Go Back  Offshoreonly.com > Technical > Do It Yourself, Boating on a Budget
Drilling and tapping stock exhaust >

Drilling and tapping stock exhaust

Notices

Drilling and tapping stock exhaust

Old 06-19-2020, 12:53 AM
  #1  
Registered
Thread Starter
 
Join Date: Apr 2015
Location: Arizona
Posts: 75
Likes: 0
Received 1 Like on 1 Post
Default Drilling and tapping stock exhaust

I want to convert my raisers to from the stock wet exhaust manifolds to a dry exhaust. Has anyone tried drilling and tapping the factory cast manifold to add a water transfer port?
KeatonAZ is offline  
Old 06-20-2020, 06:27 AM
  #2  
Registered
 
Join Date: Dec 2013
Location: Greenfield, Me.
Posts: 483
Received 21 Likes on 17 Posts
Default

Originally Posted by KeatonAZ
I want to convert my raisers to from the stock wet exhaust manifolds to a dry exhaust. Has anyone tried drilling and tapping the factory cast manifold to add a water transfer port?
Ayuh,..... You mean dry Joint,..??

I'd just swap the exhaust, 'n sell yer old ones,.....
Bondo is offline  
Old 06-22-2020, 08:23 AM
  #3  
Registered
 
Join Date: Mar 2019
Posts: 172
Received 65 Likes on 44 Posts
Default

There should be a pipe plug in the manifold near where the riser bolts on, see if you can get that out and thread a hose barb in. Whatever risers you put on will need to block the water jacket in the manifold.
You won't really see any performance gain from this but it will be louder, but might sound more like dump truck with no exhaust loud not race boat loud, because of the stock manifold design.
LakeHuronPower is offline  
Old 06-22-2020, 09:30 AM
  #4  
Registered
 
Join Date: Sep 2008
Posts: 460
Received 31 Likes on 22 Posts
Default

Originally Posted by LakeHuronPower
There should be a pipe plug in the manifold near where the riser bolts on, see if you can get that out and thread a hose barb in. Whatever risers you put on will need to block the water jacket in the manifold.
You won't really see any performance gain from this but it will be louder, but might sound more like dump truck with no exhaust loud not race boat loud, because of the stock manifold design.
omg lol. Dump truck loud... good one👍
oconnor marine is offline  
Old 06-22-2020, 01:35 PM
  #5  
Registered
Thread Starter
 
Join Date: Apr 2015
Location: Arizona
Posts: 75
Likes: 0
Received 1 Like on 1 Post
Default

What I'm talking about is replacing what is in the red box with something similar to the image in the left. water still has to transfer, so drilling and tapping where the blue dot is.


KeatonAZ is offline  
Old 06-23-2020, 08:14 AM
  #6  
Registered
 
Join Date: Mar 2019
Posts: 172
Received 65 Likes on 44 Posts
Default

Yeah that'll work fine. Is there not a pipe plug anywhere in the manifolds you have? Just saying if there is you don't need to drill or tap anything, just thread a hose barb fitting in.
LakeHuronPower is offline  
Old 06-23-2020, 12:42 PM
  #7  
Registered
Thread Starter
 
Join Date: Apr 2015
Location: Arizona
Posts: 75
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by LakeHuronPower
Yeah that'll work fine. Is there not a pipe plug anywhere in the manifolds you have? Just saying if there is you don't need to drill or tap anything, just thread a hose barb fitting in.
No there is no plug in the manifolds I have or I would have just opted to used them vs drilling and tapping. The overall attempt is to get a O2 sensor in the exhaust stream in a dry section
KeatonAZ is offline  
Old 06-24-2020, 12:09 AM
  #8  
Charter Member # 55
Charter Member
 
Griff's Avatar
 
Join Date: Oct 2000
Location: Omaha/LOTO
Posts: 19,516
Received 1,783 Likes on 884 Posts
Default

Imco is only one company that makes risers like you posted to bolt up to stock Merc cast manifolds and they use a wet joint.
What exactly are you trying to accomplish??
Griff is offline  
Old 06-24-2020, 08:26 AM
  #9  
Registered
 
Join Date: Mar 2019
Posts: 172
Received 65 Likes on 44 Posts
Default

Yeah that might be a problem...unless you are custom making a riser or something. If you're trying to save money I would just look for a used set of aftermarket manifolds, EMI, Stainless marine, etc. Save you a lot of work, and be lighter than factory cast iron.
LakeHuronPower is offline  
Old 06-24-2020, 09:23 AM
  #10  
rws
Registered
iTrader: (3)
 
rws's Avatar
 
Join Date: Jan 2001
Location: Toledo Ohio Eubank Ky
Posts: 621
Likes: 0
Received 1 Like on 1 Post
Default

I have adapted Gil riser's to small block Mercruiser manifolds, with home made adapter plates
so it can be done


rws is offline  

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.