cooling water flow detector

[Graham_Wright]

Having just had a fright, I think I need one of these.

Recommendations please.

 

[Refueler]

Doesn't it exit with exhaust ? or via own outlet ?

 

[Graham_Wright]

Doesn't it exit with exhaust ? or via own outlet ?

Yes - but that's "round the back"! A jabsco impeller doesn't take long to destroy itself when dry.
There is a device called "Aqualarm" which dangles a paddle in the flow but I can't find a seller (in the UK).

 

[Keith-i]

I have an aqualarm which I bought a few years ago from a UK source. It has actually recently stopped working so I'm currently on the hunt for a supplier too. I'll let you know if I find one.

 

[LoneHort]

Available here AQUALARM Coolant Flow Detector from 149,95 € buy | SVB

 

[Graham_Wright]

I have an aqualarm which I bought a few years ago from a UK source. It has actually recently stopped working so I'm currently on the hunt for a supplier too. I'll let you know if I find one.

Do you want to sell it?

 

[Kwik Decision]

One of these will quickly tell you you've lost cooling water, although not quite as quick as a flow alarm...
SM010
I should be on commission, that's the second time I've recommend this is two days. No connection with Silicon Marine, apart from being a happy customer...

 

[LittleSister]

Exhaust temperature alarm or alarm/temp readout. Much faster response than engine temperature warning. Cheap and easy to fit.

e.g. Home: Silicon Marine
(other brands available)

 

[Graham_Wright]

Neither of these protects the jabsco (fast enough).
There's a variety on ebay
Water Flow Detector Turbo Type Flow Switch Temperature Resistance Flowmeter | eBay
but they are all too small in diameter.

 

[LittleSister]

I imagine the exhaust temperature would rise very fast once there's no water cooling it. (Can anyone comment from experience?) Certainly faster than the temperature of the impeller.

Once it's wet, your Jabsco should be quite happy flapping around empty for a few minutes. I am sure I am far from alone in having run for a few minutes with the inlet blocked or seacock closed without ill effect.

Speedseal used to do a version with a Teflon(?) disc behind the cover plate that could run dry for over IIRC 20 minute (I had one), but sadly the business closed and I'm not aware of anyone stepping into the market with anything similar. (I never did understand, though, why just reducing the friction on the front face achieved that, when the outside and rear faces that the impeller bears on remain unchanged.)

There's always the low tech solution - run a 'piddle tube' from the cooling anti-syphon loop to drain into the cockpit. You can positively see and hear whether the coolant is flowing at all times. Instantaneous response, but no alarm as such.

 

[Keith-i]

Do you want to sell it?

A bit pointless really seeing as it doesn't work any longer and is not user serviceable. It's a 2" one too.

 

[Graham_Wright]

A bit pointless really seeing as it doesn't work any longer and is not user serviceable. It's a 2" one too.

I like fixing things!

 

[Aquanaught]

I can vouch for the Silicon Marine exhaust temperature alarm - relatively cheap, easy to fit. After fitting and running engine taking temperature readings, you can set the alarm level to activate not far above the max. temp you will get at full throttle (say +20 deg.) so you can get a quick response to either blockage of impeller failure.

 

[earlybird]

I fitted one of These. The thermistor was fixed to the outside of the exhaust elbow downstream of the water injection point. A loud buzzer was wired to sound if the selectedtemperature was exceeded.

 

[jamie N]

It's a good thread, as it's reminded me that I'm slightly vulnerable with this matter, so I've just bought these from a jungle provider.

 

[PlankWalker]

I have a Piddler, it is simple, requires no power, and tells you immediately if you have a cooling problem.
Tee of a 6mm hose from your raw water system after the pump.
Take the hose above the water line to a fitting in the cockpit, preferably this fitting is directly above a cockpit drain.
As soon as you start the engine it should piddle, as soon as you switch off it should stop piddling.
If while running the engine the flow stops , decreases, or increases, you have a problem!

 

[Keith-i]

Surely a piddler requires constant monitoring whereas a system with an alarm does not require the same attention.

 

[pandos]

Having started the engine without opening the seacock once or twice....I often wondered is a vacuum gauge is the way to go....if there is a blockage the vacuum increases if the pump fails vacuum will drop....

In the ideal world an exhaust temp alarm and a vacuum gauge would be very useful...

 

[Daverw]

Having started the engine without opening the seacock once or twice....I often wondered is a vacuum gauge is the way to go....if there is a blockage the vacuum increases if the pump fails vacuum will drop....

In the ideal world an exhaust temp alarm and a vacuum gauge would be very useful...

Or pressure differential switch across inlet and outlet of pump

 

[superheat6k]

I have recently bought Aqualarm flow switches and combined exhaust temp alarm panel direct from the US. Fitting these is an early priority for Billy Ruffian. I have a recent thread running on this - let me know if you want a reference.

Having near wrecked an engine on my Corvette these for me are a no brainer.