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

Mon Nov 7 11:13:39 EST 2011

Ya, mine is located after the exchanger too probably because there is
more flexibility in areas to locate it higher without having large hose
runs.   

From: listserve-bounces at catalina38.org
[mailto:listserve-bounces at catalina38.org] On Behalf Of Max Soto
Sent: Monday, November 07, 2011 7:37 AM
To: Catalina 38 Listserve
Subject: Re: [C38] Fwd: Re: Vented loop in cooling system

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%2
0drown.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> <mailto:drstrong at ucdavis.edu> 

To: 

Catalina 38 Listserve <listserve at catalina38.org>
<mailto: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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	-- 
	Donald R. Strong
	Professor
	Dept. of Evolution and Ecology
	University of California, Davis 95616

	_______________________________________________
	Listserve mailing list
	Listserve at catalina38.org
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_______________________________________________
Listserve mailing list
Listserve at catalina38.org
http://catalina38.org/mailman/listinfo/listserve_catalina38.org

-- 
Donald R. Strong
Professor
Dept. of Evolution and Ecology
University of California, Davis 95616

_______________________________________________
Listserve mailing list
Listserve at catalina38.org
http://catalina38.org/mailman/listinfo/listserve_catalina38.org

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

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