Boat Design Forums  |  Boat Design Directory  |  Boat Design Gallery  |  Boat Design Book Store  |  Thanks to Our Site Sponsors

Go Back   Boat Design Forums > Collaboration > Projects & Proposals
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 06-28-2009, 06:20 PM
Externet Externet is offline
Junior Member
 
Join Date: May 2009
Rep: 24 Posts: 22
Location: California
To insert a pipe in the exhaust manifold ?

Hello all.

For a small block GM V8, there may be many different types of wet exhaust manifolds, but sticking to whatever is typical stockish; how would you insert a straight 5/16"~3/8" stainless steel pipe lenghtwise into the hot gases chamber and exiting at both ends of the manifold ? (a pass-trough pipe)

Perhaps compression fittings on threaded holes at the ends ? Or some other suggestions and considerations ?

Yes, the hot gases would encounter a little restricted path because of the intrusion of such pipe in the chamber.

Is there a type of wet manifold that such contraption would not be advisable on ?

A crude 'ideal' drawing,
top and bottom "====" the double wall jacket;
centre "====" the inserted pipe;
"O" the head outlets;
"^^^" the flange to riser shown centered, but could be at one end.
Ignore the dots.

.....|==============|^^^|=============|
=====================================
.....|======O======= O O =======O======|

Miguel
Reply With Quote
  #2  
Old 06-28-2009, 08:28 PM
pistnbroke's Avatar
pistnbroke pistnbroke is offline
I try
 
Join Date: Jan 2009
Rep: 372 Posts: 1,230
Location: Noosa.Australia where god kissed the earth.
why do you want this ?? if its for hot water why not wrap copper pipe around the outside ? you could drill and braze /silver solder your thro pipe into place
Reply With Quote
  #3  
Old 06-28-2009, 09:35 PM
Frosty's Avatar
Frosty Frosty is online now
Senior Member
 
Join Date: May 2002
Rep: 1528 Posts: 5,519
Location: Thailand
I too am confused , what are you wanting to do?

If you want some hot water???? just hook in a heat exchanger in the cooling system.

Make one up --st/steel box --copper pipe. braze it in.

The exhaust is far too hot it will boil.
Reply With Quote
  #4  
Old 06-29-2009, 03:14 PM
gonzo's Avatar
gonzo gonzo is offline
Senior Member
 
Join Date: Aug 2002
Rep: 1397 Posts: 7,216
Location: Milwaukee, WI
Are you trying to run a pipe through two water jackets and the inside of the manifold? What for?
__________________
Gonzo
Reply With Quote
  #5  
Old 06-29-2009, 04:51 PM
Externet Externet is offline
Junior Member
 
Join Date: May 2009
Rep: 24 Posts: 22
Location: California
Trying to find a proper securing method for the pipe to be in the hot exhaust flow only, not trough water jackets.
Am reluctant to welding/brazing as the linear expansion of the pipe for a delta T of >~1000Fº could break welds.
Reply With Quote
  #6  
Old 06-29-2009, 09:50 PM
Frosty's Avatar
Frosty Frosty is online now
Senior Member
 
Join Date: May 2002
Rep: 1528 Posts: 5,519
Location: Thailand
Still dont know what you are trying to do???

Is this a water injection pipe.
Reply With Quote
  #7  
Old 06-29-2009, 10:53 PM
Externet Externet is offline
Junior Member
 
Join Date: May 2009
Rep: 24 Posts: 22
Location: California
Steam from seawater. To distill. For 'pennies'
I made fresh water supply on a tuna fishing boat too many years ago. It had a plain 'insulation wrapped' exhaust stack on Detroit Diesels 671, easier to tackle.
Trying to do it on a small yacht.
Miguel
Reply With Quote
  #8  
Old 06-30-2009, 03:27 PM
gonzo's Avatar
gonzo gonzo is offline
Senior Member
 
Join Date: Aug 2002
Rep: 1397 Posts: 7,216
Location: Milwaukee, WI
The exhaust manifolds have water jackets. There is no way around it.
__________________
Gonzo
Reply With Quote
  #9  
Old 06-30-2009, 06:51 PM
mydauphin mydauphin is offline
Senior Member
 
Join Date: Apr 2007
Rep: 472 Posts: 1,391
Location: Florida
You would have to build a custom exhaust manifold based on car engine manifold then use wet exhaust after that. Wrap exhaust manifold with copper tubing and trickle just enough salt water to generate right amount of steam and then send it somewhere to cool like keel cooler. I don't know if the extra heat in engine is worth the problem, also gas engine being run a large amount of hours to make water is not very efficient. That said the idea is not bad on a diesel with a section of dry exhaust, problem would be corrosion.
Reply With Quote
  #10  
Old 06-30-2009, 07:17 PM
pistnbroke's Avatar
pistnbroke pistnbroke is offline
I try
 
Join Date: Jan 2009
Rep: 372 Posts: 1,230
Location: Noosa.Australia where god kissed the earth.
you could put a 3 inch coupler after the manifold and feed the pipe in and up tpwards the engine then double back and out again ....BUT yes you can only have pure steam but where does the salt go ...it bungs up the pipe .like a kettle in a hard water area .......bad idea
Reply With Quote
  #11  
Old 06-30-2009, 11:15 PM
Externet Externet is offline
Junior Member
 
Join Date: May 2009
Rep: 24 Posts: 22
Location: California
As myself am not familiar with their construction, the question is which of these:

http://www.webspawner.com/users/hite...ifolds-lrg.jpg

http://www.cpperformance.com/images/421-PF-8.JPG

http://www.wholesalemarine.com/mm5/g...1953-2_med.jpg

http://www.tristband.com/ebay/sierra1983-1.jpg

or other common exhaust has no double wall water jacket at the ends, as that has to be the place to drill to insert the pipe lengthwise, kind of sketched on the initial post. Perhaps this one? :

http://www.sterndrive.info/sitebuild...-1968-1982.jpg

If none has a spot that a perforation will not cross on jacket water, I will have to come up with a more elaborated double walled fitting to bridge the jacket.

pistbroke: Yes, a curved pipe in the manifold is a bad idea.

mydauphin : it is not to run an engine to make water, it is to make water when the engine is running.

Miguel

Last edited by Externet : 06-30-2009 at 11:26 PM. Reason: Added link
Reply With Quote
  #12  
Old 07-01-2009, 01:04 AM
pistnbroke's Avatar
pistnbroke pistnbroke is offline
I try
 
Join Date: Jan 2009
Rep: 372 Posts: 1,230
Location: Noosa.Australia where god kissed the earth.
nothing wrong with the pipe going up the manifold and then bending 360 and comming out again
WHERE WILL THE SALT REMOVED IN THE BOILING END UP ????

BUNGING UP THE PIPE ...why do they use distilled water in a model steam train ???? think on it (_!_)

you will also have to pump the water in as 1cubic inch of water ( for you non metric yanks ) makes 22400 cu in of steam ( Avagadros number ) ...At NTP of course ....if the steam temp doubles you will get twice that volume ....
Reply With Quote
  #13  
Old 07-01-2009, 01:48 AM
Externet Externet is offline
Junior Member
 
Join Date: May 2009
Rep: 24 Posts: 22
Location: California
Hi.
There is many ways of doing it wrong, a non-straight pipe is one of them.

The "should be straight" pipe takes a "+" (cross) fitting at its flow exit end. The lower branch drains brine carrying the salt away, the top branch carries steam, a side branch is a plug, plus other details.

But you can make one with a 180, or 360 turn.

Miguel
Reply With Quote
  #14  
Old 07-01-2009, 03:23 AM
murdomack murdomack is offline
New Member
 
Join Date: Jun 2007
Rep: 262 Posts: 264
Location: Glasgow
Quote:
Originally Posted by mydauphin View Post
You would have to build a custom exhaust manifold based on car engine manifold then use wet exhaust after that. Wrap exhaust manifold with copper tubing and trickle just enough salt water to generate right amount of steam and then send it somewhere to cool like keel cooler. I don't know if the extra heat in engine is worth the problem, also gas engine being run a large amount of hours to make water is not very efficient. That said the idea is not bad on a diesel with a section of dry exhaust, problem would be corrosion.
Could you use sandwich flanges with the tubes in place at the head outlets? Would a leak be liable to run back into the engine once it was stopped?
Reply With Quote
  #15  
Old 07-01-2009, 10:15 AM
Frosty's Avatar
Frosty Frosty is online now
Senior Member
 
Join Date: May 2002
Rep: 1528 Posts: 5,519
Location: Thailand
What about a 12v kettle???
Reply With Quote
Reply



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Exhaust Manifold and Riser Cleaning MadMallard Gas Engines 2 09-14-2007 10:38 AM
how to insert point to a chine Ahmed Wahab Software 5 07-22-2007 03:46 PM
mold insert to deal with negative return corners?? Pavook Fiberglass and Composite Boat Building 4 11-28-2005 01:10 PM
Packajet exhaust manifold jetboatjill Open Discussion: All Things Boats & Boating 1 05-06-2005 10:40 AM
how do i insert images? joelhickey Open Discussion: All Things Boats & Boating 1 06-08-2004 05:28 AM


All times are GMT -5. The time now is 03:58 AM.


Powered by: vBulletin Copyright ©2000 - 2012, Jelsoft Enterprises Ltd.
Web Site Design and Content Copyright ©1999 - 2012 Boat Design Net