thru hull exhaust

[wca_tim]

So are you saying that if I do run it throug say a pair of 4" diameter emi mufflers and a couple of elbows between the risers and tips it would probably be fairly quiet? That's actually what I'm hoping to accomplish... (sorry to hijack the thread)

 

[CheckmateFever]

Really i don't think the 350 is all that offensively loud with standard thru-hull exhuast. Yes the water coming thru does make a difference and you do get a nice throaty V-8 sound. Don't quote me on this but i think the small blocks with wet thru-hull exhaust are still within the Db laws from what i've read and heard from other boaters. I know i've passed many lake patrol cops and they've yet to bother me for my exhuast. But i'm kinda biased...i like everything i own to be obnoxiously loud . Cars, trucks, boats, guitars....

 

[wca_tim]

I've heard quite a few with straight through hull exhaust (wet and dry set-ups) and although I love the sound of all of em, i'm looking for quieter than even a typical wet system run straight back... This is the boat built to take my daughter (13) and her friends skiing and boarding, do some occassional fishing, run the river, sound, intercoast with and that we're plannig to hit a number of lakes and so forth with this summer. nothing wrong with being a little low key... "walk softly and carry a big stick"....

Besides, after we get this one right, dad (me) gets to start shopping for a starting point for something that's a LOT more of everything...

 

[TLB]

Really i don't think the 350 is all that offensively loud with standard thru-hull exhuast. Yes the water coming thru does make a difference and you do get a nice throaty V-8 sound.

I agree, my 350 with wet thru hull's is not all that loud.
Last summer I was going up the Saginaw river in it's long no wake zone with the marine patrol boat just behind me on a Sunday afternoon and I thought to myself we are about to see if it is too loud. Just past the end of the no wake zone we let it rip, so did the marine patrol boat when I got to the next no wake zone they just idled on by giving us a , so I guess it's not too loud,,, in my area.

 

[Big Dave]

Mine drops below the steering before turning out the back, so there is no way to put mufflers on it. and with the steep drop before the turn out, no problems with revision even with the very lopey cam in it.... I love the sound, but it is difficult to hear skiers.

LOUD PIPES SAVE LIVES

 

[wca_tim]

Hey dave, remembered how yours was, and thought hard about it... for what I want this time, am going to try coming out higher and to the outside of the steering assembly. I'll take pics once i get around ptu making the time to put it together.

 

[Big Red]

So are you saying that if I do run it throug say a pair of 4" diameter emi mufflers and a couple of elbows between the risers and tips it would probably be fairly quiet? That's actually what I'm hoping to accomplish... (sorry to hijack the thread)

I would not bother with the mufflers its only a small block 350. I would try it without the mufflers first. If its 2 loud for you, then buy the mufflers. The mufflers are pretty expensive. Its very rare around here to see mufflers on anything unless its dry exhaust.

Even my jetboat isn't as loud as it looks with water injection. But if you are that worried about sound leave it alone. Why bother with thru hull exhaust on a 350 if you are going to quiet it down so much it will sound like a new 4cyl running. If you want the look just bolt 2 exhaust tips on the back.

 

[remlinger]

I would not bother with the mufflers its only a small block 350. I would try it without the mufflers first. If its 2 loud for you, then buy the mufflers. The mufflers are pretty expensive. Its very rare around here to see mufflers on anything unless its dry exhaust.

Even my jetboat isn't as loud as it looks with water injection. But if you are that worried about sound leave it alone. Why bother with thru hull exhaust on a 350 if you are going to quiet it down so much it will sound like a new 4cyl running. If you want the look just bolt 2 exhaust tips on the back.

Still love the look of those over transom exhaust.

 

[wca_tim]

I would not bother with the mufflers its only a small block 350. I would try it without the mufflers first. If its 2 loud for you, then buy the mufflers. The mufflers are pretty expensive. Its very rare around here to see mufflers on anything unless its dry exhaust.

Even my jetboat isn't as loud as it looks with water injection. But if you are that worried about sound leave it alone. Why bother with thru hull exhaust on a 350 if you are going to quiet it down so much it will sound like a new 4cyl running. If you want the look just bolt 2 exhaust tips on the back.

LOVE the jetboat! has got to be a blast to run!

Your point is well taken, but even if the risers weren't going to be too long to run the Y-pipe, it's too restrictive. I'm replacing a v-6 with a 383 and will be running IMCO Power Flow manifolds and risers. Hopefully even with mufflers it won't sound like a 4 cylinder...

Independent of how it winds up running, it's starting to look good... Thanks everyone for the thoughts...

 

[CheckmateFever]

LOVE the jetboat! has got to be a blast to run!

Your point is well taken, but even if the risers weren't going to be too long to run the Y-pipe, it's too restrictive. I'm replacing a v-6 with a 383 and will be running IMCO Power Flow manifolds and risers. Hopefully even with mufflers it won't sound like a 4 cylinder...

Independent of how it winds up running, it's starting to look good... Thanks everyone for the thoughts...

Wow, nice lookin engine! 383 stroker is what my future plans may have instore for my Enchanter but that's still a few years off. Is that a crate motor or did you build it yourself?

 

[wca_tim]

I wish I could say I built it and was going to, but when I went looking for a quality machine shop, I discovered that there's a guy in th enext town that builds offshore racing and circle track engines for a living. everyone I asked, said I should go talk to him. Long story short, easily the best machine shop I;ve ever dealt with and since they specialize in marine builds they had run about ever possible combo of off the shelf parts and played with it all. He know off the top of his head which combination of parts and machine work would work the best and had the majority of the starting parts on hand... I went ahead and had them assemble the bottom end and heads and then I've put the little pieces togethre and painted things as it came together. Seeing how they did things as it came along, I don't think there is any way i could have done the ojb they did. Made me feel like a hack just to watch....

We put all forged botom end parts in and it was carefully balanced, bueprinted starting with the block, tolerances between cylinders were so close I couldn't tell a diference on the micrometer or dial indicator. Hopefully it'll run great and hold together for a while. I was told that if I keep good oil in it that it will last as least as long as a new merc engine with the way they put it together - even pushing a lot more horsepower...

Sorry to ramble... Just got finished buffing a few light scratches out of the risers that came in the mail today...

 

[daren34]

on the starlet i had the swim platform was in the way to exit above the steering

daren

 

[wca_tim]

So where did you come out? Just curious....

 

[SneakyPete]

I had GLMs and a full wet thru hull with S bends on my Enchanter. It sounded good, wasn't loud, but turned heads. I was able to carry on a conversation with everyone in the boat no problem. I have since upgraded to a Stainless Marine system with super long risers and s bends, it is almost fully dry, it is deafening. You can't here anything but the exhaust when you are behind the boat. Carry on a decent conversation in the cockpit? Forget about it....I love it. Yours will sound nice and not be intrusive if you use factory style/length risers...it will be like a fine wine, a nice combo of flavors but none overpowering (btw I drink Guiness...)

 

[LieFREEorDIE]

how can you tell if it is dry or wet exhaust
i am going to look at a starfire 350 with thru hull exhaust
is there a way to know other than water exiting out the pipes?
sorry im a little new to powerboats but somewhat mechanically inclined
if you could help me tell the difference like the bends in the pipes or
whatnot it would be appreciated

 

[81 enchanter]

you can look and see if it has water hoses from the cooling system running to the manifolds. if its the big monster stock manifolds they are for sure wet exhaust. about 95% of the time its a wet exhaust.....if not they better have some kind of muffler on there cause that baby would be loud!!

 

[Big Dave]

Mine is full wet w/ stock manifolds and s-bends to go below steering and is still really loud( I love it)

Dry exh would use water to cool manifolds, but would have a water hose going to transom to release water instead of mixing it with the exhaust after the risers