Through Hull Exhaust

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jryotas

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Just picked up an 05 Larson with a Mercruiser 5.0 . Wanting to change over to through hull exhaust and have some questions . Looks like all I have to do is unbolt the tube that goes from the risers to the y pipe and block off the y pipe . Then drill some holes in the transom and connect the new fittings . What im wondering though is about the distance between the risers and the new exhaust tips that will be mounted in the transom . It will be about a foot between this connection . Is there some kind of high heat tubing I can run between here or will I need a splice piece of stainless ?
 

81 Checkmate

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Question – Have you ever been in boat with thru hull exhaust?

Black rubber exhaust tubing….you can buy it at the same place you get the tips.
BTW – Your fellow boaters at the lake are not going to like you all that much.
 

Franzel311

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I like load my self to but it's one thing to b load at 2pm and another at 7am ppl will thro rocks at you/ you should consider a diverter kit Coarsa makes a good one but pricy iv seen kits on eBay or parts to make your own kit in the range of 500 to 800
 

Franzel311

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And some marinas around me anyway won't even let you launch your boat anymore if the pipes r to load
 

alldodge

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Just picked up an 05 Larson with a Mercruiser 5.0 . Wanting to change over to through hull exhaust and have some questions . Looks like all I have to do is unbolt the tube that goes from the risers to the y pipe and block off the y pipe . Then drill some holes in the transom and connect the new fittings . What im wondering though is about the distance between the risers and the new exhaust tips that will be mounted in the transom . It will be about a foot between this connection . Is there some kind of high heat tubing I can run between here or will I need a splice piece of stainless ?

The current exhaust tube used by all boats will handle the heat, no issue. Your going to need to seal up your Y-pipe real good or you can get a leak. Corsa or Captains call is the best way to go. In installed diverters in my cruiser.

Reality check, your installing thru hull just because you want it to sound loud, not that it will make any negligible difference with your 5.0L. If you had a big block I can see why, so enjoy the noise and if you get a ticket remember to think it was worth it, because you like it loud :rolleyes:
 
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jryotas

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Really dont wanna spend the cash for captains call but I am going to run internal silencers . I want a little sound but not obnoxiously loud , plus obviously want the performance gain . The only lake we are on is full of Bajas and big go fast boats so everyone there is use to the noise . Its either loud exhaust or loud stereos .
Thank You everyone for the replies
 

Scott Danforth

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welcome aboard

you would get more performance gain by loosing 20# of weight and waxing your hull than you will with a 5.0 and thru-hull.

you dont have enough motor for a thru-hull to make a difference. Its good for about 10hp on a built 350. that equated to about 1mph.

however its your money spend it any way you want.
 

Bondo

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Really dont wanna spend the cash for captains call but I am going to run internal silencers . I want a little sound but not obnoxiously loud , plus obviously want the performance gain . The only lake we are on is full of Bajas and big go fast boats so everyone there is use to the noise . Its either loud exhaust or loud stereos .
Thank You everyone for the replies

Ayuh,.... There is 0, Zero performance gain,.... Na da,...
 

H20Rat

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Really dont wanna spend the cash for captains call but I am going to run internal silencers . I want a little sound but not obnoxiously loud , plus obviously want the performance gain .

At best, you will gain ZERO hp. Most likely you will actually lose power. Can't get much better than a vacuum behind the prop sucking the exhaust out of the engine.
 

sean.deangelis

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Do this before you cut the transom or buy any exhaust mod pieces. I did it to my (Volvo Penta) 5.0 and am very happy and still have happy lake neighbors:
Purchase one of these for $20.00
http://www.amazon.com/Sierra-18-4456-Exhaust-Protector-Valve/dp/B0001CLCTA
Then remove your exhaust bellow(s) and replace with that flap on the transom exhaust outlet.
My experience has been what I consider a great sound from the SB Chevy while on plane. At idle the whole thing is submerged so you can puts through the marina in silence. It also allows me to run pretty much any swim platform on the market with no interference issues. I have put 60 hours on my boat with this setup and not had a single issue. Here is a pic of what I'm talking about...keeping in mind that I have a Volvo Penta not a Merc:
 

jryotas

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no , I get that it will not be a noticeable performance gain . I though have a huge issue when it comes to personalizing cars and trucks and boats . Have owned many of each and none were ever left stock . How boring would this world be if we all were made the same and not allowed any change or personalization . So ye s, i get that if I run straight pipes , it will sound like some rednecks truck , or worse , but I am going to run baffles and have heard other small blocks with similar setups and they sounded appealing .

My main concern was whether or not the exhaust tubing , even if it were 12" long between the riser and the tip , would be able to stand up to the heat produced . I have decided that I am prob going to run a splicer pipe in between anyway just to be safe . Thanks again for all the replies
 

Scott Danforth

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if you are hell bent on running thru-hull exhaust. the company you are buying them from have tips and tubing for the installation. they even have the hand-dandy instalation instructions that tell you to measure twice, cut once, then order the stuff between your elbow and transom
 

NHGuy

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If you use marine rated stuff it will work fine. Remember there is water in the exhaust to cool it.
 

achris

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Really dont wanna spend the cash for captains call but I am going to run internal silencers . I want a little sound but not obnoxiously loud , plus obviously want the performance gain . The only lake we are on is full of Bajas and big go fast boats so everyone there is use to the noise . Its either loud exhaust or loud stereos .
Thank You everyone for the replies

There will be ZERO performance gain. Period.

The fact is due to a loss of the exhaust in the low pressure area behind the propeller you may actually go SLOWER!
 
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HT32BSX115

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Yeah. I had Capts Call when I had the 460 In my Liberator........When I switched it from thru-prop to thru-hull it was LOUD!

Everybody in the boat would say TURN IT OFF TURN IT OFF!!!!!!!!!!!

I couldn't tell any difference in performance at all......

When I pulled the OMC 460 and installed the Merc 454, I left the Capts Call on the floor........it does seem to work better there anyway........:rolleyes:
 

midcarolina

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Well............. To answer your question, Instead of straying off and giving you opinion on a side subject that you did NOT ask advice on

I would use a piece of SS pipe and keep the hose down to as short as possible...........remember to double clamp at all connections.
 

500dollar744ti

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no , I get that it will not be a noticeable performance gain . I though have a huge issue when it comes to personalizing cars and trucks and boats . Have owned many of each and none were ever left stock . How boring would this world be if we all were made the same and not allowed any change or personalization . So ye s, i get that if I run straight pipes , it will sound like some rednecks truck , or worse , but I am going to run baffles and have heard other small blocks with similar setups and they sounded appealing .

I understand where you are coming from. I have the same feelings about personalizing my stuff. I actually have all the stuff to do a through-hull exhaust in my garage. Right as I was marking and measuring to cut the holes for exhaust, I decided against it. I said I would wait until I can get a switchable system. For the prices these 'captains call' systems are going for, I've been able to put together a 6.2L stroker motor for my boat.

I'm going with the stroker motor instead of through-hull now. I just go too many places that have no-wake zones, narrow waterways and quiet marinas, especially at night.
 

Walt T

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When I was young and stupid I loved loud exhaust on my cars and boats. Now I'm old and stupid and loud exhaust for no reason other than to be loud irritates me. I do love the sound of racing engines be it drag or circle track, I just hate it on the street or water. Had a C4 that had side pipes which I got rid of and installed a nice sweet dual exhaust with some very quiet turbo mufflers. The car was definitely quicker off the line with the slight increase in back pressure. A lot of circle track motors have venturis installed in the exhaust to squeeze the exhaust just a little and produce a bit of back pressure which is a major help in cylinder scavenging. Wide open pipes are useless and stupid and will get the attention of local water cops. Chicks don't dig it, they'd rather hear a great stereo.
 

jryotas

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May 20, 2013
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Wanted to thank every one of you for you opinions and input . I get everything installed today and am very pleased . I installed 4" Hardin tips with internal flappers and am also going to run external flappers just to be safe . The tips also have removable baffles to quiet it down a lil . On the inside , I was able to find a local muffler shop that had chrome over stainless 4" exhaust tips that we cut to 10" and they made perfect splice pipes between the tips and the risers . Looks better than 16" of black exhaust hose would have looked anyway . The sound is just what I was looking for and I can wait to get it out on the water .

On another note , I also just ordered our new tower from DIYwake and will be installing it soon as well as a set of Bazooka 8" tower speakers . Now I will get the chicks that like the loud exhaust and the ones who like the loud stereos ;)
 
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