Audable overheat warning

[castaway]

I have been intending to fitt an audable overheat warning to my Perkins 4108. I rather favour somthing I can strap/clamp on rather than fitting something intrusive..

Any advice/experiences? Suppliers?

Thanks Nick

<A target="_blank" HREF=http://www.yachtsite.co.uk/fairweather>http://www.yachtsite.co.uk/fairweather</A>

<hr width=100% size=1>

 

[Cantata]

Do you mean engine overheat, or exhaust overheat?
If exhaust, Index Marine do one that has a sensor that clamps onto the exhaust elbow, tells you loudly if the cooling water stops coming through.
www.indexmarine.co.uk - sorry I've forgotten how to embed a website name in here. Or they're at the LIBS if you're going.

<hr width=100% size=1>

 

[Talbot]

Talk to ASAP at <A target="_blank" HREF=http://www.asap-supplies.com/>http://www.asap-supplies.com/</A> they have what you need.

<hr width=100% size=1>

 

[supermalc]

I've done mine today. I have a YSM with an overheat switch (same as the thermostat switch on a car. Just fit a hooter, and wire to the switch. If you get an auto fan switch, this can be stuck onto any suitable part e.g. exhaust.

Malc.

<hr width=100% size=1>Malcolm. My opinion is not universally accepted, but is usually right.

 

[Avocet]

Maplins used to do a little kit with a remote probe and a digital readout. You can programme it to trigger at a pre-determined level and it can do all sorts of other things besides. If you just Araldite the sensor to a convenient bit of engine / exhaust (I drilled a hole in the top of a blanking plug on the cylinder head) you can alter the trigger temperature so that the alarm goes off when the engine / exhaust temperature is critical. It is powered by one AA battery and that lasts me about 2 years! The only problem is that I can't figure out how to make it power a large buzzer. I can hardly hear the little "Pizo" buzzer above the engine. I guess I need a switching circuit but don't really know anything about electronincs!

<hr width=100% size=1>

 

[Spuddy]

Your Maplin's kit sounds interesting - I'll look it up in the catalogue later.
Off the top of my head there are several switching options to output to a louder shrieker: power transistor plus more batteries or a relay and a secondary circuit? But how to get long battery life? I am but a poor woodwork teacher and there has got to be someone with the answer.
The other bit that that I would like more info on is where to put the sensor?
Is it best to sense when water stops flowing through exhaust - or is it too late by then?
Or on engine itself? Drilling holes makes me think - swarf in the bores. What does a blanking plug look like?
Hope to hear some answers.

<hr width=100% size=1>

 

[maxi]

£2.40 for a bi-mettalic switch of suitable rating, at RS. The footprint of the switch is smaller than a £1 coin plus two small mounting lugs. Easily attached to injection elbow and will drive a car hooter or any pietzo sounder.
Try part number 331-562.

<hr width=100% size=1>

 

[Dave_Knowles]

Not trying to be a profit of doom but don't rely 100% on these units. I was thinking of fitting one during the summer and the engineer (at a firm specialising in boat engines in Lymington) I spoke to said they often get called out to boats with overheating problems only to find that the exhaust sensor has gone wrong. He therefore said he would not bother fitting one as he felt them to be so unreliable and gave you a false sense of security.

On the otherhand I suppose as long as you are aware of their shortcomings it must be better than nothing.

<hr width=100% size=1>Dave
Southampton - uk

<A target="_blank" HREF=http://www.MyCleopatra.co.uk>The site for cleopatra boat owners</A>

 

[dickh]

The other method is to detect "No Water Flow" from the impellor pump. This will immediately detect if the inlet is blocked/failed pump before the engine begins to overheat. RS do a Flow meter, which is connected to a buzzer/horn which detects "NO water Flow". Both RS; Farnell & Maplin do these switches - about £20.
This method warns you early, so if you get an inlet blockage you don't ruin your impellor.
PM me and I can send a copy of the PBO article.

<hr width=100% size=1>dickh
I'd rather be sailing... /forums/images/icons/smile.gif