[C320-list] Engine vented loop problem

[Dave Ouimette]

Rick,
 
Thanks. I have spoken to the factory about the vented loop and wasn't able to get clear information from them. However, I may have figured out the problem. I spoke again to Groco tech support and then was able to more carefully assemble the valve in the vented loop. I did a sea trial this afternoon and it appears the leak has stopped.  So much for my theory on aqua lift back pressure...it apparently doesn't hold water, so to speak.
 
Dave
Hull 174
 
 
-----Original Message-----
From: Rick Sulewski <rsulewski at bex.net>
To: C320-List <C320-List at Catalina320.com>
Sent: Mon, Jan 25, 2016 4:19 pm
Subject: Re: [C320-list] Engine vented loop problem

Dave,
 It just occurred to me that perhaps the shorter length of the hoses leading to valve with the loop in the engine compartment in your hull vs. having the loop valve in the port locker with several feet of hoses up and back, may result in increased direct water pressure from your exhaust  system vs. having more air traveling along the lengthier hoses in the port locker...... You may want to consider contacting technical assistance at Catalina and learn why the later model hulls such as my #277 had a different location than your hull #.
Rick

-----Original Message-----
From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Dave Ouimette
Sent: Monday, January 25, 2016 4:12 PM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] Engine vented loop problem


Rick,
 
Thanks for the info on your raw water vented loop.
 
Dave
Hull 174
 
 
 
-----Original Message-----
From: Rick Sulewski <rsulewski at bex.net>
To: C320-List <C320-List at Catalina320.com>
Sent: Mon, Jan 25, 2016 9:49 am
Subject: Re: [C320-list] Engine vented loop problem

Dave,
 My vented loop in hull #277 for my Westerbeke is located high in port locker and looks like the loop valve at Catalina Direct;  Anti Siphon Valve 3/4", Part #: Z3381 for $32.95. No problems with leaks after 20 seasons.
Rick 

-----Original Message-----
From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Dave Ouimette
Sent: Sunday, January 24, 2016 2:50 PM
To: C320-List at Catalina320.com
Subject: [C320-list] Engine vented loop problem



I have a 1995 C320 with a Perkins M30 engine. The boat originally came with a raw water vented loop installed inside the engine compartment. It was removed by a prior owner. Why, I don't know. I sought advice from the forum and decided to install a Groco HVL 3/4 inch bronze vented loop in the original engine compartment location. It has not worked well, that is, it dribbles water out the top opening. I spoke to Groco tech support and they told me this was a rare occurrence and not normal. They shipped a new valve insert which was subsequently installed. It leaks just as much. Groco valves are not the standard duck bill design but rather, circular neoprene-type rubber. Here is a link if you would like to look at the Groco design.

http://www.groco.net/sanitation.htm
 
The amount of the leak is not huge but hard to estimate because water drops in the pan beneath the engine and overflows into the opening where electric cables pass through to the starter, eventually making its way to the bilge. Regardless of quantity, the leak is not acceptable to me and I'm thinking of replacing the Groco with a Forespar with duck bill valve.
 
Some thoughts: the Groco vented loop is a one-way device, meaning, water must move in one direction only for it to work properly. This raises the question is it possible the leak I have is a result of back pressure from the aqua-lift muffler either during engine operation or, more likely, at shutdown when the valve in the vented loop relaxes and water in the exhaust hose might move backwards and out the top of the vent. Anyone want to weigh in on this theory?
 
Has anyone installed a Groco vent in their boat and had success with it? If so, I would like to hear from you.
 
Thanks.
Dave
Hull 174