Improve low-speed water cooling

[atoyot]

I though I'd share with the readership a trick I tried out that's working quite well, at least in the test phase.

We all know that the Seagull, when working properly, discharges a pencil-thickness stream of cooling water when running at about 1/3 speed or better. I wanted to see if I could get enough water flow at nearly idle ('tickover') speed, for dock approaches and also for photo opportunities when dolphins come up near our boat, which I might add is not uncommon.

The problem is of course that the centrifugal impellor theory only works if the impellor is spinning fast enough to throw water up more than half a metre in height, on a longshaft Seagull. I'm not complaining about it, simply reviewing some facts. Now, what if he impellor and pump were responsible for raising water less than 15-20cm? That would be easier to achieve at very slow running speeds (or for that matter, it would be easier to do at any speed).

Enter now, the principle of the siphon. If we had a closed water system from the pump up to the head and then from the head's water discharge tube back to near ocean level, once the circuit is full of water the force needed to circulate it will be negligible.

What I did was to find a short piece of flexible hose that makes a tight fit into the discharge hole. It happens that the hose I used will snugly seal over some semi-rigid, thin-walled 1/4" Teflon laboratory tubing. I used a trace amount of gasket sealant on the flexible hose where it goes 8 or 10mm into the discharge hole, applied the tubing, and used stainless steel aircraft safety wire to lash the tubing to the exhaust tube in three places. Now, when running, I still have to run up the engine a bit to start water flow (as before), but after the flow has started I can decrease throttle to dead slow running and lukewarm warm water still comes out of the now-extended discharge hole.

It works, and if removed, will not impact the appearance of the original Seagull.

Now along with this, I"ve wondered what would happen if I replace my Fourty Plus OEM impellor with one made for the QB series that has eight blades rather than 4 blades. Even if I had to trim the blades down a millimeter or two, it would be twice the blades. Any comments?


-Ted

[Collector Inspector]

dolphins ? Seagulls?

Not really a match Mate!

Regards.

[atoyot]

dolphins ? Seagulls?

Not really a match Mate!.

I'm sure I missed the point



EDIT: OK - A bit dirty running, these things. Sorry.

[Hugz]

I've found a well tuned seagull will idle with out overheating. Might also explain why the century was introduced with the cooling fins on the head. The 102 does have a longer water tube outlet before it ducks into the exhaust which may already have an element of siphoning happening. Interesting experiment tho.

Feeding dolphins oil and carbon-monoxide may not be such a good idea.

Hugo.

[sophie]

Brilliant idea. Well done, a really good example of problem solving. I will try the idea on my Kingfisher, I have been wondering about idling/cooling while picking up moorings. Thanks for the idea mate.

[Hugz]

Of course an old aussie bushtrick for a hot motor is to shake up a can of VB and spray the motor. As it is froth it doesn't cool too quickly causing cracks. Good fire extinguisher too. Yep... should always have a beer handy!

[atoyot]

I've found a well tuned seagull will idle with out overheating. Might also explain why the century was introduced with the cooling fins on the head. The 102 does have a longer water tube outlet before it ducks into the exhaust which may already have an element of siphoning happening. Interesting experiment tho.

Feeding dolphins oil and carbon-monoxide may not be such a good idea.

Hugo.

Here's a short flick of this engine - http://www.youtube.com/watch?v=cfjpVoazL2Q

I've got it tuned, i.e. running smoothly and the head passages are clean as a whistle. If taking a 102cc inpellor and trimming it down to fit almost to the point of contact but not touching would give me some flow at idle, I'd do that.

On the dolphins, the truth is that I'm generally under sail when they come around. This seagull I have now will mostly be a brag item and a novelty for the two of us who need something to fart with in the off season. It'll probably come out often enough to get used to, though. Most of the time in foreseen good weather, I plan on using the modern engine, a lightweight 4-stroke.


Thanks,

Ted

[Hugz]

Yep, most dolphins like riding the bow wave so prefer the vessel moving. Cheeky buggers they are! Are there dolphins around England?

Where are these bloggers that you mention on you tube?

[atoyot]

Yep, most dolphins like riding the bow wave so prefer the vessel moving. Cheeky buggers they are! Are there dolphins around England?

Where are these bloggers that you mention on you tube?

Nowhere specifically, but certainly here among other places. I can't dismiss the tiny bits of anecdotal lessons picked up on http://www.trailersailor.com, http://www.sailinganarchy.com, etc etc etc. If I bookmarked every useful site, I'd run out of room but I'd like to have done so anyway.

I'm on the eastern seaboard of the US, and sail the mouth of the Delaware Bay. Actually, it's most often just inside Cape Henlopen's Harbor of Refuge at Lewes, Delaware http://en.wikipedia.org/wiki/Cape_Henlopen, http://www.delawarebaylights.org/ My little boat has about zero freeboard and is more suited to lakes and rivers, though it seems to do well out there if the waves aren't too chaotic. It's amazing what one can see on the beach with a good pair of binoculars, from a mile out. And as long as the beer, sardines and cheese hold out, we're good.

Most of the time the dolphin community simply passes by one way or the other, or may come up behind and follow on our aft quarter for a bit. I don't know if this enters into it or not but when the sailing partner plays his Ipod into our small amp and flush-mounted cocpit speakers, they tend to stick around longer or closer. We were in the midst of a pod of perhaps 50 or so one time, probably chasing a school of feeder fish. That was incredible and of course we didn't have a great camera along at the time.

There is this lucky shot, though, from last year's family holiday, if you like.



Note the kicker engine that was on there at the time - that was made back in the 1980's by Hawaii Motor Corp and is called a Cruise 'N Carry.... about 35kg soaking wet. It's overall construction is remarkably like a Seagull - the piston skirt cutoff, the operation of the carbeurettor/needle valve, the simplicity of construction. The engine block itself was used in leaf blowers, concrete saws and other industrial tools made by Shindawa, and it's a LOUD s.o.b.! But it pushes every bit as well as our Honda 2hp 4stroke, and so we keep the C.'N C. in it's factory cover, up front in the hold in case any other engine we're using should give out. Not like it takes up room or anything. That engine was in use on that sail because our 4hp Evinrude threw a connecting rod while getting away at the launch site.

[Collector Inspector]

A Bit like Anzani has.

Sort of closed loop.

Very Efficient.

[Charles uk]

Here in the UK we never mention the dolphins, porpoises, seals, basking sharks, sun fish or the tuna just in case the Aussie long liners hear about them & want to put them in cans!

[Collector Inspector]

Charles.

Laugh! Nearly Split!

Um, we do not do fishing in Oz any more.

Coz of Western Australian Government wants to stop fishing.....Bad for everybody by the look.

http://www.fishingtaxgrab.com/

Maybe you lot could send an Email from "Over There"

Regards

[timberman2004]

low speed cooling ???
why would you bother ??
Seagulls happiest bieng well worked ...water temp self regulates to about bath temp

as to dolphins and all the rest ...agree with Charles ...reach for the harpoon before the Aussies get in on the act

Ummm ....i do believe WE WON THE ASHES

seen Ricky Pontings post match interview ?? such a humble Aussie ...god that must have hurt !!!

[Hugz]

low speed cooling ???
why would you bother ?? Seagulls happiest bieng well worked ...water temp self regulates to about bath temp
as to dolphins and all the rest ...agree with Charles ...reach for the harpoon before the Aussies get in on the act
Ummm ....i do believe WE WON THE ASHES seen Ricky Pontings post match interview ?? such a humble Aussie ...god that must have hurt !!!

Things are very rosey down here....what recession?? Pleased you guys have the ashes, you need something uplifting

Seriously... does Oz have a reputation for overfishing? We have a huge problem of international fish poachers ie Japs etc.

[atoyot]

low speed cooling ??? why would you bother ?? Seagulls happiest bieng well worked ...water temp self regulates to about bath temp

How long does one suppose the Seagull can run at bare minimum without cooling water? This assumes the head is full of water that was cranked in there from running up a little first, boiling like a tea kettle as it may. If that period's not a full minute or two then that's part of the reason. The real reason is simply to see if it could work. I doubt we'll really use it much. The exit stream is a lot more voluminous without the tube, but seems about the same temperature as the stock exit water.

We found it handy yesterday when we wanted to sneak up on some osprey and a grey heron with a camera... to the extent that one can sneak up on wildlife with a virtual machine pistol pat-pat-patting in the background. We just inched along at bare steerage just fine, with cooling water fully functional.

So it's mostly an experiment for the sake of it.