Boats with Thru-Hull Exhaust

[18WCmerc]

Re: Boats with Thru-Hull Exhaust

Except his distributor is in the wrong place, but other than that it's sexy.

lol i like Chevy better, its where my roots are, even though i rock a ford

 

[23eagle]

Re: Boats with Thru-Hull Exhaust

I agree with the prudes in here and also hate thru- hull exhaust but for entirely different reasons. Through hull exhaust is waaay too quiet for my taste.

The only way to go is 8 unmuffled 2 1/2 inch pipes. The neighbor kids love it too

Adding through hull exhaust only requires a hole saw and a few small exhaust changes.

Did you make sure those boys were not drinkin, before you handed over the keys to the boat ?

 

[briggs09hp]

Re: Boats with Thru-Hull Exhaust

Haha, I didn't expect this to turn into such a big discussion, but that's good. Seems like there are alot of people who like it and people who hate it, but I guess that's how it is with pretty much everything.

So why cant I satisfy both crowds? Can someone explain exactly how thru-hull works? Are there mufflers or is it just pretty much like a straight pipe right out the back of the boat? If its a straight pipe, then yeah i can see how people hate it, but a muffled V8 is quiet enough and still sounds pretty good. What is this Captains call? Is it a system where i can choose to direct the exhaust either through hull or through prop? Whats wrong with that? That sounds to me like the best way to go.

The exhaust manifolds on some pictures of engines I have seen look way more complicated than an automotive exhaust system. How come I see water coming out of the pipes of some exhausts when the engine is running? Are the manifolds more complicated because there is engine coolant (water) pumped through them? Is this some sort of exhaust cooling system?

Sorry for all the questions. I really am new to boat engines.

Thanks again,

Matt

 

[Chris1956]

Re: Boats with Thru-Hull Exhaust

Matt, Most I/Os have elbows on the exhaust manifolds(actually the exhaust risers) that direct the exhaust down into the outdrive, and out the prop. The water acts as a muffler, and the boat runs pretty quiet. Thru-hull exhausts have an extension to the exhaust risers that pipe the exhaust straight back and thru the transom. since the exhaust exits above or only partially below the water, there is no muffling or minor muffling.

Captain's choice is a selectable exhaust, with a Y pipe connecting the risers to either the outdrive or the straight pipes. The position of a valve to direct the exhaust is controlled by the captain.

There is no HP or torque advantage to either method of exhaust.

 

[QC]

Re: Boats with Thru-Hull Exhaust

In both cases there is water (or coolant in some examples) surrounding the manifolds, risers and from there out actually in the exhaust. This is primarily to keep the heat in the engine compartment down. In your car there is air circulating in large qty's from underneath, and if there is a fire, you pull over and get out. Difficult in a marine application . . . .

There are dry headers used in some applications (as shown with the headers picture), but they open air engine compartments and the headers do not go "through" any fiberglass or other hull material.

In general Chris is correct about power, particularly with small blocks. When you get into Big Blocks, and particularly ratings above 500 bhp, then through prop exhaust is a choke point and never used.

 

[HollaGeo]

Re: Boats with Thru-Hull Exhaust

Some boats leak oil. Some break down in the middle of a channel. Some don't observe the "No Wake Zone". If you have a thru-hull exhaust it's fine. I would say if you were planning on docking your boat at some Yacht Club in the Hamptons, then maybe you would have problems. At a "down to earth" marina on a lake. You'll be fine. Who cares what people think when on the water and moving...

 

[Chris1956]

Re: Boats with Thru-Hull Exhaust

Hey Holla, I disagree. There are two performance boats that run open exhausts that "live" on my lagoon in NJ. When they idle down the lagoon to the bay, the noise is deafining, and the vibration is severe. Once they are out in the bay is is much less on an issue, due ot the open space. Luckily they only come by a couple of time on a weekend, because all activity ceases until they are well out in the bay.

I would be embarrassed to run those things. You can imagine what I think of their intellect and manhood.

I could not imagine how bad it would be on a small mountain lake, surrounded by peaks, to reflect the sound.

 

[Sharp Shooter]

Re: Boats with Thru-Hull Exhaust

Hey Holla, I disagree. There are two performance boats that run open exhausts that "live" on my lagoon in NJ. When they idle down the lagoon to the bay, the noise is deafining, and the vibration is severe. Once they are out in the bay is is much less on an issue, due ot the open space. Luckily they only come by a couple of time on a weekend, because all activity ceases until they are well out in the bay.

I would be embarrassed to run those things. You can imagine what I think of their intellect and manhood.

I could not imagine how bad it would be on a small mountain lake, surrounded by peaks, to reflect the sound.

Are you really that sensitive? Is mega sensitivity a trait that defines manhood? I take it you've never attended a concert before and run like a little girl when caught in a thunder storm.

 

[Sharp Shooter]

Re: Boats with Thru-Hull Exhaust

In both cases there is water (or coolant in some examples) surrounding the manifolds, risers and from there out actually in the exhaust. This is primarily to keep the heat in the engine compartment down. In your car there is air circulating in large qty's from underneath, and if there is a fire, you pull over and get out. Difficult in a marine application . . . .

There are dry headers used in some applications (as shown with the headers picture), but they open air engine compartments and the headers do not go "through" any fiberglass or other hull material.

In general Chris is correct about power, particularly with small blocks. When you get into Big Blocks, and particularly ratings above 500 bhp, then through prop exhaust is a choke point and never used.

Prop exhaust will always be more restrictive than a decent thru hull system regardless of Cubic inches (big block or small) and neither will flow as well as a good tube header design.

 

[tswiczko]

Re: Boats with Thru-Hull Exhaust

I have thru hull on my boat and haven't heard anyone complain

 

[Lyle29464]

Re: Boats with Thru-Hull Exhaust

Prop exhaust will always be more restrictive than a decent thru hull system regardless of Cubic inches (big block or small) and neither will flow as well as a good tube header design.

This is 100% true.

However it is not unusual for a small block to have a small increase in power with bit of back pressure at top RPM.

 

[642mx]

Re: Boats with Thru-Hull Exhaust

I would be embarrassed to run those things. You can imagine what I think of their intellect and manhood.

Why are you wondering about other people manhood for?...lol.

My open exhaust has nothing to do with the size or use of my manhood. Its about the sound, the experience, the performance boat thing. Try not to be jealous of what others can afford, life is simply too short.

 

[642mx]

Re: Boats with Thru-Hull Exhaust

Prop exhaust will always be more restrictive than a decent thru hull system regardless of Cubic inches (big block or small) and neither will flow as well as a good tube header design.

I agree, and so does my wife. She's a skiier and can tell a difference with the exhaust running out the prop or when its opened up... especially when she's getting up on one ski. I always leave the exhaust open when I pull her up and then I shut it off once on plane when she is skiing, she loves the sound of open headers, but not at 75 feet away at 2700 rpm....lol

 

[642mx]

Re: Boats with Thru-Hull Exhaust

So why cant I satisfy both crowds? Can someone explain exactly how thru-hull works? Are there mufflers or is it just pretty much like a straight pipe right out the back of the boat? If its a straight pipe, then yeah i can see how people hate it, but a muffled V8 is quiet enough and still sounds pretty good. What is this Captains call? Is it a system where i can choose to direct the exhaust either through hull or through prop? Whats wrong with that? That sounds to me like the best way to go.

They do make a muffler tip for boats. A friend just bought a Baja H2X and its got them. They sound good at idle, but once you get into the rpms they are way too quiet and sound more like a 6 cylinder.

Captains call has a diverter valve in the exhaust that can channel the exhaust thru the prop or straight out the back. Most people remove the valve as its just one more thing that can go wrong. I kind of like mine for watersports, but could also live with open exhaust 100% of the time.

Corsa makes a Quick and Quiet system also... with the Q & Q, some of the exhaust gets routed out the back with thru hulls and then some of the exhaust gets routed thru the prop. There is no switch or choice on this system. They are quieter than straight thru hulls, but the boat still has some rumble and the nice chrome tips running out the back.

The exhaust manifolds on some pictures of engines I have seen look way more complicated than an automotive exhaust system. How come I see water coming out of the pipes of some exhausts when the engine is running? Are the manifolds more complicated because there is engine coolant (water) pumped through them? Is this some sort of exhaust cooling system?

The water is flowing to help cool the headers and to help with the noise. Dry pipes are a lot louder than wet pipes.

 

[Sharp Shooter]

Re: Boats with Thru-Hull Exhaust

This is 100% true.

However it is not unusual for a small block to have a small increase in power with bit of back pressure at top RPM.

That depends on the engine combo and it's not specific to size.

Unless you're dyno tuning multiple sets of headers you'll never realize if or how much back pressure may or may not help an engine. Some headers are designed with removeable collectors to "fine tune" the back pressure.

 

[642mx]

Re: Boats with Thru-Hull Exhaust

Here is some more ear candy for the non-haters... http://www.youtube.com/watch?v=ZrnDRSj4kaU

 

[HollaGeo]

Re: Boats with Thru-Hull Exhaust

Edit

 

[haulnazz15]

Re: Boats with Thru-Hull Exhaust

I agree, and so does my wife. She's a skiier and can tell a difference with the exhaust running out the prop or when its opened up... especially when she's getting up on one ski. I always leave the exhaust open when I pull her up and then I shut it off once on plane when she is skiing, she loves the sound of open headers, but not at 75 feet away at 2700 rpm....lol

Make her ski 15-20' off and see if she likes it closer the boat.