Fabbing up a through hull exhaust???

[76slickcraft]

I'd just like to start off by saying hello. This is my first time at this forum.

I have a 1976 Slickcraft SS 194 with a 302 I/O. It has a wet exhaust and raw water cooling. I would absolutely love to have a though hull exhaust. Right now the exhaust goes into a big Y pipe after the risers and exits through the prop hub. Well I was thinking of getting two 3" stainless steel exhaust pipes (one for each side) and running them out the sides where I would cut a hole in the side of the boat and have them exit there. Side pipes! When I run the boat in the driveway hooked up to the hose, the water moving through the system muffles the exhaust quit a bit.

My question is first of all, will this screw up the cooling at all? The water should still exit out the exhaust.

Also, is there any problem with cutting holes in the boat?

I love V8 noise....hopefully I can make this work. Here is a picture of my boat the day I pulled her out of the junk yard! I ran her hard the entire summer without a single problem. Didn't use a drop of oil.

Anyway, I'm looking forward to being a part of this forum. Seems like there is a lot of great information on here.

Steve

 

[drewpster]

Re: Fabbing up a through hull exhaust???

Depends on where you live but on most lakes in the U.S. there are laws against open exhaust. I would advise against it. Mechanically I am sure there is a way to do it but, and I mean this with all respect, its just stupid. And I think I speak for everyone who enjoys a little peace on the water.

No offense. Welcome to the forum.

 

[Scaaty]

Re: Fabbing up a through hull exhaust???

Stick with what ya have. Designed for it...(and yep on the noise)

 

[JasonJ]

Re: Fabbing up a through hull exhaust???

I highly recommend, if at all possible, that you spend a day in a boat with open exhaust. V8 noise is fun, but when it is just a loud droning like in a boat, it gets tiring listening to it.

Another factor that cannot be eliminated is the SAF (Spousal Acceptance factor). If you are married, the wife will put up with it for three minutes. If you are not married, the girlfriend will put up with it for ten minutes. If you are single, it is a rare woman that likes loud boats so you may find yourself just riding with dudes. Nothing fun about that.

Like is has already been said, check you local laws on noise, more and more lakes are going to open exhaust bans. That noise carries all the way across lakes, and gets old for the people who live and play on those lakes. I am not saying to not do it, it's your boat. I'm just sayin' that since there will be no real power gain, your quest for noise will not have enough payoff to be worth it.

In anotherwords, the ladies love quiet boats ...

 

[tashasdaddy]

Re: Fabbing up a through hull exhaust???

the costs and agraviation is going to far out way the benefits, and also make it extremely hard to sell in the future. everything is going to have to be custom. $$$$$

 

[mkast]

Re: Fabbing up a through hull exhaust???

He's experimenting.
Why stop at cutting holes in the hull?
Cut holes in the house, to better hear the exhaust!

 

[76slickcraft]

Re: Fabbing up a through hull exhaust???

Damn, you guys are tough.

A few things...

I paid damn near nothing for the boat and trailer that had a newly rebuilt engine (less than 10 hrs).

I'm handy, I could do it for the cost of some exhaust pipe.

I love to modify things and make them my own (you should see my cars)

If it was overly loud, I'd come up with a muffler system.

I live in VA Beach.....the Elizabeth River is damn near like the ocean. I don't think I'd get pulled over for making noise when there are offshore racing boats racing past the nuc subs and aircraft carriers.

And finally, how many Slickcrafts do you see with a through hull exhaust...not many.

I do value everything said. Espeically Jason. Well put and I definitely have to think about what it would be like when we go skiing or tubing.

I was asking what kind of problems as far as cooling and such that I might run into. Just trying to get all the informatilon I can so I can make a decission on wether this would be something I'd like to try.

Steve

 

[tashasdaddy]

Re: Fabbing up a through hull exhaust???

want noise, try this:

http://cgi.ebay.com/ebaymotors/18-C...tegoryZ80653QQihZ015QQitemZ250085043104QQrdZ1

 

[Laddies]

Re: Fabbing up a through hull exhaust???

You will get tried of the noise but I had a freind do it he went out the back because of the fumes of side exhaust, you will need to change the elbows to straight out instead of 90 degree down and remove the y-pipe and cap the bottom hole (he cut his y-pipe and plugged it because he said that he wasn't going back) and install the hull fittings wearever you want them

 

[mkast]

Re: Fabbing up a through hull exhaust???

I realize that you had a legitimate thought and wanted to know how to pursue it. What most people on these boards will tell you is, "If it ain't broke, don't fix it!"I know you're real handy with swinging wrenches, there's more to it than that.
In reality, if you don't use an exhaust system like Captain's call (stainless steel), or you don't know what you're doing (read Coast Guard Regulations) don't go screwing around with your boat.
Old farts will tell you, after the modification, "Don't you wish it was original again? They're usually right.
Is your boat insured? Do some mods to your boat, then find out the policy is void, after the fact. They are trying to save you money, time and embarrassment.

 

[kalla man]

Re: Fabbing up a through hull exhaust???

from the pics and the purchase price, i somehow dont think slick has the boat insured, and i do not believe "Old farts will tell you, after the modification, "Don't you wish it was original again? They're usually right." no modification ive done to a boat was ever regretted, I could see how one like this very well could be regrettable, but if a loud exhaust makes you happy, and does not disturb nature and other boaters (being in open water like you mentioned), then do what makes you happy and make your boat loud. personally I do not enjoy boats(mine or others) that are louder than necessary, and anyone whos ever fished on a lake with air-boats on it will agree im sure. So , Go For It........ As long as i dont have to listen to it ~~~~~~~~~~~~~~~~~
THE PROJECT.......
s99.photobucket.com/albums/l309/kallaman/

 

[iwombat]

Re: Fabbing up a through hull exhaust???

You might want to consider adding a rev limiter to the mix if you don't have something like that already. One slip of a shifter, and you could easily blow a motor with no exhaust back-pressure and no load on the engine. You'll also want to consider the size of the exit pipe. Truly wide open exhaust is nice and loud, but it tends to eat valves and valve guides if not given enough back pressure.

I've built lots of hot-rods and street dragsters and I get your attraction to loud. However, loud and open can eat a motor right quick if you're not careful.

Rev limiter and good back-pressure are things you'll want to keep in mind.

 

[Chris1956]

Re: Fabbing up a through hull exhaust???

Slick, You will want to go thru the transom. You do not want waves hitting the pipe ends, which happens more on side pipes. You want some drop down from the elbows to keep the water out of the motor. You want to some some rubber tubing to allow the motor to move on it's mounts. The water cooling of the pipes must be sufficient to keep the rubber from melting. You need to secure the pipes to the hull in a waterproof fashion, or the transom will rot.

There are kits for this, which are widely available.

 

[JasonJ]

Re: Fabbing up a through hull exhaust???

Mkast brings up a good point. A system like Captains Call allows you to have your loud exhaust fun, but can be switched to thru-prop when its time for some peace & quiet, but you are looking for a way to do your project without spending a ton of loot.

iwombat is right about back pressure. You may end up with a loud boat that actually performs worse than before, you need the backpressure for torque production, and you don't want to ruin your engine. Good luck...

 

[ManOfwar690]

Re: Fabbing up a through hull exhaust???

there is a two way exaust valve you can use that if you want it to go out thrue the stearn or thre the lower unit at a flip of a switch my friend used it and its slick

 

[Saskatoon2005]

Re: Fabbing up a through hull exhaust???

Final note,

check with local goverment regulations? Can you have open exhaust in your boat in your state? Some States don't care, some do....that will tell you if you should or not. Personally I wouldn't touch a thing....Great job on finding such a catch...LOL!

 

[Terrulle]

Re: Fabbing up a through hull exhaust???

personally I do not enjoy boats(mine or others) that are louder than necessary, and anyone whos ever fished on a lake with air-boats on it will agree im sure. So , Go For It........ As long as i dont have to listen to it ~~~~~~~~~~~~~~~

This may be off topic but I have to dispell the myth about airboats. The engine is not what makes all of the noise.... It's the prop. Regulations say that any inboard should have a noise suppresion device. A Game Warden quoted this to me. I believe that this regulation refers to when big blocks in ski boats were popular in the 60s-70s. The mufflers don't make much difference on airboats....and there insn't much you can do about the prop noise. In defending airboats.... they don't kill manatees or hurt grass beds as outboards do. Sorry for the noise. Slickcraft..... to conform with regs just install glasspacks...

 

[flabum]

Re: Fabbing up a through hull exhaust???

Mercury and Gil along with a few other manufacturers sell an exhaust valve (Silent Choice, Captains Choice etc... ) that will allow you to switch between thru-hull and thru-drive exhaust. You will, however, need to change out your exhaust system to a center rise setup. Not hard to do, but costly.