they should be. One question though to you experts whose wisdom I really do respect. What temperature should the engine be running at ? It seems to me to be running rarther cold at less than 70 C . It has been out only with a very cold ambient temperature so far but that surely should make no difference to the running temperature if this is thermostatically controlled. I would have expected the engine to run nearer 80C but does it matter?

 

Might help if you mention what type the engine is so folk with a similar engine can advise you.

[RobinJ]

Might help if you mention what type the engine is so folk with a similar engine can advise you.

Might also help if you said how far, how fast, how long?

[Billypownall]

Might help if you mention what type the engine is so folk with a similar engine can advise you.

Might also help if you said how far, how fast, how long?

Good points you two. Engine is a Barrus Shire 40 h.p. The temperature rises relatively quickly to about 65 to 70C then remains the same.

[Lol]

Good points you two. Engine is a Barrus Shire 40 h.p. The temperature rises relatively quickly to about 65 to 70C then remains the same.

 

Billy

 

this will not help with your engine (so not sure why I am replying.....) but we have a Beta 38 that sounds about the same as yours temperature wise and I did question Beta about it and they say this is OK

 

it feeds the calorifier first and during this stage is at about 65degC, then once this is up to temp the skin tank comes into play and the whole thing seems to top out at an indicated 70degC regardles of ambients or running time

 

I say indicated because I wouldnt think the instrument is terribly accurate, I may test it this summer out of curiosity ?

[bottle]

From Barrus Shire (PDF) owners manual.

 

·

The temperature of coolant flowing to the calorifier from the engine can be between 85

– 90°C. A blender valve must be incorporated in the calorifier/hot water system outlet to

lower the hot water temperature for domestic use.

 

So it does look as though the engine is running 'cold'.

 

Reasons:

 

Wrong thermostat fitted

 

Thermostat stuck 'open'

 

Thermostat not fitted

 

Temperature gauge faulty.

[Tony Brooks]

From Barrus Shire (PDF) owners manual.

 

·

 

So it does look as though the engine is running 'cold'.

 

Reasons:

 

Wrong thermostat fitted

 

Thermostat stuck 'open'

 

Thermostat not fitted

 

Temperature gauge faulty.

 

Except some marinisers deliberately fit a 60 to 70 degree thermostat if they think a calorifier might be going to be used. That way they limit maximum hot water temperature.

 

Its the Thermostat that controls the running temperature. so forget about the skin tank etc. M<y guess is that its deliberately running at that temperature.

[PeterF]

Generally pleased with our new boat and minor snags are being ironed out as they should be. One question though to you experts whose wisdom I really do respect. What temperature should the engine be running at ? It seems to me to be running rarther cold at less than 70 C . It has been out only with a very cold ambient temperature so far but that surely should make no difference to the running temperature if this is thermostatically controlled. I would have expected the engine to run nearer 80C but does it matter?

I think Barrus normally fit twin thermostats, a 70°C one and an 80°C one. At first both are closed and the engine warms up to 70°C or so. Once at that temp the first one opens and heats the calorifier. As the Calorifier warms up the second one opens and sends hot water to the skin tank.

 

If you do not run your engine for long enough it will settle at around 70°C while it warms the calorifier.

 

If you do not have a calorfier coil off the engine the builders may well remove one of the thermostats as the second one may not get water flow over it if there is no flow out of the intermediate chamber. The easiest one to remove is the second one as the first one needs to complete thermstat block removing so this would leave you with a 70°C thermostat controlling the main cooling.

 

Not sure if this is exaclty right for your problem but may be a pointer.

 

See the Shire brochure Page 12 for an explanation of their twin thermostat system.

 

Shire Brochure - see page 12 for thermostat details

 

I found this out because I fitted a twin coil calorifier instead of a single coil and when I conected to the engine it would not work, the flow still went straight to the skin tank because the one thermnostat had been removed.

 

PeterF

[steelaway]

Except some marinisers deliberately fit a 60 to 70 degree thermostat if they think a calorifier might be going to be used. That way they limit maximum hot water temperature.

 

Its the Thermostat that controls the running temperature. so forget about the skin tank etc. M<y guess is that its deliberately running at that temperature.

 

 

Hi

 

I have a Barrus 45 and is exactly the same in regard to temp readings - from new.

Mine hardly ever reaches more than 70 degrees and it can drop. Its as though the cooling through the calorifier is enough.

I can't believe that this is sufficient to keep the engine cool - no matter how many hours I run it.

Plus it should never drop as the stat should maintain the engine temp at 70 degrees.

I have checked my keel stat and it is at 85degree but it must remain closed.

Any thoughts?

 

Alex

[Billypownall]

I think Barrus normally fit twin thermostats, a 70°C one and an 80°C one. At first both are closed and the engine warms up to 70°C or so. Once at that temp the first one opens and heats the calorifier. As the Calorifier warms up the second one opens and sends hot water to the skin tank.

 

If you do not run your engine for long enough it will settle at around 70°C while it warms the calorifier.

 

If you do not have a calorfier coil off the engine the builders may well remove one of the thermostats as the second one may not get water flow over it if there is no flow out of the intermediate chamber. The easiest one to remove is the second one as the first one needs to complete thermstat block removing so this would leave you with a 70°C thermostat controlling the main cooling.

 

Not sure if this is exaclty right for your problem but may be a pointer.

 

See the Shire brochure Page 12 for an explanation of their twin thermostat system.

 

Shire Brochure - see page 12 for thermostat details

 

I found this out because I fitted a twin coil calorifier instead of a single coil and when I conected to the engine it would not work, the flow still went straight to the skin tank because the one thermnostat had been removed.

 

PeterF

Thank you all for the replies particularly PeterF . The Shire Brochure seems clear enough and suggests that the skin tank thermostat should open at 81C which seems about right to me. This thermostat must be incorrectly set as the engine temporature will not top 70C. We have certainly run the engine for several hours,enough to heat the calorifier to its maximum of 71C. Actually Barrus make a point of quick engine warming saving wear and tear but surely if the engine never reaches a reasonable temperature there will be more wear or as I questioned before does it matter ?

[chris w]

Have you checked the calibration of the temperature gauge? It might only be accurate to say +/-10% which would account for most of the difference you are seeing.

 

Chris

[Lol]

Have you checked the calibration of the temperature gauge? It might only be accurate to say +/-10% which would account for most of the difference you are seeing.

 

Chris

 

it feeds the calorifier first and during this stage is at about 65degC, then once this is up to temp the skin tank comes into play and the whole thing seems to top out at an indicated 70degC regardles of ambients or running time

 

I say indicated because I wouldnt think the instrument is terribly accurate, I may test it this summer out of curiosity

 

You really must pay more attention Chris, i think maybe I was being a little too nuanced, one of the things I have been accused of...

 

your post is much clearer than mine, what I was implying is that my temperature gauge is not particularly precise (probably only 5degC readable) and probably not so accurate also, and that maybe the OP (I learned what one of these is recently) has a similar one

 

Billy - maybe you can check it against something you know is accurate?

[Billypownall]

You really must pay more attention Chris, i think maybe I was being a little too nuanced, one of the things I have been accused of...

 

your post is much clearer than mine, what I was implying is that my temperature gauge is not particularly precise (probably only 5degC readable) and probably not so accurate also, and that maybe the OP (I learned what one of these is recently) has a similar one

 

Billy - maybe you can check it against something you know is accurate?

I am not sure how to go about checking the temperature gauge. I must say that if the engine is in fact running at 80c ,as it apparantly should be,a temperature gauge reading under 70c must be 15% incorrect. That is not good enough. There seems little point in fitting such an incorrect instrument. Presumably the coolant would be boiling when the gauge reads only about 85c . I actully think the engine is not running hot enough and I look forward to some imput from the agents in due course.

[blackrose]

I am not sure how to go about checking the temperature gauge. I must say that if the engine is in fact running at 80c ,as it apparantly should be,a temperature gauge reading under 70c must be 15% incorrect. That is not good enough. There seems little point in fitting such an incorrect instrument. Presumably the coolant would be boiling when the gauge reads only about 85c . I actully think the engine is not running hot enough and I look forward to some imput from the agents in due course.

 

What actually is the problem of an engine that runs cool? I would have thought in the hot summer months this would be a good thing? In summer my Izusu 55 runs at around 90 deg which worries me that it doesn't leave much room until it overheats were the engine to be pushing the boat against current for example.

Edited April 1, 2008 by blackrose

[Lol]

I am not sure how to go about checking the temperature gauge. I must say that if the engine is in fact running at 80c ,as it apparantly should be,a temperature gauge reading under 70c must be 15% incorrect. That is not good enough. There seems little point in fitting such an incorrect instrument. Presumably the coolant would be boiling when the gauge reads only about 85c . I actully think the engine is not running hot enough and I look forward to some imput from the agents in due course.

 

 

there are two things at play here:

 

precision, how well can you actually see the needle against the scale, angle of view, size of instrument, units of scale all effect

 

accuracy, once you have read just how close is your reading to the real thing

 

if you have errors in both of these (which on my 50mm diameter, thick needled, coarse scaled temperature gauge I think I have) it can be significant

 

There are several ways to calibrate instruments (or more importantly instrument/sensor combinations) but in this situation the easiest and most reliable way to check would be to actually measure the temperature of the flow as close to the actual engine sensor with an independant and accurate instrument

 

if you can do this you may be lucky and be able to adjust your gauge, if not you will have to mentally apply the adjustment every time you read it

 

this is a welcome break from work, as i type this I am on an oil rig ~100 miles off the shore of Rio de Janeiro Brazil commissioning the mother of all water purifiers and one task amongst others is calibrating hundreds of instruments (including temperature ones)

[RobinJ]

What actually is the problem of an engine that runs cool? I would have thought in the hot summer months this would be a good thing? In summer my Izusu 55 runs at around 90 deg which worries me that it doesn't leave much room until it overheats were the engine to be pushing the boat against current for example.

It probably depends on the engine design.

In theory the cooler the air taken in and the hotter it burns, the more efficient it is, but this is complicated by the fact that we are looking at coolant trmperature. This is because the efficiency of combustion is one thing and the efficiency of cooling another, the less heat wasted the better!

Carbon footprints - global warming

[chris w]

as i type this I am on an oil rig ~100 miles off the shore of Rio de Janeiro Brazil commissioning the mother of all water purifiers.................

 

Do you use Milton's Fluid for this? If so you can help with another thread at the moment

 

Chris

 

I am not sure how to go about checking the temperature gauge. I must say that if the engine is in fact running at 80c ,as it apparantly should be,a temperature gauge reading under 70c must be 15% incorrect. That is not good enough. There seems little point in fitting such an incorrect instrument. Presumably the coolant would be boiling when the gauge reads only about 85c . I actully think the engine is not running hot enough and I look forward to some imput from the agents in due course.

 

Well the speedo in a car only has to be accurate to +/-10%. If this is the case for your temperature gauge too, then a true reading of say 75degC will be indicated as somewhere in the range 68C to 82C.

 

Chris

[Yoda]

For those who wish to calibrate their temperature indicators, the following might be useful.

 

Remove the indicator and its sensor from the installed boat and connect to a fully charged battery, if required.

 

Immerse sensor into a container of cold water. With an NPL thermometer, immerse and gently stir the water so that the fluid is all the same temperature. Take a reading of the temperature after two minutes immersion. Record both indicator and thermometer.

 

Pour boiling water into the cold water sufficient to raise the temperature to between 40 and 60 degrees Celcius. Repeat as above.

 

Pour out the contents and replace with boiling water and stir thoughly. Record temps as above.

 

This is a three point check that should give enough information to accept or reject the sensor or indicator.

 

The boiling point of water is 100.3 degrees Celcius.

Edited April 1, 2008 by Yoda

[Lol]

Do you use Milton's Fluid for this? If so you can help with another thread at the moment

 

Chris

 

 

 

Well the speedo in a car only has to be accurate to +/-10%. If this is the case for your temperature gauge too, then a true reading of say 75degC will be indicated as somewhere in the range 68C to 82C.

 

Chris

 

Chris

 

if you mean threads about sterilising tanks yes i can help sterilising is a core part of what we do, have to say though i am a bit sick of answering these, if the OP searches he will find the gems

 

as for using milton fuid out here we would need a tanker, this machine has a footprint about the size of half a fotball pitch and is almost as high as is long, it produces nearly 2000 cubic meters of water per hour, thats over 500 litres per second

Edited April 1, 2008 by Lol

[Machpoint005]

The boiling point of water is 100.3 degrees Celcius.

Procedure seems fine, Yoda, but does your instrument panel engine temperature gauge really read to 0.3 of a degree? That's some big dial...

 

Ian

[Lol]

For those who wish to calibrate their temperature indicators, the following might be useful.

 

Remove the indicator and its sensor from the installed boat and connect to a fully charged battery, if required.

 

Immerse sensor into a container of cold water. With an NPL thermometer, immerse and gently stir the water so that the fluid is all the same temperature. Take a reading of the temperature after two minutes immersion. Record both indicator and thermometer.

 

Pour boiling water into the cold water sufficient to raise the temperature to between 40 and 60 degrees Celcius. Repeat as above.

 

Pour out the contents and replace with boiling water and stir thoughly. Record temps as above.

 

This is a three point check that should give enough information to accept or reject the sensor or indicator.

 

The boiling point of water is 100.3 degrees Celcius.

 

quite correct, but not sure where most normal boaters would get an NPL thermometer

[Dylan]

quite correct, but not sure where most normal boaters would get an NPL thermometer

There are no NPL thermometers listed on Ebay, therefore I refuse to believe that they exist

[Machpoint005]

There are no NPL thermometers listed on Ebay, therefore I refuse to believe that they exist

Ha! Go to www.npl.co.uk for calibration details...

[Dylan]

Ha! Go to www.npl.co.uk for calibration details...

[bargeeboy]

The Barrus engineer is at Narrowcraft next week.

 

We make a point of the factory man checking each new boat to ensure the installation is to Barrus's exacting standard.

 

He will check tick over speed, emmissions, temperature, charging, etc. etc.

 

This makes any potential warranty claims a mere formality as they will not fob us off with 'it must be the installation'.

 

The lower temperature on the calorifier is set so as not to scald yourself with the hot water.