Thru hull exhaust conversion
 

My boat doesn't even begin to compete with the boats on this forum but it is what I can afford at this point in my life. I am running an 89 Wellcraft Eclipse 216 with a small block 305 that sat in a climate controlled storage facility for 13 of its 22 years. The interior is all new and the gel looks like new as well. So at least it isn't falling apart!
I am hoping to convert to a thru hull exhaust system next season and was wondering if anyone has any idea what the cost of materials would be for the conversion. A "captains call" or "silent choice" option would be welcomed I am sure by my wife as she does not seem to share in the enthuthiasm that I do of the glorious sound of a performance boat.

The cheapest route would be to just buy a set of tips, exhaust hose, and something to cap off your Y pipe.

Any of the silent choice options will really increase your budget unless you can find some used parts.

How is the local law enforcement in your area about noise?

You're probably going to need 3-4' of marine exhaust hose which will run roughly $100-150, 8-16 hose clamps at $5 a piece, exhaust tips for $150-200, $110 or so for Y pipe caps if you decide to not do a switchable exhaust plus another $20 or so for gaskets and hardware. I'd throw in some more fudge money to cover for tools, sealer etc to get the job done.

Depending on where the exhaust can exit it may involve some additional pipes for turn downs etc.

Check your PMs.

If your motors are atleast somewhat stock, I would definitley utilize the Y pipe in your thru-hull project. I think it will have a better sound, especially with small blocks. It will be a little quieter, but will also sound deeper at idle. I just went back to a Y pipe after years of tinkering with tips and mufflers and I finally got the sound I wanted. You can buy just the diverter pipes w/o the valve and its pretty cheap (see Dennis Moore, I think he's on this forum) then you just control your sound (db's) through restriction in your tips...alot of the Corsa tips are made with some restriction in them, forcing some of the noise back through the Y pipe. Good Luck!

Great advice guys. So it seems that i should be able to get this project accomoplished for under a grand in parts. Gonna have a marine mechanic buddy of mine do the work for me.

Hey liquidlounge.... what type of boat did you convert and was the end result worth the time and money?

Heres a pic of my little dingy....

http://www.slednh.com/forums/index.p...__1#entry71580

http://www.mooreperformance.info/Tri...austPipes.html

Here's a link to what I was talking about. You could always upgrade to a silent choice type system later if you wanted and you would just be out the $175.00. Yes, I would say it was worth it. I had to pull my motor to re-install the Y pipe which took some time, but the boat has never sounded better even with the silent choice open, which is what yours would be. Regardless of what you decide, I would leave the Y pipe.

Post a pic of the transom. If it has a "cut out" in the middle where the drive is, it might complicate the project.

Pretty clean looking 1989

Hmmm... interesting. Does this system allow you to route the exhaust through the hub when my wife has had enough of the noise or is it stricly thru hull?

It routes the exhaust through both at the same time with no provision to route it strictly through the prop. You would have to install slip in silencers in the exhaust tips or in line mufflers if you wanted to quiet it down any which is the premiss of using that particular setup.

Slip in silencers run about $80 on the low side. Mufflers are several hundred. I knew that was your next question.:p

Ahhhh... u know me well grass hopper....its almost like we have spoken on another plane or u have a crystal ball?:drink:

If you are prop exhaust only now and you want to go thru-hull.Make sure the risers are high enough vs were you want to cut the holes.You could wind up with a reversion problem.Its a really nice boat my advice is have fun with it and run it.

Don't expect this modification to deliver much in the way of "increased performance". It's only going to make more noise and go the same speed.

I've had a lot of boats, some of them were really loud, some of them were whisper quiet. After the novelty of a loud, slow boat wore off, I decided that I liked quiet boats unless the extra noise was required for extra performance.

I had an outboard that I had to wear earplugs in else my ears would ring that night when I tried to sleep. Open velocity stacks, big carbs, midsection exhaust reliefs, and 8500 rpm. I'm talkin loud.

At the performance level you're at, I would REALLY advise you to do this cheaply and in a manner you can reverse it if you choose to. If you upgrade to a 383 stroker smallblock with a blower, then you'll definitely need to run thru hull exhausts to realize the full performance of that combination, but for now it really isn't necessary.

But if you think running glasspacks on a V6 Camaro is a cool idea, then don't let me stand in your way.

MC

That is one clean Classic........


matt

if you have end riser "log" type mercruiser manifolds you will need to switch to center riser type manifolds and risers.

for a small block chevy the kit with two manifolds, two risers and all the hardware will run you about 500 on ebay. add in tips, clamps, wet hose and assorted hardware and you will be at just under a grand.

i did the exact same thing to my 18' 1975 searay but i have a real hot small block ford in it. i had to change everything from the heads out and i had 900 bones or so in it. i bought the 4" stainless tips with flappers and internal mufflers and the manifolds and risers from dennis more. it's only noisy from behind! not much difference in the cockpit when cruising but ski behind it and it sounds like a dragstrip.

do it, do it now! lol.

hope this helps. have a good night, rob.

This is true.

x2

Depending on how your transom is setup you can limit how much exhaust noise you hear in the cockpit/cabin by strategically placing the exhaust tips lower in the water.

If the transom is anything like the one on my 232 eclipse, your gonna be doing a LOT of plmbing to get it below the platform, or go above like I did.

Just remove the bellows and put the money you are going to spend in to replacing that 305 with a 350. its like night and day even if its just a stock motor you put in.

Thaks for all the input guys. I am seriously looking into a Rex Marine Sound Selector exhaust cutout system. The system is used and is available for a fair price I believe so I am not dumping a ton of cash into a boat, motor, trailer package that I only paid 4G's for. I will post a few pics of my engine bay and transom to get peoples opinions on what to do.

As for my purpose to do the conversion. It is for "the noise" not speed. Boat does a wholloping 52mph at WOT on gps with a 3 blade 14pitch "tug boat" prop as my mechanic calls it. I will be moving towards a 4 blade 17 pitch next season. i am hoping to see a blistering 55mph??? hahaha But if that doesn't happen that is fine too... again my purpose is to obtain that beautiful music exiting the transom.

WOW
with at best a 1.5 ratio and zero prop slip that would be spinning the engine just over 6,000 rpm with a 14 pitch prop

Okay maybe I am mistaken I will have to look at the prop size again.lol

Stock small block does not make enough noise to be annoying. Throw some inline mufflers in them and they'll be quiet but 'loud enough' to hear some rumble.

Make sure you are quieter than the noise laws on your lake. Which you will be with inline muffs or in tip muffs. No reason to cause trouble with a low hp set-up.

==========================

55 with a stock 305 ?
If true, Build a mild 350hp 5.7 and you will be mid 60's to upper 60's.

See you on the trails............I ride Twin Mt a lot as I live on Lake Winni.

How well does that 305 plane out? I had one back in the 80s and got sick of asking people to walk up to the front when we took off. Tossed it in the dumpster with less than 40hrs on it. Its a cheap swap. You might like the sound if you just take the bellow off. Try it, It wont cost you anything.