Return to the home page...

Go Back   Moyer Marine Atomic 4 Community - Home of the Afourians > Discussion Topics > Exhaust System

Reply
 
Thread Tools Display Modes
  #1   IP: 174.94.17.146
Old 01-04-2011, 01:46 AM
67c&ccorv's Avatar
67c&ccorv 67c&ccorv is offline
Afourian MVP
 
Join Date: Dec 2008
Location: London, ON
Posts: 1,559
Thanks: 4
Thanked 9 Times in 9 Posts
Tartan S/S standpipe exhaust in C&C Corvette

Don,

Wondering about the feasibility of installing the MMI S/S Tartan standpipe exhaust in my 1967 C&C Corvette?

Instead of the exhaust exiting out of the side of the boat as on a Tartan it would run approximately 10ft on a slight upward slope to a gooseneck or loop and then down and out the rear transom.

The old copper-jacketed exhaust is a heavy behemoth and takes up a lot of space that I could put to better use.

Any thoughts?
Reply With Quote
  #2   IP: 38.118.55.125
Old 01-04-2011, 07:30 AM
Don Moyer's Avatar
Don Moyer Don Moyer is offline
 
Join Date: Oct 2004
Posts: 2,811
Thanks: 0
Thanked 183 Times in 124 Posts
I don't claim any engineering expertise in the dynamics of fluid flow through an enclosed system, but we do have considerable feedback from customers to indicate that anytime an exhaust hose goes through multiple peaks and valleys after it starts down from the high point just downstream of a water lift muffler or standpipe, exhaust back pressure will elevate somewhat with each peak. It appears that each peak and valley functions as an additional "water lift" device, and the elevation of back pressure seems to be accumulative between each such peak and valley.

In your particular application, the "slight" elevation in the hose between the standpipe and the transom might be tolerable, but I'd worry about the additional loop just before the exhaust exits.

Beyond this rudimentary understanding of the principles involved, it's very difficult to accurately calculate beforehand what amount of "peaking and valleying" any particular application will tolerate. But, relying again on considerable customer feedback, a reliable indicator of a properly functioning exhaust system (after the fact of a system change) is to observe the flow of engine cooling water leaving with the exhaust at your highest normal cruising power setting. The water should be seen to flow out evenly with the exhaust, not "batching" (stopping and starting) as is quite common at idle. If you note even a subtle stopping and starting of the water flow while cruising, some elevation of exhaust back pressure is no doubt taking place.

Don
Reply With Quote
  #3   IP: 98.248.12.160
Old 01-04-2011, 11:06 AM
tartansailboat tartansailboat is offline
Senior Member
 
Join Date: Mar 2009
Posts: 100
Thanks: 0
Thanked 2 Times in 2 Posts
Tartan S/S standpipe

I replaced my original copper standpipe in my Tartan 30 with Don's SS water lift muffler for about half the price of the SS Standpipe. Takes up a lot less room and works fine. There may be an advantage with the SS standpipe in that the water flow is less likely to back up into the engine if there is a starting problem but so far I have not seen that.
Reply With Quote
  #4   IP: 173.166.26.241
Old 01-04-2011, 12:39 PM
hanleyclifford's Avatar
hanleyclifford hanleyclifford is offline
Afourian MVP
 
Join Date: Mar 2010
Posts: 6,978
Thanks: 172
Thanked 280 Times in 226 Posts
Talking

67 - I remember how we thrashed this exhaust business around earlier and remember noting that the water jacketed system that you have is the most efficient practical alternative, from the engine's point of view. The standpipe concept is the second best but relies on the downhill flow from the standpipe - the essence of it's advantage over the waterlift concept which in my view is (the) last (practical) choice, but the one (unfortunately) that most of us are left with. As I said earlier, I would love to have the system you currently enjoy, but I can certainly understand if space considerations are great enough to override engine efficiency.
Reply With Quote
  #5   IP: 174.94.17.146
Old 01-04-2011, 10:08 PM
67c&ccorv's Avatar
67c&ccorv 67c&ccorv is offline
Afourian MVP
 
Join Date: Dec 2008
Location: London, ON
Posts: 1,559
Thanks: 4
Thanked 9 Times in 9 Posts
Quote:
Originally Posted by hanleyclifford View Post
67 - I remember how we thrashed this exhaust business around earlier and remember noting that the water jacketed system that you have is the most efficient practical alternative, from the engine's point of view. The standpipe concept is the second best but relies on the downhill flow from the standpipe - the essence of it's advantage over the waterlift concept which in my view is (the) last (practical) choice, but the one (unfortunately) that most of us are left with. As I said earlier, I would love to have the system you currently enjoy, but I can certainly understand if space considerations are great enough to override engine efficiency.
Agreed Hanley - the engine exhaust never has to push the water until it is injected into the very last section of the exhaust loop at the transom. The water injected into the copper jacket exhaust cools the exhaust without actually mixing with it.

It must be quite a load for the water pump but the system has worked well so far...it's just that the copper jacketed exhaust interferes with a number of systems (fuel tank, engine water intake etc.) and I would like to do away with it...maybe I will just go with the standard waterlift?

Thanks for your thoughts.

Cheers!
Reply With Quote
  #6   IP: 173.166.26.241
Old 01-04-2011, 10:57 PM
hanleyclifford's Avatar
hanleyclifford hanleyclifford is offline
Afourian MVP
 
Join Date: Mar 2010
Posts: 6,978
Thanks: 172
Thanked 280 Times in 226 Posts
Question

67 - I have been kicking this idea around in my head for a variation. How about a copper jacketed exhaust cooler exiting straight out of the engine, like yours, but shorter yet fat enough to cool the gases to the point where an ordinary exhaust hose could carry them up to the transom and out. The cooling water from the jacket could be discharged overboard at the most convenient location. What say ye?
Reply With Quote
  #7   IP: 174.94.17.146
Old 01-05-2011, 12:23 PM
67c&ccorv's Avatar
67c&ccorv 67c&ccorv is offline
Afourian MVP
 
Join Date: Dec 2008
Location: London, ON
Posts: 1,559
Thanks: 4
Thanked 9 Times in 9 Posts
I was actually thinking of going the opposite direction Hanley;

...making the water jacketed section longer and slimmer in diameter but still containing the same amount of water.

That might help with clearance issues and spread the weight of the waterjacketed section over a greater area.

When I drain the thing for winter layup a lot of water comes out of it!

Cheers!
Reply With Quote
  #8   IP: 24.152.131.220
Old 01-05-2011, 07:45 PM
ndutton's Avatar
ndutton ndutton is offline
Afourian MVP
 
Join Date: May 2009
Location: Torrance, CA
Posts: 9,619
Thanks: 198
Thanked 2,208 Times in 1,425 Posts
When researching a planned modification to the exhaust system, it might be a good idea to visit the USCG requirements on the subject to be sure your finished system complies.

Here is an excerpt that specifically addresses part of the discussion in this thread:
Quote:
46 CFR Ch. I (10–1–10 Edition)
§ 182.425


(1) Water for cooling the exhaust pipe must be obtained from the engine cooling water system or a separate engine driven pump.
(2) Water for cooling the exhaust pipe, other than a vertical exhaust, must be injected into the exhaust system as near to the engine manifold as practicable. The water must pass through the entire length of the exhaust pipe.
In item 2, I interpret "injected into the exhaust system" to include water jacketed exhausts as a "system."

Hope this is helpful.
__________________
Neil
1977 Catalina 30
San Pedro, California
prior boats 1987 Westsail 32, 1970 Catalina 22
Had my hands in a few others
Reply With Quote
  #9   IP: 173.166.26.241
Old 01-06-2011, 08:03 AM
hanleyclifford's Avatar
hanleyclifford hanleyclifford is offline
Afourian MVP
 
Join Date: Mar 2010
Posts: 6,978
Thanks: 172
Thanked 280 Times in 226 Posts
Smile

Good catch Neil. That appears to exclude my idea from the USCG point of view, though I'm sure I could make it work.
Reply With Quote
  #10   IP: 68.104.86.117
Old 01-06-2011, 11:24 AM
roadnsky's Avatar
roadnsky roadnsky is offline
Afourian MVP
 
Join Date: Dec 2008
Location: Lake Mead, NV
Posts: 3,104
Thanks: 24
Thanked 467 Times in 309 Posts
Quote:
Originally Posted by hanleyclifford View Post
Good catch Neil. That appears to exclude my idea from the USCG point of view, though I'm sure I could make it work.
Hanley-
Are you suggesting you'd be able to "bribe" a Coastie?!
Just kidding, just kidding...
__________________
-Jerry

'Lone Ranger'

1978 RANGER 30

Last edited by roadnsky; 01-06-2011 at 11:27 AM.
Reply With Quote
  #11   IP: 173.166.26.241
Old 01-06-2011, 12:55 PM
hanleyclifford's Avatar
hanleyclifford hanleyclifford is offline
Afourian MVP
 
Join Date: Mar 2010
Posts: 6,978
Thanks: 172
Thanked 280 Times in 226 Posts
The coasties are more interested in your "no discharge" plaque over the pottie.
Reply With Quote
  #12   IP: 138.88.75.40
Old 01-06-2011, 09:03 PM
sastanley's Avatar
sastanley sastanley is offline
Afourian MVP
 
Join Date: Sep 2008
Location: Solomons, MD
Posts: 7,016
Thanks: 1,134
Thanked 600 Times in 442 Posts
Quote:
Originally Posted by hanleyclifford View Post
The coasties are more interested in your "no discharge" plaque over the pottie.
Uh oh, is that where it's supposed to be? Do you think they'd bother to let me show them that the plumbing doesn't even route overboard?
__________________
-Shawn
"Holiday" - '89 Alura 35 #109
"Twice Around" - '77 C-30, #511 with original A-4 & MMI manifold - SOLD! (no longer a two boat owner!!)
http://www.moyermarine.com/forums/signaturepics/sigpic3231_6.gif
Reply With Quote
  #13   IP: 173.166.26.241
Old 01-06-2011, 11:51 PM
hanleyclifford's Avatar
hanleyclifford hanleyclifford is offline
Afourian MVP
 
Join Date: Mar 2010
Posts: 6,978
Thanks: 172
Thanked 280 Times in 226 Posts
Talking

I got a gig on this just outside of Deltaville once. The plaque has to be displayed in both head AND engine room.
Reply With Quote
  #14   IP: 173.10.248.102
Old 01-07-2011, 07:38 AM
sailbristol's Avatar
sailbristol sailbristol is offline
Senior Member
 
Join Date: Jan 2009
Location: Charleston,Sc
Posts: 137
Thanks: 0
Thanked 0 Times in 0 Posts
which one?

which plackard the oil or the garbage or the drug?
Reply With Quote
  #15   IP: 71.168.64.77
Old 01-07-2011, 08:28 AM
ArtJ ArtJ is offline
 
Join Date: Sep 2009
Posts: 2,177
Thanks: 221
Thanked 65 Times in 50 Posts
Smile

Quote:
Originally Posted by hanleyclifford View Post
I got a gig on this just outside of Deltaville once. The plaque has to be displayed in both head AND engine room.
Just a thought- Maybe the engine discharge should be a rubber hose laid
in the head bowl !!! Would save a plaque. ( only kidding)
Reply With Quote
  #16   IP: 173.166.26.241
Old 01-07-2011, 10:40 AM
hanleyclifford's Avatar
hanleyclifford hanleyclifford is offline
Afourian MVP
 
Join Date: Mar 2010
Posts: 6,978
Thanks: 172
Thanked 280 Times in 226 Posts
I like to use the plaque that covers everything - then you can post it anywhere and you're covered. There ought to be one on the poop deck for people who carry dogs on board!
Reply With Quote
  #17   IP: 71.168.64.77
Old 01-07-2011, 11:20 AM
ArtJ ArtJ is offline
 
Join Date: Sep 2009
Posts: 2,177
Thanks: 221
Thanked 65 Times in 50 Posts
Quote:
Originally Posted by hanleyclifford View Post
I like to use the plaque that covers everything - then you can post it anywhere and you're covered. There ought to be one on the poop deck for people who carry dogs on board!
I always wondered why there was a "poop" deck, now I know.
If only
the dogs obey and know their limits as Clint Eastwood says.
Reply With Quote
  #18   IP: 206.125.176.3
Old 01-07-2011, 01:56 PM
sastanley's Avatar
sastanley sastanley is offline
Afourian MVP
 
Join Date: Sep 2008
Location: Solomons, MD
Posts: 7,016
Thanks: 1,134
Thanked 600 Times in 442 Posts
Lightbulb

Art, actually, I think it is called a poop deck because you often get 'pooped' by a wave back there...those Europeans sure are silly!
__________________
-Shawn
"Holiday" - '89 Alura 35 #109
"Twice Around" - '77 C-30, #511 with original A-4 & MMI manifold - SOLD! (no longer a two boat owner!!)
http://www.moyermarine.com/forums/signaturepics/sigpic3231_6.gif
Reply With Quote
  #19   IP: 71.168.64.77
Old 01-07-2011, 02:39 PM
ArtJ ArtJ is offline
 
Join Date: Sep 2009
Posts: 2,177
Thanks: 221
Thanked 65 Times in 50 Posts
Smile

Shawn (appologies for hijacking thread) Maybe that explains why the
ordinary seaman's
facilities was at the bow sprit, maybe that
should have been called the Pee deck?
Reply With Quote
Reply

Thread Tools
Display Modes

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Tartan 30 Exhaust jacques debauche Tartan 8 07-02-2010 03:42 PM
Tartan 30 exhaust system rebuild jacques debauche Tartan 2 05-22-2010 06:48 AM
Tartan 34 exhaust replacement longhorizon Tartan 7 10-07-2009 08:09 AM
C&C 27 Exhaust design drafts rigspelt Exhaust System 7 05-18-2009 04:22 PM
Stuck #4 Exhaust Valve: A special Tartan 30 problem? jellisfeingold Tartan 7 12-09-2006 03:11 PM


All times are GMT -4. The time now is 04:13 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.


Universal® is a registered trademark of Westerbeke Corporation

Copyright © 2004-2024 Moyer Marine Inc.

All Rights Reserved