Electric pump for raw water cooling?

[SteveTibbetts]

Please ignore the following if you're the 1 in 93 people who've looked at my 'wanted' ad and thinking about offering me your spare Yanmar YSE water pump...

Having priced up parts for repairing my YSE8 water pump I've decided the centre spindle might not be so bad after all and could be worth trying with a new seal.

If it doesn't though..

Having mentioned the price to a non sailing friend he suggested using an electric pump. My first thoughts were "don't be silly" but couldnt really think of a reason not to. The pump will only run with the engine.. the engine will maintain the battery charge..

Some erudite reasoning to stop this mad idea would be most welcome!



Steve

 

[lw395]

Electric cooling pumps are not uncommon in rally cars etc.
That's a circulating pump of course.



The impeller pump needs to pump enough water to cool at max power, but not too much for the exhaust to clear at tickover. So one that runs at a speed proportional to engine RPM seems like a good idea. Not sure how you do that with an electric pump?

My Yanmar 1GM impeller pump spindle leaked a little but I cured that by polishing the ridge off with wet and dry, and fitting a new seal.
It may be possible to sleeve the shaft and fit a different seal?

 

[Mrnotming]

Freshwater cooling electric pump

There was a firm called Martec who supplied freshwater cooling kits.Lots of pages come up when searched, but perhaps they have gone or been taken over Vic S may know?

 

[maby]

There was a firm called Martec who supplied freshwater cooling kits.Lots of pages come up when searched, but perhaps they have gone or been taken over Vic S may know?

Martec are still around - we had one of their fresh water cooling conversion kits on our previous boat. But it is an add-on for the original cooling system, not a replacement - it does require that the original raw water cooling system is in good condition.

Aquafax are Martec's distributor in this country.

 

[boguing]

We are living in exciting times. It is finally beginning to look like the end of the internal combustion engine.

So, yes an electric motor could work well. But it does need to have variable speed to avoid under or over-cooling. That mechanism could push the cost into the 'no' zone.

But with an accurate temperature gauge and a handy switch, it could be managed.

I did advise this setup on a competition car, and it is working for them. They do have the option to switch on a cooling fan too - so have a bit more control over cooling rate.

 

[Blueboatman]

Didn't Fullcircle solve this one by organising an engineering firm to turn up a new shaft for him on their lathe? I seem to remember, perhaps Google will as well.
Seals are cheap. Sticking existing shaft in a drill and smoothing with wet and dry sandpaper is cheap, taking it along to the local bearing suppliers to select a seal for the newly polished and worn diameter 'should' be cheap too.
Changing seals every year though, a pita.
.
I have heard of people getting home with in an emergency using a jury rigged bilge pump with inlet restrictor ( spare lever valve) but regulating the water flow appropriate to engine temperature as the revs and workload rises would be key...

 

[boaterbaz]

Quite a common set up on small fishing craft is to have the bilges and seawater inlet connected in such a way that the bilge can be pumped via the engine raw water pump or sea water pumped thro the engine via bilge pump. Memo to self. Do not connect the sea water inlet to bilge! It upset my then skipper.

 

[lw395]

You might find it easier to run a jabsco pump from a belt than to make an electric one fool proof.

 

[bert49uk]

wondered if this was any good http://www.vsm.skf.com/en-US/HeavyDuty/KitsAndTools/SpeediSleeve.aspx
cant remember the shaft size, these go from 12mm

 

[prv]

So, yes an electric motor could work well. But it does need to have variable speed to avoid under or over-cooling. That mechanism could push the cost into the 'no' zone.

But with an accurate temperature gauge and a handy switch, it could be managed.

Surely the engine thermostat would regulate the temperature, though? You could run the pump at full speed and let the 'stat take as much water as it needs, the rest going through the bypass. I would think the reason not to always pump at full speed is that at low revs there might not be enough exhaust to push all that water up out of the trap, not because the engine will be over cooled.

Pete

 

[Ruffles]

Having priced up parts for repairing my YSE8 water pump I've decided the centre spindle might not be so bad after all and could be worth trying with a new seal.

Steve,

If you have a slight ring on the shaft consider a twin lip seal. The two seals will (hopefully!) be either side of the ring.

Available from Simplybearings amongst others.