Exhaust temp alarm

[TorreyWP]

I ordered this last winter and just now got to the install.

The idea behind this little gadget is to monitor the temperature of the exhaust system after the raw water mixing elbow of the engine. A spike or gradual rise in temperature at this location can indicate either a restriction or sudden loss of raw water cooling (plugged strainer, bag or debris over inlet, cooked impeller...). This is an additional temp monitor to the coolant temp sensor which won't rise as quickly as the exhaust temp should there be a loss of cooling water flow which could cause more and more damage even a fire if the exhaust system components melt or get overcome by the excess heat.

A few sailboats I worked on back in Maine had a similar system but there was a fixed temp that would cause an audible alarm. This unit that I found out of the UK is a little different. Because the temperature at which the alarm should go off is sort of subjective, depending on engine, application and load. This system allows the user to monitor what is normal for your engine then set appropriate parameters.

http://www.siliconmarine.com/index.html

Ordering was easy, even with international shipping it was right around 100$ us for the digital display, there is also an analog gauge and a digital display capable of twin engine applications. I emailed David through the website, he accepts paypal which made things very easy.

Overall, I'm really pleased with how it operates and how simple the install was. I attached a few pictures, I also took the opportunity to upgrade my bilge pump system and added a new depth/speed display.

[rebuckley]

I like it - did you have an existing port in the mixing elbow? Or where does the sensor actually attach?
<edit> - I actually went to the page and that answered my question - - this looks like a great option!!

[RobS]

Good stuff, nice upgrades. Here's the download showing the sensor probe.

[WillieC]

I have a different temp sensor on my exhaust elbow that faithfully shows me when my impeller has failed. I am moving to a water flow sensor this winter.

Just read the instructions. Not so sure about drilling a hole in my exhaust hose.

[TorreyWP]

Gotta say I was not so sure about drilling into the exhaust hose either and of course I forgot to take a picture of that, I will next time Im on the boat and remember. Like the web site shows, the sensor come mounted in a ss hose clamp with o-rings on the sealing surface. I found the sensor install tidy and after about 8 hours of operating, no leaks have been noted. The instructions do say that if you want to, you can add some sealer to that area, I have not found that necessary, yet. I did also replace all the hard wall exhaust hose at this time.

[WillieC]

Torrey, please keep us informed of the longer term reliability. I would be concerned about hitting the wire coil in the hose, though maybe not all exhaust hoses are so constructed.

This alarm is one I have considered crucial, even though it was not early enough to save my impellers. I incorporated the audible with a little panel I fashioned to also sound alarm for low oil pressure. (The ancient A25s were not supplied with audible alarms. Couldn't hear them over the Volvo Pentas.) I will gladly swap an impeller than deal with an exhaust hose fire or worse. I have considered installing some kind of sensor on the engine coolant that triggers the audible, but pretty soon I would be sitting on my couch at home playing with boat apps on my computer. I do enough of that as it is. Maintenance, watch your gauges and have spare parts. Thanks for bringing this product to our attention.

Anyone have a good suggestion for a salt water flow sensor that would work on 5/8" hose?