Beta 38 coolant temp.

[Bro]

I have a beta 38 engine and the Manual says it should run at 80 deg C. but I've never seen it above 70 deg C. Running engines cooler than optimum may cause problems in the long term, I think, so e-mailed Beta Marine for comment. No reply! (Could 'phone but would prefer written response doncha know.)

 

I'm loathe to replace the thermostat with higher temp. one because it may invalidate the engine warranty.

 

If anyone out there has same engine I'd be pleased to know what temp yours run at?

 

In general, what views are there on running engines at lower temperatures? Good idea, bad idea, doesn't matter?

[churchward]

I have a beta 38 engine and the Manual says it should run at 80 deg C. but I've never seen it above 70 deg C. Running engines cooler than optimum may cause problems in the long term, I think, so e-mailed Beta Marine for comment. No reply! (Could 'phone but would prefer written response doncha know.)

 

I'm loathe to replace the thermostat with higher temp. one because it may invalidate the engine warranty.

 

If anyone out there has same engine I'd be pleased to know what temp yours run at?

 

In general, what views are there on running engines at lower temperatures? Good idea, bad idea, doesn't matter?

How are you measuring it? Is it just on of the auto dials they are not always that accurate. Possibly a daft question but have you checked that there is a thermostat in the engine?

 

anyway, I do have a Beta engine like yours but I have never measured the temp so can't answer as to what temp it runs at.

[Bro]

How are you measuring it? Is it just on of the auto dials they are not always that accurate. Possibly a daft question but have you checked that there is a thermostat in the engine?

 

anyway, I do have a Beta engine like yours but I have never measured the temp so can't answer as to what temp it runs at.

 

 

I asked Beta about accuracy of their instruments but as I say ; no reply! Engine new so 'stat must be in place(?).

[alan_fincher]

The accuracy of automotive type instruments probably isn't very great.

 

If concerned, you could consider measuring with a separate device, such as an infrared thermometer, (although they are typically not that accurate either).

 

Also the opening temperatures of typical thermostats is pretty imprecise to.

 

It's possible (say) that the actual temperature is 75 degrees, (meter reading low, thermostat opening slightly early).

 

Just because it's sold as a new engine, I would not discount the possibility that a faulty 'stat has been fitted, (or even that someone got distracted, and left it out!).

 

Edit:

 

One consequence if it really is running cool, assuming you have a calorifier, is that your domestic water will also not be heated as hot.

 

With some engines there is sometimes a deliberate policy to fit a cooler 'stat than is used in automotive or industrial use, to stop calorifier water becoming scalding hot, (although a mixer valve on the take off is a better solution). Is there any possibility your engine has been so modified ? Is any of the paint disturbed ?

Edited July 22, 2009 by alan_fincher

[Ray]

I've had an ongoing problem with the hot water in the calorifier not staying warm overnight. After lots of experiments/investigations, someone suggested the water in engine might not be getting warm enough to heat the domestic hot water sufficiently so that the temperature didn't drop so much overnight.

 

I measured the coolant temperature last weekend after a 3 hour trip and found it was 70.5C. I mailed Beta along the same lines as the OP and got a reasonably fast response. They say that the engine isn't being stretched so it is running cooler and the thermostat is acting as it should and just opening at around 70C and would be fully open at 80C.

 

As I don't anticipate any river cruising - which is what I presume stretches the engine, I did enquire whether I could get a diferent thermostat but, again like the OP, haven't had a reply yet.

 

Judging by Beta's limited response, they seem more worried about the engine running too warm than about it running too cool.

 

Would be interested to learn what Beta say if anyone calls them on the phone with a similar query.

 

Anyone know how precise thermostats are and whether even replacing like for like might give me a few more degrees to play with or whether I could get one that started to open at around 75C instead of 70C, given that a 10C range between starting to open and being fully open would still bring it within the normal engine temperature range?

 

Ray

[WotEver]

I've had an ongoing problem with the hot water in the calorifier not staying warm overnight. After lots of experiments/investigations, someone suggested the water in engine might not be getting warm enough to heat the domestic hot water sufficiently so that the temperature didn't drop so much overnight.

 

I measured the coolant temperature last weekend after a 3 hour trip and found it was 70.5C. I mailed Beta along the same lines as the OP and got a reasonably fast response. They say that the engine isn't being stretched so it is running cooler and the thermostat is acting as it should and just opening at around 70C and would be fully open at 80C.

 

As I don't anticipate any river cruising - which is what I presume stretches the engine, I did enquire whether I could get a diferent thermostat but, again like the OP, haven't had a reply yet.

 

Judging by Beta's limited response, they seem more worried about the engine running too warm than about it running too cool.

 

Would be interested to learn what Beta say if anyone calls them on the phone with a similar query.

 

Anyone know how precise thermostats are and whether even replacing like for like might give me a few more degrees to play with or whether I could get one that started to open at around 75C instead of 70C, given that a 10C range between starting to open and being fully open would still bring it within the normal engine temperature range?

 

Ray

 

Hi Ray,

 

If you want to test your own thermostat it's quite easy to do. Put it in a saucepan full of warm water with a cooking thermometer in it. Slowly raise the temperature with the gas ring and note at what temperature the stat starts to open.

 

Cheers,

Tony

[wrigglefingers]

My Beta 43 runs at 68 degC according to the 'stat. I worried and worried about this until I realised that a discharge radiator was placed between the engine and 'stat in the circuit. She probably does run slightly under temperature on the cut but not by much, and I've had no problems with either the engine or the hot water from the calorifier (touches head for luck) so I don't worry anymore.

[Ray]

. . . I've had no problems with either the engine or the hot water from the calorifier (touches head for luck) so I don't worry anymore.

 

What size calorifier have you got and does the domestic water stay hot enough overnight for a shower the following day?

 

Have you added any additional insulation around the calorifier?

 

Ray

[alan_fincher]

<Snip>

They say that the engine isn't being stretched so it is running cooler and the thermostat is acting as it should and just opening at around 70C and would be fully open at 80C.

<Snip>

 

<Snip>

Anyone know how precise thermostats are and whether even replacing like for like might give me a few more degrees to play with or whether I could get one that started to open at around 75C instead of 70C, given that a 10C range between starting to open and being fully open would still bring it within the normal engine temperature range?

<Snip>

 

I find Beta's response out of line with my experience of BMC stats, both in boats, and (yaers ago) in cars.

 

I can't see why a stat in a Beta engine should behave differently from one in a BMC.

 

I've tested a number in water, with a thermometer over the years, and they generally open very little until the water is heated to the quoted temperature, and then open pretty smartly after that.

 

I've changed a 74 degree stat on a BMC for an 82 degree one. Tested out of the engine, both opened at about the point they should, and when fitted, allowing for gauge inaccuracies, the temperature is much as I would expect.

 

If you have a genuine 80 degree stat, I'd certainly expect the temperature to keep rising until it got close to that. Unless it's an inaccurate gauge and/or a dodgy stat, I'd expect to get more than 70 on the dial.

 

Perhaps there is something about beta engines I don't know. These are definitely a design with just the one stat, aren't they ?

[Bro]

I've had an ongoing problem with the hot water in the calorifier not staying warm overnight. After lots of experiments/investigations, someone suggested the water in engine might not be getting warm enough to heat the domestic hot water sufficiently so that the temperature didn't drop so much overnight.

 

Try putting a non-return valve in the coolant hose between engine and calorifier (prevents back flow of hot water to cooling engine). I had same problem and it worked for me. Now have roasty toasty shower in the mornings (provided don't run off all hot water night before of course).

[NB Willawaw]

Assuming that the gauge is correct, the main issue is that you may use a bit more fuel at the lower temp and the engine wont run as lean as desired but 70 degrees C is still very acceptable and I suggest that you dont worry about it.

[Ray]

Try putting a non-return valve in the coolant hose between engine and calorifier (prevents back flow of hot water to cooling engine). I had same problem and it worked for me. Now have roasty toasty shower in the mornings (provided don't run off all hot water night before of course).

 

Thanks for the suggestion

 

I've tried most things, including NRVs. The conclusion is that it is the engine not heating the water above 70C and even a 2C temperature drop every hour over 12 hours lowers the temperature to 46C which is too cool for a shower. Now if the engine heated the water to 80C the morning temperature would be 56C, much warmer!

 

2C may be a lot, but I estimate that is the compound effect of having used some of the hot water the night before for washing up.

 

Beta (and the calorifier supplier) suggest adding more insulation to keep the temperature up.

 

Edited to remove unintentional double post of same content.

Edited July 25, 2009 by Ray

[Bro]

Thanks for the suggestion

 

I've tried most things, including NRVs. The conclusion is that it is the engine not heating the water above 70C and even a 2C temperature drop every hour over 12 hours lowers the temperature to 46C which is too cool for a shower. Now if the engine heated the water to 80C the morning temperature would be 56C, much warmer!

 

2C may be a lot, but I estimate that is the compound effect of having used some of the hot water the night before for washing up.

 

Beta (and the calorifier supplier) suggest adding more insulation to keep the temperature up.

 

Edited to remove unintentional double post of same content.

 

 

I'm trying to establish with Beta whether the calorifier connections on the engine are located one before and the other after the engine 'stat. If they are then the calorifier circuit will be in parallel with the 'stat thus effectively by-passing it. If heat loss from the calorifier circuit is sufficient it would then be possible the engine might never achieve designed working temp.

 

Incidentally, when I earlier said Beta Manual gives 80 C as normal engine temp. I was wrong it is in fact 85 C. An engine at 70 C is thus approx 20% below optimum. Can't be good can it?

 

I await response from Beta.

[NB Willawaw]

I have a source in Beta and my earlier post was his opinion on your question

Edited July 26, 2009 by NB Willawaw

[nb Innisfree]

I'm trying to establish with Beta whether the calorifier connections on the engine are located one before and the other after the engine 'stat. If they are then the calorifier circuit will be in parallel with the 'stat thus effectively by-passing it. If heat loss from the calorifier circuit is sufficient it would then be possible the engine might never achieve designed working temp.

 

Incidentally, when I earlier said Beta Manual gives 80 C as normal engine temp. I was wrong it is in fact 85 C. An engine at 70 C is thus approx 20% below optimum. Can't be good can it?

 

I await response from Beta.

 

Calorifier output should leave before t/stat and return to bottom hose creating a closed circuit when t/stat is closed, as you say if it is in parallel, engine (and cal) will take ages to reach operating temp.

[bottle]

Ray.

 

Do remember that, in a domestic situation, the water is not heated above 60°C and a shower temperature is usually at a lot less than 46°C, nearer 20/25°C at delivery, when thermostatically controlled.

 

If your calorifier was at 46°C then it would still be too hot, if not mixed with cold.

[alan_fincher]

I'm trying to establish with Beta whether the calorifier connections on the engine are located one before and the other after the engine 'stat. If they are then the calorifier circuit will be in parallel with the 'stat thus effectively by-passing it. If heat loss from the calorifier circuit is sufficient it would then be possible the engine might never achieve designed working temp.

 

Calorifier output should leave before t/stat and return to bottom hose creating a closed circuit when t/stat is closed, as you say if it is in parallel, engine (and cal) will take ages to reach operating temp.

 

I'm struggling to get my brain around this a bit.

 

Isn't the "usual" way of doing a calorifier to take hot water from the engine before the thermostat, and to return it to the "bottom hose" ?

 

I would have thought the calorifier circuit usually bypasses the thermostat - that is why another thread on here recently was debating whether the slower warm up of the engine this could result in was damaging to it.

 

I would say such an arrangement always slows the rate at which engine temperature will rise, but doubt that a narrow boat sized calorifier can continue to sap enough heat that a normal engine will not heat up to thermostat temperature, and need to dump more through the skin tank.

 

I've not got the same engine - mine is an old BMC, but the temperatures involved are similar, as it is now fitted with an 82 degree stat. The calrofier bypasses the stat, and starts to heat as soon as the engine produces any heat at all. But in normal operation, (say after 15 minutes), the engine will still be up to thermostat temp, and the stat open, and start to put heat into the skin tank too. The dial then stays pretty damn consistently on just over 80 degrees, whether ticking over in a lock, or belting down the Thames.

 

No way would my calorifier hold the temperature artificially low all the time, although it is no doubt delaying slightly the time the engine takes to reach stat temperature.

[nb Innisfree]

I'm struggling to get my brain around this a bit.

 

Isn't the "usual" way of doing a calorifier to take hot water from the engine before the thermostat, and to return it to the "bottom hose" ?

 

I would have thought the calorifier circuit usually bypasses the thermostat - that is why another thread on here recently was debating whether the slower warm up of the engine this could result in was damaging to it.

 

I would say such an arrangement always slows the rate at which engine temperature will rise, but doubt that a narrow boat sized calorifier can continue to sap enough heat that a normal engine will not heat up to thermostat temperature, and need to dump more through the skin tank.

 

I've not got the same engine - mine is an old BMC, but the temperatures involved are similar, as it is now fitted with an 82 degree stat. The calrofier bypasses the stat, and starts to heat as soon as the engine produces any heat at all. But in normal operation, (say after 15 minutes), the engine will still be up to thermostat temp, and the stat open, and start to put heat into the skin tank too. The dial then stays pretty damn consistently on just over 80 degrees, whether ticking over in a lock, or belting down the Thames.

 

No way would my calorifier hold the temperature artificially low all the time, although it is no doubt delaying slightly the time the engine takes to reach stat temperature.

 

By saying t/stat bypass, I and Bro I think mean t/stat in effect is in parallel as in a bypass going round a town (t/stat) which is incorrect and as you say the correct way is for takeoff to tee off before t/stat which strictly speaking is not bypassing t/stat. Clear as mud probably

[Ray]

Ray.

 

Do remember that, in a domestic situation, the water is not heated above 60°C and a shower temperature is usually at a lot less than 46°C, nearer 20/25°C at delivery, when thermostatically controlled.

 

If your calorifier was at 46°C then it would still be too hot, if not mixed with cold.

 

Keith

 

The water is more than hot enough at night and we can keep it that way in the morning if we don't use any (and I mean any) at night. Otherwise, by morning, the temperature is down arund the 30C mark.

 

The calorifier supplier is saying that the engine doesn't get hot enough during the day to make the hot water really hot, which will compensate for the losses during the night. i.e. If it gets to 85C at night and drops 2C per hour overnight, 12 hours later it is still around 60C. If it only gets to 70C at night, with the same drop, it is down to 45C in the morning. If we've creamed some of the water off at night for washing, that will have lowered the start temperature even further, which is what looks like is happening.

 

I'm going to ty fitting a jacket around the cylinder and see what diffeence that makes.

 

Ray

[bottle]

Ray

 

I think the only solution is what you are going to do, more insulation.

[Naughty Cal]

Our big volvo diesel is supposed to run at a temperature of 80 degrees. Pottering around on the fossdyke it rarely reaches 60 degrees. We still get plenty of hot water but the engine isnt running at its optimum temperature. Take it out onto the Trent or the Ouse and it quickly gets to a steady temperature of 80 degrees.

[n.b.Goldie]

I have a beta 38 engine and the Manual says it should run at 80 deg C. but I've never seen it above 70 deg C. Running engines cooler than optimum may cause problems in the long term, I think, so e-mailed Beta Marine for comment. No reply! (Could 'phone but would prefer written response doncha know.)

 

I'm loathe to replace the thermostat with higher temp. one because it may invalidate the engine warranty.

 

If anyone out there has same engine I'd be pleased to know what temp yours run at?

 

In general, what views are there on running engines at lower temperatures? Good idea, bad idea, doesn't matter?

I put a new beta 38engine in my previous boat. It too ran at an indicated 70 deg. I spoke to Beta who said that 70 is ok but to get back to them if it runs under 70 as it could indicate a faulty thermostat. Had the engine in the boat for some 5 years before I sold it and the motor never missed a beat. Did'nt see any indication of water contamination of the oil at oil changes. Most boats on the cut experiencing cooling issues seem to suffer with over-heating so I would'nt worry too much.

 

best wishes

Ditchdabbler

 

edited to correct spallingg...

Edited July 27, 2009 by ditchdabbler

[Bro]

I'm struggling to get my brain around this a bit.

 

Isn't the "usual" way of doing a calorifier to take hot water from the engine before the thermostat, and to return it to the "bottom hose" ?

 

I would have thought the calorifier circuit usually bypasses the thermostat - that is why another thread on here recently was debating whether the slower warm up of the engine this could result in was damaging to it.

 

I would say such an arrangement always slows the rate at which engine temperature will rise, but doubt that a narrow boat sized calorifier can continue to sap enough heat that a normal engine will not heat up to thermostat temperature, and need to dump more through the skin tank.

 

I've not got the same engine - mine is an old BMC, but the temperatures involved are similar, as it is now fitted with an 82 degree stat. The calrofier bypasses the stat, and starts to heat as soon as the engine produces any heat at all. But in normal operation, (say after 15 minutes), the engine will still be up to thermostat temp, and the stat open, and start to put heat into the skin tank too. The dial then stays pretty damn consistently on just over 80 degrees, whether ticking over in a lock, or belting down the Thames.

 

No way would my calorifier hold the temperature artificially low all the time, although it is no doubt delaying slightly the time the engine takes to reach stat temperature.

 

I think. If the calorifier circuit does by-pass the 'stat then surely the 'stat becomes redundant and ineffective such that the engine will take longer to reach working temp. This begs the question why fit a 'stat at all?

 

Plainly, where there is nothing but a calorifier in the circuit then the time taken to achieve working temp will depend on calorifier capacity. However, in my case the calorifier circuit includes a towel radiator in the bathroom and perhaps the heat dissapated there is sufficient to prevent the engine coolant ever establishing working temp. (remember, the engine 'stat even if fitted, is ineffective).

 

I suspect not just mine but many other installations have a radiator in the calorifier circuit and such installations may not achieve proper engine coolant temperatures.

 

Shall be pleased to hear views from others.

 

I have a source in Beta and my earlier post was his opinion on your question

 

Thanks Mark. Not to worry may well be the Beta Marine view but I'm still not happy to run an engine at a temp. 20% lower than design optimum. Surely, it will be at least inefficient and at worst damaging in the long term.

Edited July 27, 2009 by Bro

[nb Innisfree]

I think. If the calorifier circuit does by-pass the 'stat then surely the 'stat becomes redundant and ineffective such that the engine will take longer to reach working temp. This begs the question why fit a 'stat at all?

 

Plainly, where there is nothing but a calorifier in the circuit then the time taken to achieve working temp will depend on calorifier capacity. However, in my case the calorifier circuit includes a towel radiator in the bathroom and perhaps the heat dissapated there is sufficient to prevent the engine coolant ever establishing working temp. (remember, the engine 'stat even if fitted, is ineffective).

 

I suspect not just mine but many other installations have a radiator in the calorifier circuit and such installations may not achieve proper engine coolant temperatures.

 

Shall be pleased to hear views from others.

 

 

 

Thanks Mark. Not to worry may well be the Beta Marine view but I'm still not happy to run an engine at a temp. 20% lower than design optimum. Surely, it will be at least inneficient and at worst damaging in the long term.

 

As I understand your coolant prob exits before t/stat and then enters cal + rads before returning to skin tank (parallel to t/stat) in this case engine will run cool. Our cal takeoff exits before t/stat and goes to CH/cal circuit before returning to engine and, in summer, feeds one rad + 2 x 50lt cals, in winter 6 rads + 2 x 50lt cals. Engine runs at 80c with quick warmup in summer but in winter needs preheating with diesel boiler and then maintains 80c, or I can divert coolant away from CH untill engine is at 80c. This will then drop to approx 65c when I switch to CH but soon regains 80c (approx 15min to 30 mins depending on engine load)

 

In my case t/stat will stay closed untill engine coolant, + CH if switched through, reaches operating temp (or should do!)

Edited July 27, 2009 by nb Innisfree

[n.b.Goldie]

I think. If the calorifier circuit does by-pass the 'stat then surely the 'stat becomes redundant and ineffective such that the engine will take longer to reach working temp. This begs the question why fit a 'stat at all?

 

Plainly, where there is nothing but a calorifier in the circuit then the time taken to achieve working temp will depend on calorifier capacity. However, in my case the calorifier circuit includes a towel radiator in the bathroom and perhaps the heat dissapated there is sufficient to prevent the engine coolant ever establishing working temp. (remember, the engine 'stat even if fitted, is ineffective).

 

I suspect not just mine but many other installations have a radiator in the calorifier circuit and such installations may not achieve proper engine coolant temperatures.

 

Shall be pleased to hear views from others.

 

 

 

Thanks Mark. Not to worry may well be the Beta Marine view but I'm still not happy to run an engine at a temp. 20% lower than design optimum. Surely, it will be at least inefficient and at worst damaging in the long term.

 

 

Radiators, including towel radiators, should be fitted with a control valve. if you turn them off and the motor's running temp does not rise then (once the calorifier is up to temp) they are not the problem.

 

Conversly, disconnect your skin tank (or turn it off if you have isolator valves) and cool the engine via the radiators only and see how long (once the calorifier is up to temp) it takes before the motor begins over-heat, I think you will find it over-heats quite quickly as a single radiator and a towel radiator are not likely to dissipate more than a couple of KWs between them at the most. Your motor is going to produce significantly more than this!

 

Surely the simplest answer is to replace the thermostat, if your motor is under guarantee Beta will send you one F.O.C. Don't email them 'phone them, I have always found them very helpful when talked to direct.

 

If your Beta is the same as mine then the calorifier circuit exits the motor directly from gearbox end of the the cylinder head and re-enters at the gearbox oil cooler assembly. This means that the thermostat will remain closed until the calorifier is up to a temperature similar to the thermostats setting. Once the returning water is hot enough the thermostat opens to allow hot water to the skin tank. As I mentioned above I doubt that your radiators (once the calorifier is up to temp) will dissapate enough heat to cool the returning water sufficiently to prevent the thermostat from opening. It can take a long time for the calorifier(s) to absorb enough energy to reach 80 degrees from top-to-bottom.

 

If your hot-out pipe from motor to skin tank gets warm/hot after a period of running then the system is working correctly in that the thermostat is open, but, is it stuck open or just not opening at the correct temperature? Talk to Beta and have it replaced, then you will know.