Engine Running Temp Check

[Thallac]

Hi
I have a Mitchel Sea King with two Bukh DV48
I have had a temperature sender issues, with the alarm going off. (Which i think is a lose connection)
As a precaution i decided to measure temp on a run with a laser thermometer.
I took the boat from Walton to Kew so was stop starting at locks, but managed to get her up to a steady 2500 revs on the last hour on the tidal stretch of the Thames (Boat was running for about 3-4 hours)

Here were the maximum readings

Port
Oil Filter 96
Top of heat exchanger/radiator 71
Front of head 69

Starboard
Oil Filter 90
Top of heat exchanger/radiator 60
Front of head 75

Do these sound okay.

I was thinking of buying back on temp alarms, as follows

For wet exhaust http://www.siliconmarine.com/sm007d.html
For engine something like this https://www.ebay.co.uk/itm/DC-12V-B...382089?hash=item4d76216609:g:udgAAOSww7RbLDTX

Any views

Thanks

 

[VicS]

Hi
I have a Mitchel Sea King with two Bukh DV48
I have had a temperature sender issues, with the alarm going off. (Which i think is a lose connection)
As a precaution i decided to measure temp on a run with a laser thermometer.
I took the boat from Walton to Kew so was stop starting at locks, but managed to get her up to a steady 2500 revs on the last hour on the tidal stretch of the Thames (Boat was running for about 3-4 hours)

Here were the maximum readings

Port
Oil Filter 96
Top of heat exchanger/radiator 71
Front of head 69

Starboard
Oil Filter 90
Top of heat exchanger/radiator 60
Front of head 75

Do these sound okay.

I was thinking of buying back on temp alarms, as follows

For wet exhaust http://www.siliconmarine.com/sm007d.html
For engine something like this https://www.ebay.co.uk/itm/DC-12V-B...382089?hash=item4d76216609:g:udgAAOSww7RbLDTX

Any views

Thanks

I'd expect a bad connection on the temperature sensor or in the wiring to render it inoperative rather than give false high temperature alarms .... but the sensor itself could be faulty causing false high temp alarms

Specified temperature for indirectly cooled engine is 70 to 95 C so your measured temperatures do not give cause for any concern ... but it is an incredibly wide tolerance! One might even be running a trifle cool.
At some point when having nothing much better to do or when next draining the cooling systems I might check the thermostats. They should be marked with the temperature at which they just begin to open.

The workshop manual for the engine I have open shows a high temp alarm and a temp gauge both being driven by a combined , 2 wire, sensor but you do not mention temperature gauges ??

An exhaust temp alarm could be a worth while addition as it will give an early indication of loss, or restriction, of cooling water flow, before it shows up as a high engine temperature.

 

[NealB]

I read somewhere (maybe in ybw, but I can't find it) about someone who fitted a NASA exhaust temperature sensor into the thermostat housing, to give coolant temperature.

Edit - it was this: http://www.jeanneau-owners.com/hintsandtips/enginetemperaturemonitor.html

 

[VicS]

I read somewhere (maybe in ybw, but I can't find it) about someone who fitted a NASA exhaust temperature sensor into the thermostat housing, to give coolant temperature.

Edit - it was this: http://www.jeanneau-owners.com/hintsandtips/enginetemperaturemonitor.html

I initially suggested that the OP should look at that ( https://www.nasamarine.com/product/ex-1-exhaust-temperature-monitoralarm/ ) but then realised that for only £20 more the Silicon Marine instrument will monitor both engines.

 

[LittleSister]

The little circuit board which operates the same alarm from several different sources (temp, oil pressure , etc.) is not Bukh's finest and most reliable feature. Don't overlook that as a possible source of your problem.

 

[Thallac]

Thanks for your reply.
It is good to know engines are not running hot
I have found this for the engine temp http://www.fullwavemarine.com/tempgauge.html
Thanks again

 

[ottow]

Lots more variants on the manufacturer's page.
http://enginewatchdog.com/index.html
I have the 2 sensor version myself, for engine and exhaust alarms. As I recall I simply specified the text I wanted in the display for each alarm and they set that before shipping.