Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 13-11-2023, 20:19   #1
Registered User
 
mbowser's Avatar

Join Date: Aug 2012
Boat: Niagara 35
Posts: 43
Removing threaded exhaust from manifold

I've started a rattle can rebuild on a Westerbeke W27 and I'm blocking off the winter to get this thing back in shape. The engine is out of the boat and sitting in my shop and the first order of business is to rebuild the exhaust manifold. Really the only thing that needs to be done is to replace the gaskets on either end, clean it up and repaint, but in order to do so I have to get the old exhaust pipe off that goes to the mixing elbow. I'm guessing it's galvanized steel and it's screwed into the aluminum manifold (I think it's aluminum). It's really badly rusted and of course it won't budge. I applied a bunch of PB Blaster and will keep at it for a few days, but I'm not confident it will free up.

Anyone have any tricks that I can use to get this free? Heat, hammer, bring it to a shop and throw money at it?
Attached Thumbnails
Click image for larger version

Name:	Capture.JPG
Views:	87
Size:	139.2 KB
ID:	283361  
__________________
Refitting Velorum: https://www.niagara35.com
Restoring Magic: https://www.alberg35.com
mbowser is offline   Reply With Quote
Old 13-11-2023, 20:48   #2
Registered User
 
deblen's Avatar

Join Date: Oct 2014
Location: Bay of Fundy,Grand Manan,N.B.,Canada N44.40 W66.50
Boat: Mascot 28 pilothouse motorsailer 28ft
Posts: 3,076
Images: 1
Re: Removing threaded exhaust from manifold

Since you have the engine out and in a warm workplace,plus lots of time-
Why not replace the old iron pipe with new black iron pipe & new black fittings. (Galv. just "burns" off under dry exhaust heat)
That means you only have to salvage the alum. manifold end plate.
or,if that plate is really as flat as it looks in pic,it may be easier to build a replacement for it also,using 5 or 6000 series marine alum. plate.
Cheers/Len
__________________
My personal experience & humble opinions-feel free to ignore both
.
deblen is offline   Reply With Quote
Old 13-11-2023, 21:25   #3
Registered User

Join Date: Aug 2021
Location: PNW
Boat: 35 Ft. cutter, custom
Posts: 1,859
Re: Removing threaded exhaust from manifold

Quote:
Originally Posted by deblen View Post
it may be easier to build a replacement for it also,using 5 or 6000 series marine alum. plate.
Cheers/Len
I think you're right, a new piece of plate would be of minimal cost.
Perhaps a bit thicker if stud length will allow?
OP, be careful with those studs that hold the end plate.
If they will easily come out and could be changed that would be great but take no chances at all of breakage or damage.
Perhaps just better to clean the threads with a wire brush, maybe run a die over them.
I mention that as you want the nuts, (new,) to easily tighten to make a leak proof joint without straining/risking the studs.
Use a good anti-seize paste on all threads, (Permatex).
__________________
Beginning to Prepare to Commence
Bowdrie is offline   Reply With Quote
Old 14-11-2023, 05:27   #4
Registered User
 
mbowser's Avatar

Join Date: Aug 2012
Boat: Niagara 35
Posts: 43
Re: Removing threaded exhaust from manifold

I think that picture might be misleading. The plate is just a cover for the coolant 'jacket' on the manifold. The pipe doesn't screw into the aluminum plate (that would be too easy), it is screwed into the extruded aluminum manifold body (underneath the plate) and it is corroded in good. I'm hoping I can get it out without destroying the manifold. I don't think this model manifold is made any more, so I want to be careful in my approach.
Attached Thumbnails
Click image for larger version

Name:	Capture.JPG
Views:	40
Size:	52.3 KB
ID:	283367  
__________________
Refitting Velorum: https://www.niagara35.com
Restoring Magic: https://www.alberg35.com
mbowser is offline   Reply With Quote
Old 14-11-2023, 08:45   #5
Registered User
 
deblen's Avatar

Join Date: Oct 2014
Location: Bay of Fundy,Grand Manan,N.B.,Canada N44.40 W66.50
Boat: Mascot 28 pilothouse motorsailer 28ft
Posts: 3,076
Images: 1
Re: Removing threaded exhaust from manifold

Quote:
Originally Posted by mbowser View Post
I think that picture might be misleading. The plate is just a cover for the coolant 'jacket' on the manifold. The pipe doesn't screw into the aluminum plate (that would be too easy), it is screwed into the extruded aluminum manifold body (underneath the plate) and it is corroded in good. I'm hoping I can get it out without destroying the manifold. I don't think this model manifold is made any more, so I want to be careful in my approach.

A pic is worth a thousand words indeed!
You may have to hacksaw the exhaust pipe off close to manifold end.
Then,use a mini hacksaw to slice the remaining threaded pipe stub lengthwise internally.That should let you collapse the old pipe,inside the manifold thread,with a cold chisel.


https://www.amazon.com/LENOX-Tools-M...9976818&sr=8-2


I have never used Permatex anti sieze,but I have had success with NeverSieze
https://neverseizeproducts.com/marin...-8-never-seez/
__________________
My personal experience & humble opinions-feel free to ignore both
.
deblen is offline   Reply With Quote
Old 14-11-2023, 09:16   #6
Registered User

Join Date: Jan 2008
Location: SF Bay Area (Boat Sold)
Boat: Former owner of a Valiant V40
Posts: 1,118
Re: Removing threaded exhaust from manifold

Looking at the pic, I might suggest (as a first step) removing the nipple, leaving the 45 street ell on the manifold. You can then inspect the inside of the 45. If it is in good enough condition, you could leave it in place rather than risk the manifold. Then rattle can the heck out of it.
jamhass is offline   Reply With Quote
Old 14-11-2023, 09:26   #7
Registered User
 
mbowser's Avatar

Join Date: Aug 2012
Boat: Niagara 35
Posts: 43
Re: Removing threaded exhaust from manifold

Quote:
Originally Posted by deblen View Post
A pic is worth a thousand words indeed!
You may have to hacksaw the exhaust pipe off close to manifold end.
Then,use a mini hacksaw to slice the remaining threaded pipe stub lengthwise internally.That should let you collapse the old pipe,inside the manifold thread,with a cold chisel.


https://www.amazon.com/LENOX-Tools-M...9976818&sr=8-2


I have never used Permatex anti sieze,but I have had success with NeverSieze
https://neverseizeproducts.com/marin...-8-never-seez/
I'm afraid that that is the way I'm going to have to go if I want to get the whole thing out, but it seems pretty risky and I'm afraid that using a cold chisel to collapse the pipe could crack the aluminum manifold. I've been alternating heat and pb blaster for the past 2 days and it's still not even close to budging. I'm going to give it another day or so to see if the pb blaster works its way into the joint.
__________________
Refitting Velorum: https://www.niagara35.com
Restoring Magic: https://www.alberg35.com
mbowser is offline   Reply With Quote
Old 14-11-2023, 09:32   #8
Registered User
 
mbowser's Avatar

Join Date: Aug 2012
Boat: Niagara 35
Posts: 43
Re: Removing threaded exhaust from manifold

Quote:
Originally Posted by jamhass View Post
Looking at the pic, I might suggest (as a first step) removing the nipple, leaving the 45 street ell on the manifold. You can then inspect the inside of the 45. If it is in good enough condition, you could leave it in place rather than risk the manifold. Then rattle can the heck out of it.
This is probably the safest route, the 45 degree elbow appears to be in decent shape. I'd really like to get in there to inspect/replace the baffles though.

I wonder if a machine shop with precision equipment would be able to tackle something like this?
__________________
Refitting Velorum: https://www.niagara35.com
Restoring Magic: https://www.alberg35.com
mbowser is offline   Reply With Quote
Old 14-11-2023, 09:35   #9
running down a dream
 
gonesail's Avatar

Join Date: Mar 2006
Location: FLORIDA
Boat: cape dory 30 MKII
Posts: 3,038
Images: 7
Send a message via Yahoo to gonesail
Re: Removing threaded exhaust from manifold

the hacksaw idea might be worth a try. maybe not the collapsing part .. a few cuts might help to release it .. but also could destroy the threads on the manifold
__________________
some of the best times of my life were spent on a boat. it just took a long time to realize it.
gonesail is offline   Reply With Quote
Old 14-11-2023, 10:18   #10
Registered User

Join Date: Aug 2021
Location: PNW
Boat: 35 Ft. cutter, custom
Posts: 1,859
Re: Removing threaded exhaust from manifold

Quote:
Originally Posted by gonesail View Post
the hacksaw idea might be worth a try. maybe not the collapsing part .. a few cuts might help to release it .. but also could destroy the threads on the manifold
Yes, requires steady hands and the patience of Job, one slip and ruined threads.
Might a shop that does Electro Discharge Machining achieve success?
A couple of times I've used a battery and jumper cables to break the bond of bolts that were frozen, but they were small sized and threaded into a relatively thin aluminum mast.
It's a process that's fraught with its own dangers, (you hope the battery doesn't explode).
__________________
Beginning to Prepare to Commence
Bowdrie is offline   Reply With Quote
Old 14-11-2023, 10:35   #11
Registered User
 
Madehn's Avatar

Join Date: Nov 2014
Location: Kemah Tx
Boat: Gulfstar 51
Posts: 593
Re: Removing threaded exhaust from manifold

Get it where you can put a pipe wrench on the nipple with the body in a vice. Heat up the aluminum while you hold some ice on the pipe. T
Put a little pressure on the pipe wrench then hit the end of the pipe wrench with an air chisel in the direction you want to turn. The rapid shocks will help to break it loose. If you can avoid taking it off do so. Sometimes perfect is the enemy of good enough. Good luck.
Madehn is offline   Reply With Quote
Old 14-11-2023, 11:11   #12
Registered User

Join Date: Mar 2016
Location: North of San Francisco, Bodega Bay
Boat: 44' Custom Aluminum Cutter, & Pearson 30
Posts: 548
Re: Removing threaded exhaust from manifold

If you cannot live with leaving the elbow. I think the best would be to leave it to a machine shop. But even they might mess it up. Do you have enough room to bump up one pipe size in the aluminum?
NorthCoastJoe is offline   Reply With Quote
Old 14-11-2023, 11:17   #13
Registered User

Join Date: Aug 2015
Location: Savannah Ga USA
Boat: Brewer 12.3
Posts: 153
Re: Removing threaded exhaust from manifold

Al expands 3 times as much as steel, Try heating the housing with a butane torch.
Bottom line this is a bad mix of materials.
Cutting it out I would use a dremel with a carbide bit. Hack saw is hard to control. Slow and carefully.
Consider replacing with Al pipe
Oldwheels is offline   Reply With Quote
Old 14-11-2023, 11:38   #14
Registered User

Join Date: Nov 2018
Location: Panama
Boat: Norseman 447
Posts: 1,605
Re: Removing threaded exhaust from manifold

I have the same exhaust manifold on my Genset. I constantly had problems with the end plates leaking because of the gasket between the aluminum manifold and the steel end plate. In 2005, I rebuilt the Genset and replaced the OEM steel end plates with ones made of 1/4” 6061 aluminum. They’re still there, no leaks since.
Bycrick is offline   Reply With Quote
Old 14-11-2023, 11:45   #15
Registered User

Join Date: Aug 2015
Location: States - Northeast
Boat: '86 MacGregor 25
Posts: 482
Re: Removing threaded exhaust from manifold

Quote:
Originally Posted by mbowser View Post
I'm afraid that that is the way I'm going to have to go if I want to get the whole thing out, but it seems pretty risky and I'm afraid that using a cold chisel to collapse the pipe could crack the aluminum manifold. Ö
Leave a little bit of pipe, donít cut it totally flush with the manifold. Cut 2 slits maybe 30 deg apart, then hammer inward on the exposed lip between them. Donít try to use the chisel as a wedge between the iron and aluminum.

Once the strip between the slots is bent in and removed, the rest will likely unthread. If not, just keep taking out strips.

This worked for me on a flange that bolts to the engine header manifold. It was steel, not aluminum though.
wyb2 is offline   Reply With Quote
Reply

Tags
exhaust

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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
Can you use mr. Gasket exhaust rated gasket paper for exhaust manifold, yanmar rkarakai21 Engines and Propulsion Systems 5 04-03-2023 19:58
Threaded exhaust sealant BigAl.NZ Engines and Propulsion Systems 6 01-02-2021 10:24
Re-attaching Exhaust Manifold sneuman Construction, Maintenance & Refit 6 01-07-2009 07:39
Wanted Perkins 4236 Exhaust Manifold Finner Classifieds Archive 4 01-07-2009 06:53

Advertise Here


All times are GMT -7. The time now is 02:57.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2023, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2023, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.