Manifolds (Trying to figure out what I am looking at)

Pmt133

Chief Petty Officer
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Jan 6, 2022
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So today since it was calm, I threw 2 people in the back of the boat and measured the static height per mercruiser. I get ~11.5 inches. If we move to normal seating positions it climbs to ~13 inches. So it looks like I will throw in a set of 3 inch risers to play it safe. After measuring I don't think I have room to go much taller so that should get me okay. I'll measure more tomorrow.
 

Pmt133

Chief Petty Officer
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Jan 6, 2022
Messages
527
I was thinking about that. Problem is I have wet joint so my options are 3" or 6" unless I missed something. Problem with that is at 6" I'm pretty sure I won't clear the rear part of the deck. I'll try and measure it tomorrow and get a better idea.
 

tpenfield

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The 3" should do the trick. I had to do the same on my Formula 330, when I added the extended swim platform.
 

Pmt133

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Jan 6, 2022
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Yeah. So no shot 6 inches would clear the transom without cutting. Or modifying the do house or any other slew of things for that matter. I'm going to dig around and see if anyone offers a 4 inch. That's about all she can take.
 

Scott06

Admiral
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Apr 20, 2014
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Yeah. So no shot 6 inches would clear the transom without cutting. Or modifying the do house or any other slew of things for that matter. I'm going to dig around and see if anyone offers a 4 inch. That's about all she can take.
I put this 1" plate in to put a O2 sensor for a Air fuel ratio meter could add that to the 3" . Also wonder of the 3 or 6" could be milled down. 6" milled to 4 " or 3" milled to 2" and used with another 3"
 

Pmt133

Chief Petty Officer
Joined
Jan 6, 2022
Messages
527
I put this 1" plate in to put a O2 sensor for a Air fuel ratio meter could add that to the 3" . Also wonder of the 3 or 6" could be milled down. 6" milled to 4 " or 3" milled to 2" and used with another 3"
I could mill a 3" but that seems like just introducing another potential leak on the wet joint... I'm thinking maybe next go around I convert to a dry joint setup which will give me more customization. The other issue then becomes getting the elbow tube to meet the y-pipe. I'd have to find some oddball exhaust tubing I'm sure if I were to have a 4" that isn't a stock configuration... the dry joint is tempting.

Also... In measuring last night I more accurately got a height as I used someone equal in weight to my fat azz. That plus some dumb weights put 750 extra pounds right on the transom and I got exactly 12 inches per how merc wants it measured. That puts me at 15 with the 3". I think that's enough cushion for now. I also remeasured with a full tank of fuel instead of half so the CG was pushed forward a bit.
 
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