Converting from Thru Hull to Corsa Call

[briggs09hp]

Hello,

Im looking at purchasing a new boat. Its a performance boat with twin Mercruiser 454's. It is currently set up with thru hull exhaust. I love the sound of thru hull, but i know many people do not. So if I get this boat, I would like to install silent choice or corsa call exhaust.

So the boat currently does not have any Y pipes in it. The exhaust runs from the manifolds, right out through the transom. So in order to convert this boat to have both thru hull, and thru prop exhaust, I will need to buy and install the y pipes for both engines, and the diverters/solenoids for both engines.

I read that you need to remove the engines to install the Y pipes. Is this true? By Y pipe i mean the part of the exhaust that leads from the risers, down to the out drive and comes together at the drive and goes out to the exhaust bellows. There are no exhaust bellows installed either. Are all of these parts available? I am working with Corsa Marine now to get a quote. But I just wanted to know if anyone has converted a boat with thru hull to have thru prop as well. It seems like Corsa sells the diverters and parts needed to convert a thru prop boat to have thru hull. But not really a thru hull boat to have thru prop.

Thanks,

Matt

 

[HT32BSX115]

Re: Converting from Thru Hull to Corsa Call

I read that you need to remove the engines to install the Y pipes. Is this true?

Hi Matt,

I have a boat that had a Corsa Capts Call installed. When I removed the 460 to replace with the 454, I didn't reinstall the Capts call.

It was just too noisy.

I am thinking about maybe installing it in the future though since there's some pretty nice marine mufflers that you can put in the transom fittings that will quiet it down considerably.

Yes. You MUST remove the engine(s) to install the y-pipe...........no other way to do it.

Cheers,


Rick

 

[emilsr]

Re: Converting from Thru Hull to Corsa Call

The parts are available (unless you have extension boxes in which case you'll have todo some fabrication) but its going to be an expensive proposition. Also, depending on which 454's you have they may not be happy with thru prop exhaust (454 mag for example).

In some locations, switchable exhaust isn't legal so you'll need to check that.

There are a few good mufflers available; both switchable and non-switchable. If you're just looking to quiet the boat at idle, another solution is turndowns.

 

[Bondo]

Re: Converting from Thru Hull to Corsa Call

Hello,

Im looking at purchasing a new boat. Its a performance boat with twin Mercruiser 454's. It is currently set up with thru hull exhaust. I love the sound of thru hull, but i know many people do not. So if I get this boat, I would like to install silent choice or corsa call exhaust.

So the boat currently does not have any Y pipes in it. The exhaust runs from the manifolds, right out through the transom. So in order to convert this boat to have both thru hull, and thru prop exhaust, I will need to buy and install the y pipes for both engines, and the diverters/solenoids for both engines.

I read that you need to remove the engines to install the Y pipes. Is this true? By Y pipe i mean the part of the exhaust that leads from the risers, down to the out drive and comes together at the drive and goes out to the exhaust bellows. There are no exhaust bellows installed either. Are all of these parts available? I am working with Corsa Marine now to get a quote. But I just wanted to know if anyone has converted a boat with thru hull to have thru prop as well. It seems like Corsa sells the diverters and parts needed to convert a thru prop boat to have thru hull. But not really a thru hull boat to have thru prop.

Thanks,

Matt

Ayuh,.... The motor's gotta come out to install the y-pipe...

'n,... Yes, the parts are available from Merc, aftermarket, or used....

 

[90stingray]

Re: Converting from Thru Hull to Corsa Call

A set of mufflers might be the answer. A heck of a lot easier option.... just something to consider.

 

[briggs09hp]

Re: Converting from Thru Hull to Corsa Call

Yeah I was also looking at the mufflers. They seem to be alot easier to install. Ill call Corsa and see what they have and what they cost. The 454's are rate at 420 HP stock. But i was told the previous owner added a roller cam.

I called the state police that patrol our lakes (finger lakes, NY) and asked them if there are any sound regulations. They told me there is a sound ordinance in effect. But they do not have the tools to measure the boat sound out on the lake. So what they do is measure the boat at idle, 1 meter from the exhaust outlets, and you have to be under 90 db. So I guess as long as im under that, i should be ok. Im worried, because although i have not heard this boat i want to buy run yet, I did hear another Fountain run. And I was screaming at my dad standing next to me, and he couldn't hear what I was saying. With one engine running. Granted it was on a trailer, parked outside a building, and there was no water in the engine cause they we winterizing it. But it was loud.

Other than Corsa, are there any other mufflers available? Corsa seems to have exhaust muffler tips. Are there any in line mufflers that I could install in the boat? Just trying to do some research.

Thanks,

Matt

 

[Bondo]

Re: Converting from Thru Hull to Corsa Call

Yeah I was also looking at the mufflers. They seem to be alot easier to install. Ill call Corsa and see what they have and what they cost. The 454's are rate at 420 HP stock. But i was told the previous owner added a roller cam.

I called the state police that patrol our lakes (finger lakes, NY) and asked them if there are any sound regulations. They told me there is a sound ordinance in effect. But they do not have the tools to measure the boat sound out on the lake. So what they do is measure the boat at idle, 1 meter from the exhaust outlets, and you have to be under 90 db. So I guess as long as im under that, i should be ok. Im worried, because although i have not heard this boat i want to buy run yet, I did hear another Fountain run. And I was screaming at my dad standing next to me, and he couldn't hear what I was saying. With one engine running. Granted it was on a trailer, parked outside a building, and there was no water in the engine cause they we winterizing it. But it was loud.

Other than Corsa, are there any other mufflers available? Corsa seems to have exhaust muffler tips. Are there any in line mufflers that I could install in the boat? Just trying to do some research.

Thanks,

Matt

Ayuh,.... So yer in NYS,.... Captains Call is illegal,... No operator switchable exhaust is allowed in NYS...

NYSP, 'n the DEC both do the checkin' 'round here/ 1000 Islands areas...

From experience, I can tell ya, yer gonna have Problems, til ya get the exhaust tips, Below water level, at idle, at the dock....

Mufflers or not...

'n, check out some Hot Rod Boat sites,...
There's Ton's of shops spittin' out various mufflers or many designs, 'n a few, actually work...

 

[briggs09hp]

Re: Converting from Thru Hull to Corsa Call

What kind of problems did you have?

How can i get the tips below water level? Wouldn't water get into the engine?

 

[emilsr]

Re: Converting from Thru Hull to Corsa Call

Turndowns (Gibson makes 'em) will get the exhaust below the water line. So long as the exhaust flappers are working you won't get water back up in the exhaust. Tall risers help there, but unless the previous owner did something your 420's should be set up this way.

The downside to these is they're ugly, but they do work. It'll still be loud once you're on plane though; to fix that you'll need muffled tips. Teague sells a few different flavors. I'll find out which ones a friend put on his 750's and report back. They took him from 100+db at idle to 88db and he only lost about 150rpm.

 

[briggs09hp]

Re: Converting from Thru Hull to Corsa Call

I do not think there are any risers or elbows on these engines. Here is a pic (hopefully they work). It looks like the chrome or SS exhaust plumbing bolts right to the manifolds and then out the transom.

Thanks,

Matt

 

[Tail_Gunner]

Re: Converting from Thru Hull to Corsa Call

You may want to post a thread at offshoreonly...I am quite sure many have experience with this over there.

 

[Bondo]

Re: Converting from Thru Hull to Corsa Call

I do not think there are any risers or elbows on these engines. Here is a pic (hopefully they work). It looks like the chrome or SS exhaust plumbing bolts right to the manifolds and then out the transom.

Thanks,

MattView attachment 174604View attachment 174605

Ayuh,... Can't tell where the risers end, 'n the tailpipes begin,...

They might be full length dry exhaust risers,... Donno...
Can't tell where the water mixes...
If they're Dry to within inches of the tips, That's a Loud boat...

To meet the Test, you could remove those flappers, 'n bolt on 90? elbows,...
They could run down a foot, then open,...
It'd be dead quite at the dock, but still rumble as soon as the water level drops at the transom, on plane...

Yer swim platform oughta hide the ugliness...

 

[briggs09hp]

Re: Converting from Thru Hull to Corsa Call



Here is another picture. It looks like a hose from the thermostat housing runs into the chrome exhaust plumbing. So that has to be a wet exhaust doesnt it? I sure hope so. Otherwise, yeah its gonna be loud. When I looked at it, I think I remember there being rubber hoses and clamps at the transom. So its gotta be wet exhaust.

How does dry exhaust work? How does the Raw cooling water exit the boat?

 

[Bondo]

Re: Converting from Thru Hull to Corsa Call

View attachment 174630

Here is another picture. It looks like a hose from the thermostat housing runs into the chrome exhaust plumbing. So that has to be a wet exhaust doesnt it? I sure hope so. Otherwise, yeah its gonna be loud. When I looked at it, I think I remember there being rubber hoses and clamps at the transom. So its gotta be wet exhaust.

How does dry exhaust work? How does the Raw cooling water exit the boat?

Ayuh,... What yer callin' chrome plumbin' is SSteel risers,...

A pipe within a pipe,... Water still goes out through 'em,...

Question is How Far,..??

Lift up the flappers, 'n look in to see the mixin' ports...

Is there a joint anyway in the chrome plumbin', 'tween the manifold, 'n transom,..??

 

[briggs09hp]

Re: Converting from Thru Hull to Corsa Call

The boat is 3 hours from me. Next time i go look at it ill shine a flashlight up the exhaust and see.

Yes I think I remember there being a joint inside the boat before the transom.

 

[HT32BSX115]

Re: Converting from Thru Hull to Corsa Call

The boat is 3 hours from me. Next time i go look at it ill shine a flashlight up the exhaust and see.

Yes I think I remember there being a joint inside the boat before the transom.

You'll want something like the following for mufflers. They make the boat "legal" for most states noise req.

http://images.inetgiant.com/large/5578385/img_1911721419G_2T.jpg

And something similar to the following.


http://www.boatstoreonline.com/images/corsa5.jpg

To make it "work", as some of us indicated above, you'll need either used or new Y-pipes, and whatever plumbing to match it all up.

I have a complete Corsa Captains Call divertor setup that I removed from my previously installed OMC 460.

To make it work with my 454 Bravo, I'll need to get some 4" stainless steel tubing and cut to match it all up and weld it all together so that it matches my currently installed thru-hull locations and Y-pipe......not a really BIG "deal" to make it happen..........

If you have a suitable saw and GTAW ("TIG") welder you can easily do the fabrication necessary to hook it all up. If not, you'll need to pay someone else to do it OR buy all the "plumbing" pre-cut/welded to do it. It won't be "cheep" for twins. Those mufflers are something like $600-800 a pair..... And I think the divertor valve system is something like $800 per engine.....