Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 10-02-2009, 15:51   #1
Registered User
 
Christian Van H's Avatar

Join Date: Oct 2008
Location: Princeton, NJ
Boat: Challenger Anacapa 42
Posts: 2,097
Images: 57
Exhaust Shut-off Valves

Hi All! I'm replacing my exhaust hose and fittings right now. All hose is 2 7/8". I have found hose, a 90 deg elbow, and the correct straight hose connectors, but I want to install a ball shut-off valve of some sort right inside the transom to close the system during heavy following seas. Any ideas about valves that wont break the bank? Thanks, Chris
__________________

__________________
www.anacapas.com

Here's to swimmin' with bowlegged women!
Christian Van H is offline   Reply With Quote
Old 10-02-2009, 16:36   #2
Registered User
 
r.furborough's Avatar

Join Date: Oct 2008
Location: Norfolk, VA
Boat: Freedom 32 (Hoyt)
Posts: 223
Why not just use a flapper on the exhaust outlet. That will help in a following sea and will not get overlooked or eventually not used.
__________________

__________________
------------------------------------------------
the memories of a man in his old age, are the dreams of a man in his prime
Pink Floyd - 'Free Four'
r.furborough is offline   Reply With Quote
Old 10-02-2009, 16:38   #3
Registered User
 
Christian Van H's Avatar

Join Date: Oct 2008
Location: Princeton, NJ
Boat: Challenger Anacapa 42
Posts: 2,097
Images: 57
I see your point, but I'm not sure it's enough protection. I understand what you mean about overlooked and not used though...
__________________
www.anacapas.com

Here's to swimmin' with bowlegged women!
Christian Van H is offline   Reply With Quote
Old 10-02-2009, 20:25   #4
Senior Cruiser
 
delmarrey's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Now in Blaine, WA
Boat: Modified Choate 40
Posts: 10,702
Images: 122
If your worried about following seas then you need to re-plumb your exhaust. Here are a few options.











__________________
Faithful are the Wounds of a Friend, but the Kisses of the Enemy are Deceitful! ........
A nation of sheep breeds a government of wolves!

Unprepared boaters, end up as floatsum!.......
delmarrey is offline   Reply With Quote
Old 10-02-2009, 20:53   #5
Registered User
 
Christian Van H's Avatar

Join Date: Oct 2008
Location: Princeton, NJ
Boat: Challenger Anacapa 42
Posts: 2,097
Images: 57
Wow Del, that was a lot of info. My boat uses a modified wet exhaust system unlike everything just posted, and has worked just fine for over 30 years. I just want the ability to shut off the system from following seas...something that Nigel Calder recommends, Anyone using a large valve out there?
__________________
www.anacapas.com

Here's to swimmin' with bowlegged women!
Christian Van H is offline   Reply With Quote
Old 10-02-2009, 22:03   #6
Senior Cruiser

Cruisers Forum Supporter

Join Date: Dec 2006
Location: Seattle
Boat: Cal 40
Posts: 2,401
Images: 7
Quote:
Originally Posted by Christian Van H View Post
Wow Del, that was a lot of info. My boat uses a modified wet exhaust system unlike everything just posted, and has worked just fine for over 30 years. I just want the ability to shut off the system from following seas...something that Nigel Calder recommends, Anyone using a large valve out there?

Both a friends Cal 34 I used to sail and the Cal40 I have now have a shutoff valve. I'm fairly sure I remember some of the other Cal 40s in the area have them as well. Came with the boat, so I have never priced one. My Cal 40 also has the flapper valve. I have only used the valve, other than exercising it, on the Cal 34 a few times. Once in the Straits of Georgia, and a couple of times on a Hawaii trip years ago.

John
__________________
cal40john is offline   Reply With Quote
Old 11-02-2009, 04:45   #7
CF Adviser
Moderator Emeritus
 
Hud3's Avatar

Cruisers Forum Supporter

Join Date: Sep 2007
Location: Virginia
Boat: Island Packet 380, now sold
Posts: 8,929
Images: 49
Christian,

I installed a flapper valve on the exhaust fitting after my first offshore passage. In following seas, I could hear the water running up the exhaust hose. It never got to the engine, but it worried me. The flapper valve solved the problem, completely. It slams shut when a wave hits it. Simple, cheap and foolproof! Emphasis on the foolproof.
__________________
Hud
Hud3 is offline   Reply With Quote
Old 11-02-2009, 06:08   #8
Registered User
 
Oceansandmts's Avatar

Join Date: Feb 2007
Location: Northern Vermont
Boat: "Piscator"
Posts: 87
Don't yet know how well it works, but the new boat has a Forespar 2" valve in the exhaust located in the high loop just before the transom. It is close to centerline and in the cockpit coaming, so I was able to arrange it so that the handle covers the on-off switch for the engine when the valve is closed. Since you have to open the valve to turn the engine on, there are no problems remembering to open the valve before starting!

A 3" valve is not going to be cheap, but it is probably like a lot of safety gear and arrangements: Probably never need it, hope you will never need it, but if the day ever does come you will really wish you had it.
__________________
John
Chuck Paine Sarah 32 under construction
Oceansandmts is offline   Reply With Quote
Old 11-02-2009, 07:31   #9
Registered User

Join Date: Nov 2005
Location: Ohio
Posts: 2,313
Well, we had a valve on the exhaust that was inadvertantly left closed when we started the engine, made a big bang when the muffler exploded. We now use a flapper and have a loop well above the waterline.
__________________
Joli is offline   Reply With Quote
Old 11-02-2009, 08:42   #10
Registered User

Join Date: Oct 2008
Posts: 218
We have a ball valve inline with the exhaust system on our 28 footer, with a Yanmar 3GMF. The valve is just before the transom exit. Marelon. Have not had any problems. It is just now needs some lubrication after ten years.

With goosenecks and waterlift mufflers, you need to watchout for excessive back pressure that setup might generate. Too much back pressure can cause a cylinder or two to go premtaurely. That happened on our Volvo MD7A
__________________
westsail42 is offline   Reply With Quote
Old 11-02-2009, 09:18   #11
Registered User
 
Sailorguy's Avatar

Join Date: Oct 2007
Location: Melbourne, Florida
Boat: Southern Cross 39 - sv Kristali
Posts: 51
I have a small diesel generator that is very sensitive to exhaust system back pressure...so in order to reduce it I eliminated the typical goose neck riser (near the stern exit)and inserted a plastic pvc ball valve between the lift muffler and the transom outlet, the valve is accessible from a cockpit locker. Purchased from Ace hardware, in-expensive and has held up well...Steve
__________________
Sailorguy is offline   Reply With Quote
Old 11-02-2009, 12:18   #12
Senior Cruiser
 
SkiprJohn's Avatar

Cruisers Forum Supporter

Join Date: May 2006
Location: Kea'au, Big Island, Hawaii
Boat: Cascade, Sloop, 42 - "Casual"
Posts: 14,192
Aloha Sailorguy,
I was thinking that since my Vetus muffler and gooseneck are made of plastic then why not the ball valve too?
You seem to have tried this with some luck.
My exhaust will exit on the port side. Not installed yet.
Kind regards,
JohnL
__________________
SkiprJohn is offline   Reply With Quote
Old 11-02-2009, 13:22   #13
Registered User

Join Date: Oct 2006
Location: The boat lives at Fidalgo Island, PNW
Boat: 36' custom steel
Posts: 992
Quote:
Originally Posted by Christian Van H View Post
My boat uses a modified wet exhaust system unlike everything just posted
My knowledge in this area is more than a little deficient. What is a modified wet exhaust?

And what is the normal system from which it is to be distinguished?

TIA.
__________________
John, sailing a custom 36' double-headed steel sloop--a 2001 derivation of a 1976 Ted Brewer design.
Hiracer is offline   Reply With Quote
Old 11-02-2009, 15:13   #14
Registered User
 
Christian Van H's Avatar

Join Date: Oct 2008
Location: Princeton, NJ
Boat: Challenger Anacapa 42
Posts: 2,097
Images: 57
Quote:
Originally Posted by Hiracer View Post
My knowledge in this area is more than a little deficient. What is a modified wet exhaust?
I cant find a diagram on the 'net, and my manual is down on the boat, but basically there is a SS muffler mounted ABOVE the manifold. Raw water is injected into this muffler and both gases and water exit the bottom and flow "downhill" and out the stern. It's extremely reliable with very low backpressure. Sorry I cant do better right now...
__________________
www.anacapas.com

Here's to swimmin' with bowlegged women!
Christian Van H is offline   Reply With Quote
Old 11-02-2009, 16:58   #15
Registered User

Join Date: Feb 2008
Location: Jacksonville FL
Boat: CSY 44' Grace
Posts: 46
Images: 1
Hang the boat keys on the shut off valve handle when you turn it off. That way you can't turn on the boat without at least seeing the valve.

I do this with my intake through hull when I turn it off. It has saved me many a times.
__________________

__________________
I tried having a bad day once - I did not like it.
peterroach is offline   Reply With Quote
Reply

Tags
exhaust

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Westerbeke Doesn't Shut Off with Key pacmaann2 Engines and Propulsion Systems 19 12-08-2009 19:15
Yanmar 4JHTE Won't Shut Down 6string Engines and Propulsion Systems 14 19-05-2009 16:08
How Does this Engine Shut Down? sailorboy1 The Sailor's Confessional 10 17-02-2009 20:45
Stainless steel valves or Marelon valves? David M Construction, Maintenance & Refit 11 10-12-2008 02:28
PDQ operations shut down for now? scotte Multihull Sailboats 16 26-03-2008 09:35



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 21:15.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.