[C38] Fwd: Re: Vented loop in cooling system

Max Soto maxsoto at gmail.com
Mon Nov 7 10:36:33 EST 2011 

This is the first drawing that I have seen where it is located before the
heat exchanger,. I gues (just guess!!!)  that it won't make that much of
a difference if the vent is located after of before the cooler, as long as
it is located after the saltwater pump... Just my thought!!! Regards, max

2011/11/7 Don Strong <drstrong at ucdavis.edu>

>  Guys: I worried about this all night long and found a description of the
> system that is on Discreet Charm.
> http://www.myboatsgear.com/newslette...nt%20drown.pdf<http://www.myboatsgear.com/newsletter/images/northern%20lights%20dont%20drown.pdf>.
> Thanks for bugging me about it, and I apologize again for bolixing the
> description.
> Regards, Don
>
> -------- Original Message --------  Subject: Re: [C38] Vented loop to
> muffler cooling injector, yes!  Date: Sun, 06 Nov 2011 16:19:35 -0800  From:
> Don Strong <drstrong at ucdavis.edu> <drstrong at ucdavis.edu>  To: Catalina 38
> Listserve <listserve at catalina38.org> <listserve at catalina38.org>
>
> You are right and so is Steve. Your statement brought the cooling
> circuitry flooding back into my brain.  I had forgotten the circuit for the
> water when I wrote the first bit.  (I've been working too much and haven't
> thought about the boat enough lately).
>
> The water pump takes seawater from the the seacock at the through hull via
> the water filter. The water pump sends water to the cooler, which sits on
> top of the engine. The cooling water exits the rear of the cooler, goes to
> the the fiberglass box water lock then to the vented loop (or vented loop
> first, before the box?). From there, the sea water squirts into the
> injection riser of the manifold and into the muffler.  I think I remember
> this correctly but don't have a diagram here.
>
>  Gawd, I gotta get out more often.
>
> Thanks you guys for straightening me out!
> Regards, Don
>
>
> On 11/6/11 3:24 PM, Max Soto wrote:
>
>
>  Ups! Pressed send without having finished the message!!!
>
>   Don,
> According to the Catalina drawings, That is the original vent location for
> the C38.
> I'm with Steve O  on the vented loop issue.  This vent is supposed to
> avoid flooding of the muffler and then the engine when you turn it off.
>
> That's why it needs to be located in the hose right before the elbow
> riser.
> I wouldn't use it before the saltwater pump. That could bring some new and
> unexpected problems....
> Max
>
>
> Sent from my iPod
>
> On Nov 5, 2011, at 8:17, Don Strong <drstrong at ucdavis.edu> wrote:
>
>   Steve:
>     Thanks for thinking about me. Yes, the vented loop is is at the top of
> a hose run of about 2.5 feet straight up from the seacock that brings in
> the sea water for engine cooling. The hose then runs from the loop to the
> cooler.  The loop is screwed to the bulkhead at the forward end of the sail
> locker. Dunno if install was part of the earliest engine (Atom4 or
> Weserbeake?), but the Yanmar installer did leave it in place.  I believe
> that the vented loop is there to prevent seawater from siphoning to the
> engine when it is not running. There is no question that a good bit of the
> engine is below the water line when the boat heals.  I don't want to have
> to shut off the through hull every time I shut off the engine.
>     The brass vent device present at purchase dripped.  The drip ran down
> the line and onto the starter, which it ruined. I replaced the starter, and
> the brass vent with a Marelon vent.
>     These old boats are enjoyable for me. I really do love worrying about
> all of this stuff, but I don't want it to get too much more expensive. My
> wife once said that I might enjoy an even older boat even more.  I replied
> "how about two old boats."
>
> What do you think about the siphoning concern? What do others think?
>
> Regards, Don
>
> On 11/4/11 10:29 PM, S Orton wrote:
>
>  Don,  Your email indicates you have a "vented loop" for your engine sea
> water cooling?  To me that doesn't sound like a good practice, as you could
> loose your cooling to your engine with a vacuum breaker on the suction side
> of a pump.  The scenario- marine growth partially plugs the
> intake, negative pressure increases on the pump suction, the vacuum breaker
> opens, and lets air into the pump suction loosing sea water flow.  I would
> definitely check into this.
> Cheers, Steve O
>
>  ------------------------------
> Date: Tue, 1 Nov 2011 08:44:23 -0600
> From: maxsoto at gmail.com
> To: listserve at catalina38.org
> Subject: Re: [C38] Vented loop for head discharge
>
> Steve,  Since the loop+vent breaks the siphon, the "pressure" on the joker
> valve is from the grey water located between the head and the loop.
> Don, same thing happened to the PO, so he made a box that raises the head
> about 7 inches, and added a vented loop to the intake hose.  Apparently he
> found he boat with 1' of water. I think that the vented loop for the intake
>  is enough, so I'm going to remove the riser box. Short people have their
> feet on the air while seating in the head!
>
>  Regards,
>
>  Max
>
> 2011/11/1 Don Strong <drstrong at ucdavis.edu>
>
> Steve: I did the vented loop head-to sea retrofit because my insurer
> demanded it.  Big job! The exit hose goes up the along the hull, through
> the sink top and reaches an apex are just under the deck. The vent is at
> the apex. The loop+vent breaks the siphon. I don't see how the grey water
> problem is any different between "overboard" and "waste tank." When the
> valve is thrown to tank, grey water sits behind the joker valve just as it
> does when the valve is thrown to overboard.
>
> I also installed a vented loop for the sea water intake for the head after
> we awoke with 6" of water in the boat (someone "moi?" was too sleepy to
> flip the switch to "dry bowl during the night).  There is also a vented
> loop on the sea water intake for engine cooling. I recently replaced the
> vent.
> Don
>
>
> On 10/31/11 11:43 PM, Steve Smolinske wrote:
>
>  Question for anyone with a vented loop in their head discharge.
> Looking at it on paper it seems that the pressure of the grey water in the
> section from the head to the vented loop would be enough to leak back into
> the toilet bowl.  I know there is a duckbill valve and a flapper valve in
> the head to stop the reverse flow, but as we all know if you leave the
> discharge seacock open the head will fill up.   Does the vented loop work
> because the head pressure of the grey water in the run from head to loop is
> not as great as that coming from the seacock?  Any experiences are greatly
> appreciated.   Thanks
>
> Steve
>
>
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>
> --
> Donald R. Strong
> Professor
> Dept. of Evolution and Ecology
> University of California, Davis 95616
>
>
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>
>
>
>  --
> Max Soto
> C38 #198 ESTANCIA
> Puntarenas, Costa Rica
>
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>
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>
> --
> Donald R. Strong
> Professor
> Dept. of Evolution and Ecology
> University of California, Davis 95616
>
>   _______________________________________________
> Listserve mailing list
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>
>
> _______________________________________________
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>
>
> --
> Donald R. Strong
> Professor
> Dept. of Evolution and Ecology
> University of California, Davis 95616
>
>
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> Listserve mailing list
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>


-- 
Max Soto
C38 #198 ESTANCIA
Puntarenas, Costa Rica
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