Thru-hull exhaust time!!!!

[thegoat86]

(audible Grunting) Me want loud boat!!!!! (audible grunting)

Seriously, looking for a good exhaust setup for my boat. 7.4MPI mercruiser. 2001. I need some decent tips with flappers. Looks like I have 4" out of the manifold. I Picked spots above the water line for the tips to exit. Should look really nice. Advice needed.

 

[thegoat86]

Looking to put them below the rub rail in the tan striped area on both sides.

 

[alldodge]

Several out there, just need to decide what the end result your looking for.
Do you want straight tips, muffler tips, silent choice (captains call)?
Then going to need to measure and get a 4 1/8 hole saw and a good drill

 

[thegoat86]

Great hearing from you again AD. The DTR forums kinda drying up a bit. Anyways, yes straight out. no need as I don't go to marinas anymore. No sound ordinances on the river as I can see. Lots of airboats out here. I just want this 7.4 to sound healthy. I am going to repower as soon as this MPI fails. I got a line on a 7.4 block and heads from an old southwind RV with 15k miles on it. Gonna pull it this summer. Then trick it out. So for now, I want to hear this 7.4 until it dies. I know the salt water played havoc on the block and seals. So its just a matter of time. Anyways, I love the tips in the IBOAT shop. They only come in 3" though. I really dont want a tip with an external flapper, and I dont want it sticking out beyond the boat too much. Kids like to jump into the water off the back. Any leads?

 

[Scott Danforth]

Stainless Marine or CMI or CP performance or EMI or Hardin all have tips with internal flappers.

I would suggest a complete captains call / silent choice (or other selectable exhaust name) as listening to the exhaust gets tiring after a while. you may want it now, you will soon not want it.

as for your motor, get a Gen IV block, build a 496 stroker with new crank/rods/pistons and look at Merlin heads or other as your currently limited with the L29 heads.

if you want more power than that, go with a 508 block, build a 540 stroker and put on a different drive

 

[QBhoy]

I have the full Corsa Marine system with side exits. Captains call too. The captains call as far as I know is coined by Corsa marine. It isn’t cheap. I think my system just to buy the kit is around $5000 last I looked. You’ll probably want the ability to switch it to silent at some point. If I couldn’t do that, I wouldn’t be able to look the neighbors in the marina straight in the face after a late night return. Even switched off, some exhaust still exits the hull exit ports. Not particularly silent but much quieter. Other than that, lovely noise. I gain about 50-100 rpm at most with them open. It actually draws power from the engine via the alternator to keep power to the large solonoids that keep the flaps open.

 

[alldodge]

Came down with the flu, yuk

I really dont want a tip with an external flapper, and I dont want it sticking out beyond the boat too much. Kids like to jump into the water off the back. Any leads?

There are flush mount tips with internal flappers
https://www.hardin-marine.com/p-1259...haust-tip.aspx

Or the straight tips
https://www.hardin-marine.com/c-466-...-cut-tips.aspx

You do want some kind flappers even if its a internal baffle to reduce reversion. May also need to change the elbow to direct toward the transom. Depending on how high the elbow is, may add a riser extension