Underwater Silent exhaust

rbcool · Post by **rbcool** » Thu Oct 07, 2010 4:25 pm

Anyone here have the underwater silent exhaust option? If so, what do you think?

Tri-Guy · Post by **Tri-Guy** » Thu Oct 07, 2010 8:23 pm

I have the underwater exhaust on my tri cabin.The exhaust is very quiet but I cant sync up the engines by ear,I need the syncronizer.I took the thru hulls out to rebed them,they are very stout solid bronze.The only thing I dont like about them is the 3.5 inch holes in the bottom of my boat. Good luck with your new purchase,any questions feel free to ask I have done almost everything to mine.

rossjo · Post by **rossjo** » Thu Oct 07, 2010 9:24 pm

Tri-Guy wrote:... 3.5 inch holes in the bottom of my boat ...

Holy bottom, Batman!

Thats scary!

rickalan35 · Post by **rickalan35** » Thu Oct 07, 2010 9:54 pm

Somehow this reminds me of that 1955, 34 foot Shepherd cruiser I once owned in my youth - with twin 331 Chrysler Hemis for power. It too (like my tricabin) was a V-Drive with those wonderful Walters. Can anyone say.... "POWER!!!!!" ..... like in spades.

When I bought it, it had four, thick, black rubber hoses attached to the exhausts. Those hoses extended down beneath the surface of the water in an attempt to reduce engine noise and possibly to also reduce exhaust penetration into the cockpit at low RPM's.

A mechanic came by one day and informed me that with the exhaust hoses attached in that manner I would be prone to sucking in the entire lake should my engine backfire or if it began dieseling after I had cut the ignition. Needless to say, the hoses came off.

Was he pulling my leg?????

Wouldn't be the first time I have been led down a garden path. At my first job they sent me in search of a left handed monkey wrench.

Rick

summer storm · Post by **summer storm** » Thu Oct 07, 2010 10:08 pm

rickalan35 wrote:
A mechanic came by one day and informed me that with the exhaust hoses attached in that manner I would be prone to sucking in the entire lake should my engine backfire or if it began dieseling after I had cut the ignition. Needless to say, the hoses came off.

I think if that was the case then every sterndrive boat out there would have problems

BTW first job= going down to the engine room to ask the chief engineer for compass bearing grease

Tri-Guy · Post by **Tri-Guy** » Thu Oct 07, 2010 10:14 pm

All tri cabins with the engines under the salon with straight drives are like this.I like the system,but at the same time I am aware that an exhaust hose failure would be very very bad.It seems the way it is designed water ingestion is not a problem.The system is very quiet and the thru hulls are very strong.

rossjo · Post by **rossjo** » Thu Oct 07, 2010 10:26 pm

Rick - good excuse to run straight exhaust if you ask me

you should hear my old Vette!

rickalan35 · Post by **rickalan35** » Thu Oct 07, 2010 10:31 pm

I want that Vette

rbcool · Post by **rbcool** » Thu Oct 07, 2010 10:38 pm

Thanks guys. I'm sure I'll have a lot of questions. I do love the quiet though, nothing like the twin 454s in my Searay.

rossjo · Post by **rossjo** » Thu Oct 07, 2010 10:53 pm

Searay? ... be quiet ... don't tell anyone you own a Searay ... sailboat is OK, but a Searay?

rbcool · Post by **rbcool** » Fri Oct 08, 2010 5:39 am

LOL..... don't have her anymore. I've moved UP in the world!

aaronbocknek · Post by **aaronbocknek** » Fri Oct 08, 2010 6:14 am

every late model tri cabin i've looked at has this system. while i understand the concept, it scares the crap out of me knowing that a hose failure could be catastrophic. i HATE the idea of all that underwater gear just waiting for something to happen. are there any known incidences of these particular exhausts failing on a trojan? rob, what did your surveyor say when he looked at them? are they just holes in the bottom or capsule like pods?

rbcool · Post by **rbcool** » Fri Oct 08, 2010 6:32 am

On mine the muffler looks exactly like an air bag on a tractor trailer and it's flexable, which is the only thing I dont like about them - they vibrate a good bit at 1,200 rpm but then are very smooth. But I also am a little weary about the hole in the bottom so I'm installing special engine water intake valves that can be reversed to take water out of the bilge in an emergency. I realize the "What If" question about a problem at the slip but thats why I heavy insured her.

aaronbocknek · Post by **aaronbocknek** » Fri Oct 08, 2010 6:43 am

good idea rob. i wonder if anyone has retrofitted these exhausts to vent out above the waterline. i know there is an 'idle' function that routes the water and smoke out the side and once you start moving, the exhaust is pulled in the other direction to vent underneath the boat. i will never forget the first time i saw this when i started my search..... it really creaped me out just thinking about the 'what ifs.'

Tri-Guy · Post by **Tri-Guy** » Fri Oct 08, 2010 12:44 pm

Arron its not that big a deal with proper maintanace.When I first got the boat 4 years ago I was worried a little,now its just one more check before heading out.The system on my boat does not have mufflers just exhaust hose,dont let this stop you from buying a later model tri cabin.The benafits of having the engines under the salon without v-drives is worth it.