pyrometer - excessive EGT temp

[simonfraser]

am i worrying too much here ?
there does not apear to be a temp sensor for the exhaust gasses on most turbo diesels. mine KAD44 EDC

if there is a cooling problem the engine is going to suffer major damage b4 this is noticed, correct ?
i am about to fit an alarm on my bilge pump, but will this go off in time to prevent engine damage if i have a water cooling leak into the bilge ?
obviously wont go off it there is a loss of flow, so still a problem.

a pyrometer EGT has to be fitted to the exhaust pipe, of the engine b4 it enters the turbo.
this requires the part to be removed, hole drilled and a suitable nut to be fixed on the exhause pipe.

is this all worth it ?

 

[MapisM]

am i worrying too much here ?

The subject has been discussed in this recent thread, but I suppose that the short answer is who knows?

if there is a cooling problem the engine is going to suffer major damage b4 this is noticed, correct ?

100% correct.

i am about to fit an alarm on my bilge pump, but will this go off in time to prevent engine damage if i have a water cooling leak into the bilge ?

No way.
In fact, you can actually run on too high EGT for hours (hence with potential engine damages), without leaking one drop of water inside the e/r.
A bilge alarm is very nice to have - no, wait, rather essential than nice. But it serves a totally different purpose.

a pyrometer EGT has to be fitted to the exhaust pipe, of the engine b4 it enters the turbo.
this requires the part to be removed, hole drilled and a suitable nut to be fixed on the exhause pipe.

Yup, but not necessarily "b4" - see previously linked thread.
Besides, you might have already a threaded hole somewhere in the initial dry section of the exhaust (after turbo), as I do.
That depends more on the builder choices, than on the engine type/manufacturer.

is this all worth it ?

Good question.
Maybe not, if all the boats cruising without any EGT sensors are anything to go by.
But maybe yes, if and when you would have a problem with yours...

 

[volvopaul]

am i worrying too much here ?
there does not apear to be a temp sensor for the exhaust gasses on most turbo diesels. mine KAD44 EDC

if there is a cooling problem the engine is going to suffer major damage b4 this is noticed, correct ?
i am about to fit an alarm on my bilge pump, but will this go off in time to prevent engine damage if i have a water cooling leak into the bilge ?
obviously wont go off it there is a loss of flow, so still a problem.

a pyrometer EGT has to be fitted to the exhaust pipe, of the engine b4 it enters the turbo.
this requires the part to be removed, hole drilled and a suitable nut to be fixed on the exhause pipe.

is this all worth it ?

EGT sensors are sometimes fitted when builders and engine suppliers test new design build boats , then system design is agreed signed off etc, then the builder builds the boat to that design.
I'm really at a loss why you want to fit a sensor, there are simple sensors on the market that will cut in sounding an alarm by halyard , mostly standard fit on most larger shaft drive boats, my last Phantom 43 had one.
The idea of this is to work if you lost an impeller or had a sea water inlet blockage , the exhaust temp rises and the alarm sounds, however at about the same time the engine would be on the point of overheat and therefor volvos own system would sound, all assuming of course your system is in good order.

I gave you some info where to fit the sensor, reading your post I think you have misunderstood, you need to fit it approximately 4inches after the exhaust elbow, I am assuming you have a shaft drive boat?
Do you have any manufacturers infonas to what the max temp should be for your engine and exhaust design?

 

[simonfraser]

'The idea of this is to work if you lost an impeller or had a sea water inlet blockage , the exhaust temp rises and the alarm sounds, however at about the same time the engine would be on the point of overheat and therefor volvos own system would sound, all assuming of course your system is in good order'

Is not the concern that during a malfunction the EGT gets too hot way b4 the engine water temp increases ?
Or has the KAD 44 EDC other sensors to warn of impending trouble b4 the cooling water temperature rises too high ?

 

[simonfraser]

Two choices with an audible alarm by the looks of it :

https://trickettmarine.co.uk/nbsp-12v-single-engine-alarm.html
Here we are measuring the temperature of the outside of a metal pipe, which is water cooled
Set to go off at 200F

Or

http://www.cactusnav.com/nasa-exhaust-temperature-monitor-p-12646.html?cPath=1010
Here we are inserting a probe into a flexible hose, max temp measured is 200C and an alarm can be custom set

But EGT can be a lot higher ??? Or not on a KAD 44 / water cooled diesel which is running correctly ?
I dont understand .....

 

[volvopaul]

'The idea of this is to work if you lost an impeller or had a sea water inlet blockage , the exhaust temp rises and the alarm sounds, however at about the same time the engine would be on the point of overheat and therefor volvos own system would sound, all assuming of course your system is in good order'

Is not the concern that during a malfunction the EGT gets too hot way b4 the engine water temp increases ?
Or has the KAD 44 EDC other sensors to warn of impending trouble b4 the cooling water temperature rises too high ?

Yes the kad 44 does have its own overheat alarm for the closed circuit system, it has a thermoswitch located in the exhaust manifold which sends a signal to the dash mounted module sounding the audible alarm , I'd take a look in your vp handbook , you can also test the alarm function by pressing the black rubber button on the dashboard.

 

[simonfraser]

Yes the kad 44 does have its own overheat alarm for the closed circuit system, it has a thermoswitch located in the exhaust manifold which sends a signal to the dash mounted module sounding the audible alarm , I'd take a look in your vp handbook , you can also test the alarm function by pressing the black rubber button on the dashboard.

Perfect tnx Paul.
I will go and look.

 

[Portofino]

'The idea of this is to work if you lost an impeller or had a sea water inlet blockage , the exhaust temp rises and the alarm sounds, however at about the same time the engine would be on the point of overheat and therefor volvos own system would sound, all assuming of course your system is in good order'

Is not the concern that during a malfunction the EGT gets too hot way b4 the engine water temp increases ?
Or has the KAD 44 EDC other sensors to warn of impending trouble b4 the cooling water temperature rises too high ?

What we have too is "inlet water pressure " guage on one page -this monitors the strainer function and if the impeller is doing its job on the seawater side
We also have coolant pressure in millibars too -this monitors if there's a leak and tells us it's pressured up and working properly on the closed side .

Water temp of the closed side sits @ 84 ( when warmed up ) irrespective of all else -only dropping to 81 @ tickover during mooring after a run .

The EGT is very variable , depends on rpm moves rapidly with rpm while the water temp above does not move
Eg EGT can be 250 or 650 approachig WOT while water temp sits @ 84 .

I Allways take the EGT and load to be a function of fouling and weight .
Clean props and less weight lower them .
I adjust the rpm and speed of a fouled ( dirty props until I clean them ) to keep the EGT below 600 ish .

Ita also surprising the influence of weight ,full tanks etc -this is because the boat although seems to only sit a few cm deeper in the water ,on the plane it will sit a bit deeper = more drag .
Drag is the EGT riser in the same way as fouled props and bottom ,the extra weight just sinks it in even though it's clean .

So those without EGT ,s guages accepting prolonged running @ excessive EGT leads to cumulative damage of marine diesel engines
I would advise the following in the interest of engine health Longevity

Clean props -first and formost
Clean hull - for Uk if you need a scrub
Keep the weight down --- revisit yor cruising stores , keep. Mindful eye on add ons

Take it easy until all of the above are as near to factory spec