Best option for quieting loud thru hull exhaust

alamantia

Petty Officer 2nd Class
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Dec 16, 2011
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133
My first boat had thru prop and I liked it. I stumbled on a great deal for a 1988 chris craft 245 limited with a 454 and thru hull. I took it out yesterday for the first time. I like the thru hull, but off plane, trolling around, it was difficult to maintain a conversation with my passengers over the rumbling. I also don't want to be that azzhole on the lake making noise. I wish it had captains call, but it only has straight thru hull with the black flappers under the swim platform and it was still too loud.

A quick search on here I saw a few older posts where someone recommended the corsa silencing tips and I found some KnB in-line mufflers with a google search that I guess you stuff in the rubber hoses.


has anyone on here had any personal experience with either expensive tips or in-line mufflers that wouldn't mind offering up some advice?

Thanks
 

hostage

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May 4, 2010
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1,291
Thank you for your consideration. I am not a fan of noise pollution. I know PT Boats during world war two used external exhausts to damper the sound:

Photo_Scan_PT_109_Ferried_Mufflers.jpg
 

alamantia

Petty Officer 2nd Class
Joined
Dec 16, 2011
Messages
133
Thank you for your consideration. I am not a fan of noise pollution. I know PT Boats during world war two used external exhausts to damper the sound:

Photo_Scan_PT_109_Ferried_Mufflers.jpg

Are you suggesting that I try to locate mufflers off a 1943 Higgins?
 

Suprathepeg

Petty Officer 1st Class
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May 25, 2015
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I was thinking about this last night, swapping out to a V8 and running the exhaust thru hull. I wonder if installing a stainless steel resonator after the manifolds and just having the tips go through the hull would be a bad idea? That would take a lot of the higher frequency out of it and knock the sound down but still have a nice rumble. Even a short glass pack could sound nice. Plus they're cheap.
 

smokeonthewater

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Dec 3, 2009
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Would I have to buy a Y-pipe and pull the motor to install it?

That depends on IF it still has a Y pipe in it...

If it doesn't have one pulling the engine is much easier than most folks expect if you have a way to lift it. Also used Y pipes are fairly plentiful on ebay and craigslist.

I've scrapped several and the one I had to buy cost me $75

Re: the last poster, you cannot use automotive exhaust components on a water cooled exhaust.
 

thumpar

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Jun 21, 2007
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There are mufflers you can buy. They look like a can. It would probably take some work to get them hooked up but would really quiet it down.
 

alamantia

Petty Officer 2nd Class
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Dec 16, 2011
Messages
133
I was looking at the corsa but I don't know where to buy them, I did not find a lot of options on line. The corsa's look great on their website but they don't sell to me. I would need to find an online store or dealer I guess. My fear is that I invest a bunch of money and time and they don't meet my expectation. I am hoping someone has installed mufflers in their thru hull to quiet their boat down and can make a suggestion based on their experience.
 

rallyart

Lieutenant Junior Grade
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Jun 7, 2008
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1,176
You will lose no power going through the prop. It might run better.
If you can't reconvert it with a Y pipe you could get freshairexhaust.com to make you up a system for your boat. They make an extremely good product for inboards and do quite a bit of custom work.
I'm sure it would be easier to find a way to reconnect the prop exhaust though.
 

roffey

Commander
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Nov 22, 2012
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2,190
How much power would you loose going to a prop exhaust?

prop exhaust is the same as through hull with the exception the water muffles the sound, start your boat out of the water, with water muffs on and hear it rumble. As usual feel free to correct me.
 
Last edited:

tpenfield

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Jul 18, 2011
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It will cost a bit of $$$$, but go with the silencing tips . . . Corsa "Quick & Quiet" or similar. 454 engines do not breath all that well through the prop, so thru-hull is not a bad thing for that size engine, it is just the noise that needs a solution.
 

oldjeep

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May 17, 2010
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Easiest solution would be to remove the flappers and install a silent tip exhaust downturns. Not as quiet as through prop, but a lot quieter than straight out.
 

smokeonthewater

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Dec 3, 2009
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A stock 454 will "breathe" absolutely fine through prop... Now get the power up around say 600 hp and it might be a bit restrictive.
 

Bondo

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I am hoping someone has installed mufflers in their thru hull to quiet their boat down and can make a suggestion based on their experience.
Ayuh,..... It can be nearly dead silent so long as the tips are underwater,.....

90? chrome elbows on yer tips, dumpin' just above the hull line, on plane,....

It'll still Roar on plane, but nice 'n Quiet at displacement speed,...

Kinda like Chrome PT boat mufflers,....
 
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