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| stuart turner thermostat ? |
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paul_brooking
| | Posted on Monday, October 14, 2002 - 02:05 pm: | 
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In my p55 the water goes in the exhaust cooler and comes out the cylinder head. It looks the same on photos of other p55 engines ive seen.
But in the story book ( I got from semidiesel.com) It mentiones a thermostat. I cant imagine how a thermostat could be used without completely changing the cooling, because it is a positive displacement pump, it cant just have the water stopped. The manul does not give enough detail to see whats going on.
I expect somebody Knows. |
bill
| | Posted on Monday, October 14, 2002 - 03:32 pm: |
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The thermostast would not stop flow, just redirect it. It is a 3 way valve. When cold, it probably recircs, when hot, it dumps the hot water. |
paul_brooking
| | Posted on Monday, October 14, 2002 - 06:13 pm: |
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Thanks Bill. I imagined it would have to work somthing like that. I think all the photos of engines I have seen do not have this device, it would be fairly obvious in the pipework.
I am thinking of possibly using the engine in a boat, and do not want salt water in the jacket, as this has already degraded to some extent, repaired etc.
I am thinking a solution to both these problems may be a heat exchanger using the original pump for sea water, and convection circulation on the engine. The height of the heat exchanger above the engine can then be adjusted to find a point where the temp is kept about correct. There will be little convection when engine cold. |
andrew
| | Posted on Monday, October 14, 2002 - 07:48 pm: |
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Paul,
As I'm sure you are aware, most engines with fresh water cooling would have a raw water pump and a circulating pump. How about using the existing pump for circulation and another pump driven off the crankshaft for pumping raw water through the heat exchanger?
Regards,
Andrew |
Tim Mulvey
| | Posted on Tuesday, October 15, 2002 - 06:21 am: |
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Paul,
As a P55 in a boat owner and about to restore one or two others I'd be very interested to keep in touch about the heat exchanger concept and other general P55 info.
I saw a heat exchanger on a blaxland engine owned by Boyd Myers that was on display at the Davistown Putt Putt Regatta, about an hour drive north of Sydndey in Australia - unfortunately its not shown clearly in any of the pictures posted by Andrew in the Boats with Early Inboards Section of the board under the thread "Davistown Regatta 2002" though there are some excellent pics of others engines - well done guys.
I'll get to the point - Barry Atkins (a friend of Boyd) previously posted pictures of this engine on 2 July 2002 under the thread "Aussie Blaxland Fans" (just search on any of these items). There are at least two photos of the engine with the heat exchanger - the chrome unit...
regards,
Tim |
paul_brooking
| | Posted on Tuesday, October 15, 2002 - 06:24 am: |
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Hi Andrew,
I know that would be the usual way of doing it, not only does it need a second pump, but also a thermostat. I thought I might manage to set up the system so it naturally provides temp. regulation, as mentioned above. Not realy sure if it would work though, the resistance to flow through the small connectors may be a problem for convection. Another problem is that the H.exchanger would need to be above the engine.
Of course another way to have nice non-corrosive cooling is a heat exchanger in the boat, such as a metal pipe outside in the sea. But again in this case I would need some method of temp. regulation.
Realy I am working on other bits at the moment and will have to decide about this later.
Many thanks everyone Paul |
paul_brooking
| | Posted on Tuesday, October 15, 2002 - 08:44 am: |
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\attach
You got me thinking it may be possible to use the change in displacement in the engine circuit to move a diaphram which is used to pump sea water.
obviously would not want much back pressure, but if the whole sea circuit was below sea level, very low pressure would be needed.
SEE ATTACHED WORD FILE
just a thought |
miro
| | Posted on Tuesday, October 15, 2002 - 11:15 pm: |
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My expereince with old engines in boats is that they are typically cooled too much, i.e. run almost cold I can put my hand on the engines while under full load with no problem - so it would seem to me that a cooling circuit made of a piping outside the hull in cool seawater makes a lot of sense. This is the technique used by steam boatsman ( steam boat persons???) to create exhaust steam vacuum and thus increase the efficiency of their set up.
It also seems to me that the cooling needs are rather modest for these old single cylinder engines.
miro |
paul_brooking
| | Posted on Wednesday, October 16, 2002 - 06:31 am: |
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yes it would be good for a condenser on a steam boat miro.
If the pipe was in the propeller area of the boat then its length could be adjusted so that at full power there was correct cooling, and the cooling would automatically be reduced as the power was reduced (because of reduced propeller flow).
I was trying to show a drawing of a heat exchanger with a diaphram between the two sides, in the cold water. so that pressure pulses are transfered to the raw water, for pumping.
I could not get the formatting tabs to work. Have tryed 2 computers , win 98 & win 2000. have heard others say this. obvously some can make it work.
Is there a browser setting needs changing ? |
paul_brooking
| | Posted on Wednesday, October 16, 2002 - 08:11 am: |
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Drag in the prop flow is even worse than drag on the hull.
Whats needed is a hollow rudder that can have fresh water flowing in it  ! |
andrew
| | Posted on Wednesday, October 16, 2002 - 09:16 am: |
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Paul,
If you are trying to post a photo or a drawing, it will work with any of the newer browsers. Did you read the instructions in the formatting section on the left? You can also email the photos to me and I will post them here.
Regards,
Andrew |
paul_brooking
| | Posted on Wednesday, October 16, 2002 - 11:27 am: |
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Think I may have got the attach to work
This is what I meant to attach before
Thanks Andrew, was just a bit of trial and error it must have the brackets
Paul |
paul_brooking
| | Posted on Wednesday, October 16, 2002 - 11:37 am: |
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V is an adjustable vent in the fresh water (with rust inhibitor) circuit.
if it is fully open it allows the closed circuit to vent so there is no pressure change.
If it is fully closed the pressure change in the closed circuit causes the diaphram to move, so pumping the sea water. There does not want to be an air space in the header tank. Safety pressure valve would be wise. but the idea is for the small vent to keep the closed circuit at atmopheric press.
Paul |
peter ogborne
| | Posted on Thursday, October 17, 2002 - 08:58 am: |
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Tim....if you have a look at a Chapman Super Pup engine on this site you will see the heat x that i made . Although i do not run this engine in a boat i agree with the thoughts that most of these old engines are over cooled . The Stuart Turners P5 And P55 both pipe the raw water through the exhaust first to overcome the too much cooling effect of cold sea water entering the cooling system .
Going back to the heat x . I made mine from a section of brass tubing . It was in fact a nice piece of windmill pump tube . I fabricated the tube plates and the tube bundles and used the original pump cylinder end caps with modifications . So the built in water pump circulates the fresh water and a chain driven bronze gear pump pulls in the raw water . I just put a globe valve on the raw water suction side to the gear pump ,this allows me to regulate the cooling effect . It all works very well and being brass looks great .
I have two Stuart Turners that i intend giving the same cooling mod .
All my engines never go to sea ........just rallys ! |
paul_brooking
| | Posted on Thursday, October 17, 2002 - 11:51 am: |
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Hi Tim, sorry did not mean to ignore you, I had not noticed your post until Peter refered you. You posted just before me while I was writing.
I only have one P55 and not in a boat yet, but this is the eventual plan (if wife will allow!).
I had no idea there was a thermostat used on P55s, you never see them in pictures. Acording to the manual the engine idles at 800rpm and full power at 1500. so thats about 1:2 in the water flow rate. the amount of fuel burnt at idle and full power must be in a ratio vastly greater than that. So even if the pump displacement was correct to keep the engine at temp. at full power , the thing would be too cold at low power.
But people say they are too cold even at high power. I notice in the manual the single cyl. pump has 20gal./h capacity and twin 50gal./h, so don't know why more than twice? |
peter ogborne
| | Posted on Friday, October 18, 2002 - 07:41 am: |
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I must apoligise ........I thought i had a pic of my heat x on this site ......I dont . I have a hard copy photo but as i am at the end of packing up for a shift to Albany 400 km south of here everything is packed ready for the move at the end of next week .
But if anyone is interested I will get up a sketch . |
paul_brooking
| | Posted on Sunday, October 20, 2002 - 06:06 pm: |
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I would be interested from anybody who has made a heatX from copper. from the very informative article on salt corrosion on this site it is obvious that it would be bad to use copper with iron in salt water, because the feric-chloride would eat the copper. but what if it was all copper ? I ask this because copper is readily available in pluming shops, brass is bit more difficult to get hold of.
Paul. |
Richard Day
| | Posted on Monday, October 21, 2002 - 08:28 am: |
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Have you considered a keel cooler. They were very common around the Chesapeake Bay in the late 20s onward. All they were was a length of copper water pipe 3/4" to 1" which ran along side the keel rubbing strip nearly the length of the hull. U turn at the bow and back to the stern area. Through hull fittings were connected to the engine through rubber hose. A small vertical expansion take made from approximately 3" dia. copper pipe fittings stuck up vertically along side the engine. The top of the expansion tank was a few inches above the head of the engine with a removable cap that had a small vent hole to keep the internal pressure at atmosphere and to fill the system. The engine ciculating pump was used to force the 50/50% antifreeze/freshwater mix through the closed system. Dry vertical exhausts were very common so no sea water pump was required to cool the exhaust line. Where a wet exhaust was desired a separate sea water pump would supply the cooling water injected into the exhaust line aft of the engine exhaust manifold. |
paul_brooking
| | Posted on Monday, October 21, 2002 - 08:29 am: |
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would be interesting to see how you did yours, but sounds like you are a bit busy at present so don't go to any trouble.
I made one a while back that I've never used with welded steel box that carries engine water, and copper tubes for sea water.
Paul |
paul_brooking
| | Posted on Monday, October 21, 2002 - 08:41 am: |
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Hi richard, the post one minute after yours was directed to peter by the way. We did mention this further up the thread, and it does seem a very attractive method. I think the only negative point is the possible increase in drag. Is the normal method to have the pipe in the water, or just cooled by splashes of water ?
Paul |
marks
| | Posted on Monday, October 21, 2002 - 07:56 pm: |
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Hello All,
This is an interesting discusion. I have been building a small lauch (the "irreducible") and am at the stage of fitting the engine( a small vinco).
I have spent a fair bit of time on chloride removal so this engine will not be seawater cooled.
Basically I have two plans on cooling this motor. The first and simplest is per Richard with a keel cooler of copper pipe and a dry exhaust.
The second plan is a counter cooler which is basically two tubes with one tube inside the other. The inside tube is copper and the outside tube is a high temp plastic/rubber( a bit like automotive heater hose).
The tube asembly is coiled and placed in a suitable container(for asthetic reasons only).
Seawater is fed into the outer tube and the engine coolant into the other end of the inside tube.
This is my prefered solution at this stage. I will be using only one pump(the existing one) which will handle the engine coolant.
The seawater will be circulated thru the tube and to the exhaust by way of a reverse venturi thingy of an old hall motor. The hall motors did not have a pump only the venturi.
I will be mounting a water temp gauge on the whole lot, just for peace of mind.
Of course the seawater will only circulate when the boat is under power.
The attraction of this system is that I have seen the tube assembly for sale at a home brew supply co. Apparently they use these things to quickly cool wort?.
As far as using copper in the cooling system I have no prblem with this as long as the chlorides have been treated to a reasonable level and the engine coolant is inhibited. In fact it may be possible to treat the chlorides this way with the engine in the boat and the right coolant mixture.
Mark S. |
Richard Day
| | Posted on Tuesday, October 22, 2002 - 08:25 am: |
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Richard, the keel pipe is always in the water and in a displacement hull I doubt the drag would even be noted. |
Richard Day
| | Posted on Tuesday, October 22, 2002 - 08:27 am: |
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Paul, The keel pipe is always in the water and in a displacement hull I doubt the drag would even be noted. |
paul_brooking
| | Posted on Wednesday, October 23, 2002 - 08:00 am: |
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I expect you are correct Richard the drag would not notice, there is a slight inconvenience for hull maintenance, though it could be made to remove easily.
Mark I like your idea with the venturi, I had actually wondered if this could be made to work, had not heard of a motor using it. If the H.X. and exh. outlet are as low as possible there would only be a few inches of water lift needed.
Presumably the venturi is used at the exhaust outlet.
Think I will make one.
Paul. |
paul_brooking
| | Posted on Thursday, October 24, 2002 - 07:58 am: |
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Mark would be interested in a few details of your thingy, could you breifly describe its construction.
Does it have a check valve so that when the engine is at low speed the water raised during a pulse does not fall back before it is expelled ?
What height can it raise from ?
An advantage of this system is that the water flow rate depends on exhaust flow, which is a much better indication of engine power than engine speed in the case of a pump.
Also a restrictor could be adjusted to get the correct engine temp.
If there is a check valve, an adjustment of this would enable low-speed against high-speed to be adjusted.
Cheers Paul |
marks
| | Posted on Saturday, October 26, 2002 - 11:54 pm: |
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Paul,
Probably the best idea is to give you the description from the Hall manual which I will try to find for you(i'm at work at the moment).
Basically it mounts behind the prop.
Mark S. |
paul_brooking
| | Posted on Monday, October 28, 2002 - 07:56 am: |
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Don't go to a lot of trouble Mark.
Mounts behind the prop ? I thought you were talking about a thing which is a venturi in the exhaust outlet, and sucks the cooling water through the system. |
kevin martinello
| | Posted on Thursday, June 03, 2004 - 06:51 am: |
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s.o.s.have chrysler 318 marine engines in my 30 ft tolly craft. problem: heat exchanger over-heating....tried blowing out air pockets, testing thermostats, heat regulator....nothing working. why is it over heating? what can i look at? what can i try differently? you seem to be a very informed and helpful site. would muchly appreciate any and all comments and suggestions....ty again. |
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