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David Ross
"Navigator"




Joined: January 02 2007
Posts: 452
Posted: February 01 2014 at 02:16 | IP Logged Quote David Ross

Bob, I did mean to use the first and second "which" and I know "why". It was a attempt to add to the dry wit. Guess I failed in, history, english and comedy. Hopefully things here will work out and we can back into Connie info exchange instead of this stuff.



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DAVE
GOOD SPIRITS
500 CONSTELLATION (1987)
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David Ross
"Navigator"




Joined: January 02 2007
Posts: 452
Posted: February 01 2014 at 02:27 | IP Logged Quote David Ross

Bob,the comma after the word "in" was not a punctuation error, it was a typo. Don't need another failure. Hope I didn't mess up on any spelling. It certainly will be nice to get back to boating topics...



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DAVE
GOOD SPIRITS
500 CONSTELLATION (1987)
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NautiKall
"Seaman"




Joined: January 22 2014
Posts: 73
Posted: February 01 2014 at 11:31 | IP Logged Quote NautiKall

Obviously my attempt at comedy failed.  I recall some previous posts where grammer was being challenged. Sorry.  Back to boat stuff.

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1985 Connie 460
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Pete37
"Commander"




Joined: November 12 2006
Posts: 2317
Posted: February 01 2014 at 12:07 | IP Logged Quote Pete37

Hi John,

Subject: Your post of 1/31/2014 20:09

Thank you for your hate letter of January 31. Unfortunately your posts and letters tend to resemble the name of your Connie.

There may not be a conspiracy of ďbuddiesĒ but there certainly is a cabal of four owners who are working together against the welfare of the Forum. And your statement that virtually every poster has complained independently is ridiculous. It has been mainly those four in the cabal but they have bitched repeatedly and at every opportunity so it may seem like a lot more.

Regrettably, bitching, personal attacks and hate letters accomplish nothing useful. Be specific. I could say (with some justification) that you have been obnoxious for years but I donít.

You seem to be preoccupied with the concept that somehow you and your cabal members have the sole right to post on the forum and that posts by other members will interfere with your posting rights. If you see a post that doesnít conform to your concept of what the world should be like just ignore it. You arenít required to respond to every post. Let others post and respond as they see fit.

Way back in 2006 Boat US created the Manufacturerís forums. They created a forum (on paper) for just about every boat manufactured at the time. There were hundreds of these paper forums but the flaw with all of them was that they had no members. Eventually, the Manufacturerís Forums developed but out of hundreds of forums only two were really successful.

They were the Chris Craft Cavalier and Chris Craft Constellation forums. Why did these two forums succeed while hundreds of others never took off or folded? The answer is that they had forum mentors who cared about and nurtured their forums. And I was the creator and mentor of the Chris Craft Constellation forum. Boat US created the structure of the forum but I provided the members by sending out about 200 letters; one to every Connie owner in the US.

It is amazing that the Connie forum with a maximum possible number of members of less than 200 could outperform nearly all of the other forums. Only one, the Chris Craft Cavalier forum, slightly leads the Connie Forum. But the Cavalier Forum has a maximum possible number of members of over 1000. Recently that lead has been dropping.

So perhaps my mentoring hasnít been too bad.

I donít own this forum, you donít own this forum, the members of the cabal donít own this forum and even the members of the forum collectively donít own it. Boat US owns the hardware and software of the forum but even they donít own the members. A forum, by definition, is ďan assembly for the discussion of public mattersĒ. No one can own that.

Pete37


Edited by Pete37 on February 01 2014 at 12:36


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diveryates
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Joined: January 02 2007
Posts: 845
Posted: February 01 2014 at 13:42 | IP Logged Quote diveryates

We humans are complex creatures- maybe to extraterrestals we're not particularly, but in our egotistical selves we are and that, of course is a two edged sword.

The subject at hand concerning sound attenuation I feel is worthy of further serous investigation earning a concerted effort to extentuate the positive.

In our imperfect human condition, all we can hope for in our presumably advanced intelegence, is to utilize as best we can, our abilities of self-desipline and the awareness of the knowing-ones-self aspect to counteract our collective, compromised state.

I'm really interested in looking into the possibilities of turning down engine noise. I'm already half deaf from being a professional rock-n-roll bass player who gigged for 35 years (mostly without earplugs- dumb!), gunfire, aircraft engines, jackhammers, screaming kids and God forbid, loud boats...
There are a lot of powerful minds here and I see that as a very good thing.

From studying photos we took of Lorelei's muffler system, one thing that is not clear in Centec's drawings is that the intake and output ports on the muffler are BOTH WELL OFFSET FROM CENTER. This is key for the geometry is again, is not clearly detailed by Centec.


Diver

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'83 280, hardtop, single 305
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DMark
"Deckhand"




Joined: July 03 2007
Posts: 131
Posted: February 01 2014 at 13:55 | IP Logged Quote DMark

I'm in a similar situation Roy. I have Munieres and have lost
significant range in my hearing along with picking up
significant "head noise", which is not measurable. I'd really
like to see how this muffler discussion plays out. I'm one of
those people who'd pay a premium for even a small amount
of improvement.

Pete, about your 5GB data base. Any chance you're willing to
make another copy?

Mark

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NautiKall
"Seaman"




Joined: January 22 2014
Posts: 73
Posted: February 01 2014 at 17:20 | IP Logged Quote NautiKall

Diver Mark and other muffler fans.

  I'm excited.  The big mufflers should fit with a little rework on the 460. The situation should be similar on the 500.
 The existing mufflers rest on their 8" nozzels on plywood supports.  The body of the new 16" dia muffler will extend 8" further aft than the existing.  I plan to cut off horizontally the aft plywood support, remove the rubber cuffs that seal the joints where the muffler nozzels meet the hard fiberglass pipe and remove the old muffler.  Some of the aft exhaust piping may need to be removed to get the old muffler out.
  The problem is in getting the new 16"dia muffler in and under the cabinet.  The opening you can see in the port side photo is not big enough.  The toe board will have to be removed for more clearence.  Not a big deal. The new muffler has a 50" long 16" dia body with an 8" nozzle on each end.  The incoming nozzel is centered and the outlet nozzel is offset up 3 1/2".
  After cutting the outlet hard pipe back for a 66" gap between incoming and outlet pipes where the new muffler will go, we will cut back the insulation about 10" on the 8" pipes stubbs where they will meet the muffler nozzels and thoroughly clean the pipe surfaces.  A little vaginal jelly will be smeared on the cleaned pipe ends and new 10" long rubber cuffs slid onto the pipes.  After positioning the new muffler between the 8" exhaust pipe ends, the rubber cuffs will be slid 5" onto the muffler nozzels and double banded on muffler nozzel and exhaust pipe.
  The forward end of the muffler will be supported by the nozzel in the original plywood support.  The aft end of the muffler will be supported under it's 16" dia body after the correct height is determined by sistering a plywood saddle on the plywood nozzle support at the aft edge of the hanging locker that had been cut down for muffler removal.  Next, replace the toeboard, the mahogany panel

and viola! The port side is done.
  The muffler is mostly under the hanging locker on the port side.  What you are looking at is the 8" discharge pipe after the muffler.
  The starboard side procedure will be essentially the same, but, is slightly different in that the muffler is about 8" further aft.  Probably due to location of the A/C in the mid-cabin. The new longer muffler may cause an interference with the back of the safe which snugs up against the 8" exhaust pipe aft of the muffler.  It will be close.  If there is interference, I'll have to install a new mahogany panel and move the safe a few inches aft.
  Starboard side photo.


Edited by NautiKall on February 01 2014 at 21:48


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"NautiKall"
1985 Connie 460
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DMark
"Deckhand"




Joined: July 03 2007
Posts: 131
Posted: February 01 2014 at 17:35 | IP Logged Quote DMark

When do you plan to have the work done again?

The acid test will be in the hearing/perceived sound levels. I
know Pete cautioned about engine noise as a contributor, so,
it'll be very interesting to read your take on the holistic
outcome. I'm crossing my fingers.

One of my close friends owns a 57 Carver, which is pretty
quiet. I know I'll never get there, but closer would be a good
thing.

M

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Pete37
"Commander"




Joined: November 12 2006
Posts: 2317
Posted: February 01 2014 at 17:53 | IP Logged Quote Pete37

Hi All,

Subject: Mufflers

Well, it's nice they fit. So for about $3,500 you can have a new pair of mufflers. But the mufflers are only going to be about 20 dB mufflers. Not much more than than the 18 dB mufflers you already have.

I have hearing problems too and wear a hearing aid part of the time. Lost some of my hearing in the Army. It's not that I can't hear but that I can't distinguish certain sounds. 105 mm howitzers will do that to you.

With the new muffler in place your sound level at the FB helm will be about 67 dB at 1000 rpm. and about 80 db at 1800 rpm versus 69 dB at 1000 rpm and 82 dB at 1800 rpm. with the old muffler. Either way you could stand more than 16 hours of exposure without hearing damage as shown in the following figure:







The mufflers protect you on the FB but they won't protect you in the engine room, at the lower station, in the upper salon, lower salon or on the aft deck.

For that I've carried a pair of ear muffs for years. I keep them hanging in the engine room but you can hang them anywhere you want. You can pick up a decent 20 dB pair for under $20. For $40 you can get a super comfortable pair. 30 dB muffs are also available at a slight increase in price.

Some of you will say "Aw, ear muffs are inconvenient." but of course that's why you lost some of your hearing in the first place.

Conclusions
My conclusion is at low speeds (up to 1500 rpm) the existing mufflers are completely adequate. For high speeds (1800 rpm) wear ear muffs if you think you need them. Take the $3500 you saved and buy a nice satelite TV.

Pete37

PS: I told my wife that I was considering new mufflers for the boat at a cost of $3500. I didn't need my hearing aid to hear the answer to that. It was a resounding NO!!! in 28 flavors. At least I won't have to argue with her about that. Now I have an easy in for the satellite TV. So thanks Bob, you may have done me a favor.




Edited by Pete37 on February 01 2014 at 20:02


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diveryates
"Lieutenant"




Joined: January 02 2007
Posts: 845
Posted: February 01 2014 at 18:54 | IP Logged Quote diveryates

Mark and Pete have a point. These replacement mufflers really need to be quiet...and advertised as such. Would spreading a wider net bring in other Mfgr's? Do 'modern'
boat builders like Carver, Legacy, Silverton, guys who make planeing cabin cruisers have different muffler sources? Centec mentions larger size= quieter- not very encouraging for limited space set ups or little allowance to change geometry, particularly where there's little up/down allowance like Cat 280 muffler installations. On Cats, The muffler has about a 2" clearance of the hull bottom.
Centec can't be all there is, and if they are (which I'm skeptical of), they owe their customers better choices in the 21st century of modern manufacturing. I am making a presumption that what gives the juicy sound Cats and Connies make just might be straight thru with little or no actual baffling and where water contributes some attenuation, but not much... on purpose> what Calif. greasers call 'glass packs'. Perhaps the non-centered inlets and outlets aspect of the Centek muffler in Lorelei might be all there is?
Has anyone seen a busted up muffler up close or a cross section where one can get an idea of the inside of these things? This is one area where Centek or for that matter any muffler mfg'r will be hesitant- this sort of stuff is their stock-in-trade and they won't give it up, especially if it really works.
Diver

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'83 280, hardtop, single 305
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eshover
"Deckhand"




Joined: July 02 2011
Posts: 205
Posted: February 01 2014 at 20:01 | IP Logged Quote eshover

Diver - " I am making a presumption that what gives the
juicy sound Cats and Connies make just might be straight
thru with little or no actual baffling and where water
contributes some attenuation, but not much..."
I could not agree more. As I have stated in previous
posts; I have had the opportunity to pull my exhaust
system down to where I could flush the exhaust line from
the engine room bulkhead out through the transom. I
could see daylight entering from the transom as a I ran a
heavy duty (as stiff as I could find) through the exhaust
tube as far as I could.
I cannot swear to it, but it felt as though there was a
"movable" baffle within the muffler that I could move
somewhat. That could have been my imagination.

Emory

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"Southern Charm"
1986 Connie 500
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eshover
"Deckhand"




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Posted: February 01 2014 at 20:02 | IP Logged Quote eshover

I would like to add that it is also my opinion that the baffle
serves to block water from travelling back up the exhaust.

Emory

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NautiKall
"Seaman"




Joined: January 22 2014
Posts: 73
Posted: February 01 2014 at 22:59 | IP Logged Quote NautiKall

Thanks for the downer Pete.
  I'm getting a little tired of the negative B S.  When I grow up I'll be more capable of making my own good decisions. Until then I'll look for good advice. Since your boat is quiet you need to back out of the discussion.  Your head is not in it. I'm well aware of how ear protection works.  I spent 32 years in an industry where noise levels for people were an issue.  However, I'm not about to buy twelve or fourteen sets of ear muffs for my guests to wear on the boat.  I want to quiet my boat.  Then again, it might be a good cost saving to buy ear muffs than to up-grade the mufflers.  You can do a cost analysis on that.  By the way, my guests don't go in the engine room when we are under way.
  I know that todays two stage mufflers are better than cheaper straight through types. Yes I have looked at other manufacturers. Cheaper mufflers are available.  Yes. we have 2 cycle engines. Yes, Centek is the Cadillac in the industry.  Yes, I have made some assumptions on application.
  I'm an experienced engineer, remember? We get our professional license' based on our experience and our ability to make decisions based on assumptions from actual practice. Many text-book geniuses' are rejected due to no experience. I understand your lowering my anticipated outcome because you know that the frequency of my exhaust sound waves on my boat are below the level for maximum performance.  How do you know that?  Was that in a book?  Or did you get that from your radio shack meter behind a Detroit 671 TI at all of the different rpm's on the curve?  I'll be the first to say "I don't know" if I don't know.  There is no reason, ever, to fake it to win an argument.

 Back off or I will stop sharing the details, unless you have a positive contribution or some humor.  I don't need this. I'm sharing information because others might benefit.  You can take it or leave it.  If you can't stop attacking the discussion, back off as you promised to be an occasional contributor.  Your repeated position on up-grading mufflers is no different today than it was many days ago.  This isn't a contest about who can win his point.  Try listening. I'm sorry the Centek guys  won't talk to you. I'm willing to put my money where my mouth is.  Hopefully many of us will benefit from my step forward.  If it doesn't work, I'll report that back.
Enough, and I don't need the "hate mail" response.

To others I apologize, I'm new here but I am already tired of the constant conflict by one person.

Bob K.
 

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Pete37
"Commander"




Joined: November 12 2006
Posts: 2317
Posted: February 02 2014 at 11:50 | IP Logged Quote Pete37

Hi Bob,

Subject: Mufflers

You seem to have an odd concept of what ďnegative B.SĒ. is. It appears that anything you donít agree with is ďnegative B.S.Ē The graph shown in my last post was from a US government report (the EPA I believe). Iíll get the exact particulars if you want them.

You claim to be an engineer but you are not acting like one. An engineer would respond to my graph with solid evidence that something was wrong with the graph. Instead you respond with invective and insults. And when I present solid evidence you ignore it. Probably because you know you canít contest it.

The graph shows that the permissible exposure time at 85 dB is 8 hours. The text accompanying the graph states that permissible exposure time increases by a factor of 2 for every 3dB decrease in noise level. With the old muffler in my boat the noise level at 1800 rpm is 82 dB (best estimate) or 3dB less than 85 dB. So the permissible exposure time is 16 hours.

I operate most of the time at 1400 rpm and at that speed the sound levels are way below 85 dB. Permissible exposure times would be measured in days or perhaps even weeks. So the only time any kind of hearing risk would exist would be when I was running at top speed.

I have no reason to believe that my Connie is any quieter or noisier than any other Connie. The only solid measure of noise levels we have is that taken by me with a Sound Level Meter. You have not produced even one scintilla of solid evidence on the noise levels from any Connie.

How do I know the sound frequencies of a diesel exhaust? It came from another government report the results of which were in my post of the 29th. Iíll get the exact particulars if you want them.

For occasional cruises with your guests they would need no hearing protection unless the time at maximum rpm exceeded 16 hours or unless they were standing closer to the exhaust than the FB station such as the aft deck. And if you have fourteen guests on your flybridge you are getting very close to the point where capsize is possible.

If you are sharing information based on facts that is very commendable but most of what I have seen is based upon unsupported supposition. Grow up, act like an engineer and present facts.

The ďhate mailĒ response was not directed at you.

Pete37


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NautiKall
"Seaman"




Joined: January 22 2014
Posts: 73
Posted: February 02 2014 at 12:26 | IP Logged Quote NautiKall

Pete,

Are you serious?  or Is this your brand of humor?  Again, I know all of your points.  I can read.  Consider yourself relieved of managing my affairs.

Today is Boy Scout Sunday.  Do a good turn daily.  Send a check to your local Council.

Bob K.


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1985 Connie 460
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diveryates
"Lieutenant"




Joined: January 02 2007
Posts: 845
Posted: February 02 2014 at 12:30 | IP Logged Quote diveryates

Nautikall,
I gleaned a couple of points from your post:

1)' Two stage' : does this mean two individual components like a lifter muffler and a horizontal thru muffler or a single assembly utilizing a multiple function single assembly: integral sound baffles, anti backflow capability and/or a portion where water is still designed to do attenuation? Maybe a single unit that does a bit of all this?

2) It sounds like you have had some success locating improved design muffler systems be they multi or single component installations(?) If so, very cool. Can you share what you have found please?

3)If I picture this right, sound energy's gotta go somewhere, presumably absorbed into muffler internal baffles, transmitted to the muffler body and hence thru the mounts to the hull at a reduced energy level. Or a lot of the energy is out the back like a trumpet attenuated by exhaust water. Depending on the absorption attributes of water, increasing or decreasing raw water flow may affect energy absorption. This gets a bit complicated as the issue also affects engine cooling. I' thinking conduction is the deciding factor but is a bit over my head. A already-available Mo-betta mouse trap would be... better.
Does the geometry of Connies eliminate the need for lifter mufflers? Without liters, sound energy will not get reduced as much as with lifer units built in.

Trying to get as much info out of you before and if you bail- hope you don't! You seen to have a firm grasp of the issues involved. fascinating stuff.

Diver

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DMark
"Deckhand"




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Posts: 131
Posted: February 02 2014 at 13:25 | IP Logged Quote DMark

Okay I'm confused and would appreciate some help.

On one post I see that we're not exactly sure what model
number the circa 1985, 86, 87 mufflers are. So we don't
know exactly the sound attenuation specs.

Then I see us assume about 17-18 dB, which relates to a
muffler we assume matches the original. Okay got that.

Then I see an attenuation curve for the new muffler that
peaks at 30dB at 250-ish HZ but sits at 20-ish at 125 Hz.

Okay - so that would lead us to assume that the low HZ
attenuation of the new muffler is only marginally 2 dB better
than the old one. Got that.

But doesn't the frequency of the motor noise go up as the
RPMs increase? (It does on my boat...) So would it make
sense that this new muffler is designed to increase attenuation
as the RPMs increase? Net does the new muffler "try" to
maintain a relatively flat "net" attenuation?

Or, am I way over thinking this???

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"NANCY CAROLYN" ('86, CC500)
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NautiKall
"Seaman"




Joined: January 22 2014
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Posted: February 02 2014 at 14:00 | IP Logged Quote NautiKall

Diver,

Good questions.  My opinion is only from my research over the past year or so after I decided I was tired of putting up with loud noise on my otherwise very nice boat.  I don't pretend to be the last word on the subject.  I've received a lot of input from others with recent experience not from out-dated text books and publications.

A good muffler system in our boat applications does the job with one component.  A two component system is usually found on a modern automobiles, where there is a muffler and then a resonator.  Modern autos are essentially silent.  Boat applications usually don't have enough room for one good muffler, much less two.

Two types of mufflers:

 Straight thru type, which is less costly and smaller in size, has a thru pipe, of exhaust pipe diameter, perforated with holes surrounded by a larger container packed with sound absorbing materials. All indications are that we now have straight thru type mufflers.  Better sound attenuation was attempted by making the units larger.

Dual Stage type,  has a pathway for the exhaust gas, of exhaust pipe diameter, that reverses itself several times in a larger container.  There are baffles, some with holes, creating separate chambers that the high velocity gases have to flow thru. When the sound waves are reversed in direction against incoming gas flow there is canceling of sound waves.

Dual Stage mufflers in our 8" size create a very minor 1 to1 1/2 psi back pressure.  There is no sound absorbing packing which can be saturated with oil and water, in a Vernatone Dual Stage muffler.

Water flow thru a muffler has little effect on sound deadening.  The water flow is to cool the heat of combustion being discharged from the engine.

Lift mufflers are for smaller engine applications and are primarily for situations where the engine and muffler is below the water line.  Often used for motor/gen units and small engines in run-a-bouts, fishing boats or sailboats where the muffler sits on hull or boat bottom.  Fortunately our exhaust systems are above water and will drain freely.

Hopefully no exhaust gas noise is transferred to the boat hull.  The muffler installation will be cushioned at the supports to prevent vibration being transmitted to the hull.  Engine noise (vibration) can be transmitted to the hull if the motor mounts are deficient (separate issue - The violin effect talked about in an earlier post).

The manufacturer of our mufflers, Vernay Industries in Yellow Springs, Ohio was bought out by Centek Industries several years ago.  Centek now manufactures mufflers for large yachts and cruise ships; 200 HP up to 2000+ HP.  They know what they are doing.

I hope you understand my brief explanation.  I know it will be debated.

Bob K.



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"NautiKall"
1985 Connie 460
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NautiKall
"Seaman"




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Posted: February 02 2014 at 14:09 | IP Logged Quote NautiKall

Good thinking Mark.  Also, the attenuation effect is not a straight line resultant affair.  The result is a quadratic equation, which means as db improvement occurs, the sound attenuation increases to a greater degree.

Bob K.


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1985 Connie 460
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DMark
"Deckhand"




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Posted: February 02 2014 at 14:16 | IP Logged Quote DMark

Thanks Bob,

So if that's true - this new Centek muffler might be very
worthwhile. I think I'm more interested and more hopeful.

Mark

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Pete37
"Commander"




Joined: November 12 2006
Posts: 2317
Posted: February 02 2014 at 14:28 | IP Logged Quote Pete37

Hi Dmark,

Subject: Diesel Sound Distribution Curves

No Mark the sound distribution doesn't change much with engine loading. The sound curves move up with loading but remain peaked at about 125 Hz. The distribution also remains about the same but the whole curve moves up by about 10 dB. Diesel noise doesn't get schriller with increasing rpms.

This is all shown in the second curve of my 1/29/2014 7:58 post.

I wish some people would read and try to understand that post. Bob K. refuses to acknowledge that it even exists.

Pete37

PS: Boy this web site is getting slow!

Edited by Pete37 on February 02 2014 at 14:37


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DMark
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Posts: 131
Posted: February 02 2014 at 15:42 | IP Logged Quote DMark

Okay, so big picture summarization and questions...

The original mufflers really don't deteriorate naturally
themselves much over-time. But they do go bad
occasionally...

Centek designs and builds a new muffler at about $3,200/pair
as a slightly better replacement for the original because, while
there might be a small replacement business there's really no
economic reason to spend the engineering money to
substantially increase attenuation performance. Maybe its
just a muffler repurposed or reapplied to the 6V92 because it
works "close enough" as a replacement requiring no additional
engineering investment...

I can't help wondering why Centek would build a muffler that
peaks attenuation at 250hz when the motor peaks sound
pressure at 125hz... Is this Centek muffler really designed for
the 6V92 or is it really designed for another motor with a
different sound pressure curve? Any clues?

If its really designed for a different motor that would lead us
back to a search for a different muffler solution.

Thoughts?

Mark

Edited by DMark on February 02 2014 at 15:48


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Pete37
"Commander"




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Posts: 2317
Posted: February 02 2014 at 18:13 | IP Logged Quote Pete37

Hi Mark,

Subject: Mufflers

Yes, the original mufflers (if theyíre Centek mufflers) donít seem to degrade with age. At least thatís what Centek told Bob in one of their discussions. But we still donít really know what the original mufflers are. We found a Centek muffler that sort of looks like the original but we canít positively identify it without itís serial number and model ID. In any case though, our mufflers arenít Centek mufflers because Centek bought out the original company only a few years ago. I donít recall the name of original company at the moment.

Donít know what the economic benefit of increased attenuation is. If you asked Bob he would probably say enormous. But most mufflers are bought by yacht manufacturers for installation as original equipment on their yachts. Who the hell asks about the mufflers when buying a yacht? I think the muffler replacement market is tiny. There must be some interest in mufflers though because sound levels at the helm are listed in many boat descriptions.

I was sitting in the doctorís office a few days ago reading yacht magazines while waiting for my wife to finish her appointment. They were my magazines, not his. I try to avoid doctors with megayacht magazines in their waiting rooms. But for some reason six of my monthly boating magazines were all dumped in my mailbox on the same day.

In one magazine, a modest Hatteras 100 was described which had lower helm noise readings running from 64 dB at 600 rpm to 82 dB at 2350 rpm; about the same as a Connie. This was one of those multi-million dollar ďPrice-Upon-RequestĒ yachts. And most of the yachts reviewed in the magazine had higher noise levels than that.

Makes me wonder why we in our little yachts are so uptight about the sound levels. If the millionaires can stand it why canít we?

I doubt Centek cares much about 6V92s. They are obsolescent engines that arenít found on many new yachts and Centek sells mainly to yacht builders. If you look at the Centek sound diagrams you will find that almost all of them have similar shapes. Itís probably just the physics of it that give you peaks at 250 Hz for mufflers designed for 125 Hz.

Pete37


Edited by Pete37 on February 02 2014 at 18:40


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DMark
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Posts: 131
Posted: February 02 2014 at 18:24 | IP Logged Quote DMark

I know I'd like a quieter ride and would be more than happy
to pay for mufflers that are materially quieter. I do envy my
neighbor with the Carver... If Bob runs his experiment we'll
see how that goes.

We'll see if anyone else has a thought on the topic, but sounds
like the mufflers are a little better but not a superior
technical/spec match for our boats if a quieter ride is the key
interest.

Bob, I may not have captured that very well from your POV.
Its not a critique, just an attempt to boil it down as this
discussion has been difficult for me to track. I am clearly not
an engineer. Just a fanatic boat lover...

M


Edited by DMark on February 02 2014 at 18:34


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Pete37
"Commander"




Joined: November 12 2006
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Posted: February 02 2014 at 18:42 | IP Logged Quote Pete37

Hi All,

Subject: Track-It TV

Has anyone got one of these on his Connie?





I'm thinking of installing one of these this summer. It will give me 300 satellite TV stations, WIFI, and telephone on my Connie regardless of where I am. Price is about $900 plus the TV receiver.

Pete37

Edited by Pete37 on February 02 2014 at 18:50


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Pats2nd Connie
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Joined: June 28 2013
Posts: 157
Posted: February 02 2014 at 19:56 | IP Logged Quote Pats2nd Connie

We have Trac-vision. Had to update the card to activate. Worked fine
in Nashville to Alabama. Then tried to update to local service and we
now do not get local channels.
Unfortunately, the bar is down for travel and we can't watch the Super
Bowl at anchor.

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Pete37
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Posted: February 02 2014 at 22:24 | IP Logged Quote Pete37

Hi Pat,

Subject: Track-It TV

Is Trac-vision the same as Track It TV? I guess from what you say service varies from place to place. Sorry you missed the Super Bowl.

Pete37

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Pete37
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Posted: February 02 2014 at 22:44 | IP Logged Quote Pete37

Hi All,

Subject: Mufflers

I'm tired of this mufflers subject, Bob is too and I'm sure that most of the forum members have also had it with the subject. It's unfortunate this is February. If this were May I'd just fire up my Connie, take it out and get a full set of sound level measurements. That would tell us what we've got.

That wouldn't give us anything about what the new mufflrs are but from my post of 1/29/2014 7:58 we've got a pretty solid case that the new mufflers are about 20 dB.

Then knowing what the difference is we can decide whether the benefits justify the price. As things are now we are just spinning our wheels.

Therefore, I suggest we drop the subject for now and get back to it in May.

OK Bob?

Pete37

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David Ross
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Posted: February 03 2014 at 00:50 | IP Logged Quote David Ross

I do not have Track It TV, formerly called Follow Me TV, on the boat but am familiar with it. I checked into getting one several years ago. They work well dock side or at anchor. The major name dome systems have another axis set up so they can work underway. Track It TV base price does not include the dish or receiver.

Since I have Dish TV at home I felt the better way to go was get another receiver set up for the home and bring it to the boat and buy another dish to install at the boat. There is no extra montly charge. I decided to do nothing. I do not watch tv underway, have not had a need for tv at anchor and our marina has tv hook up as most marinas do when we travel. If I was a live-aboard or spendt days at anchor I would consider a dish system. If you are under a covered shed you probably will have a reception and dish location problem. If you only want to use it away from your marina no problem. 

 

 

 

 

 

 

 

 

 

 

 

 

 



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Pats2nd Connie
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Posts: 157
Posted: February 03 2014 at 07:21 | IP Logged Quote Pats2nd Connie

Any satellite tv system needs a box with a service provider. Different
areas use different satellites. We may have to upgrade our tracvision.
Won't know until we get to ft Myers. Donna has spent hours on the
phone with dish reps and has given up for now. No big deal, there are
much better things to look at down here.

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Capt.Wayne
"Seaman"




Joined: October 31 2007
Posts: 63
Posted: February 03 2014 at 08:41 | IP Logged Quote Capt.Wayne

Hey,
My TV system started with Direct TV dish mounted on a piling next to the boat. they told me as long as the dish was stable it would be fine. Since then I've added Trac-Vision connected to the same receiver, mounted an HD dish on the fly bridge, added a HD receiver. We also have the Dish TV cabled to the slip with limited channels. Now with digital TV, I also can get local stations by just adding a digital antenna. The new digital TV's are Great, I mounted a 40" on the back of the helm seat.



 


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DMark
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Posts: 131
Posted: February 03 2014 at 08:51 | IP Logged Quote DMark

As an FYI. I'm going an entirely different direction that works
for us river boaters. I know how to piece a system together
that uses a cell phone to connect to the internet and drive a
digital TV via a roku box or apple tv. This gets me itunes,
netflix and many more options. its not over the air or cable
type tv channels, but that's not my interest when I'm on the
boat.

Its also a lot cheaper than the satellite stuff and ceel provides
plenty of horse power in my region. I'm in a rush now, but
will post more later.

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eshover
"Deckhand"




Joined: July 02 2011
Posts: 205
Posted: February 03 2014 at 11:14 | IP Logged Quote eshover

I have Follow-Me TV (Track-it). I have had it for six years.
My boat is on a private dock with no cable. The only issue
I had was a mounting location which would pick up signals
would dropping the signal. This was due to a high bank at
the foot of the dock with large shade trees at the top. I
"bow-in" and had a machine shop create a custom mount.
Pretty much now problems. Follow Me is made in Maryland
on Eastern Shore and is one of the more economical
methods of having Satellite TV on your boat. As
mentioned, no good underway but great at dock and
anchor (barring storms or high winds). It tracks pretty
darned fast and it uses any system. I like Directv and
simply pay for an additional box (listed as a bedroom on
my account). There is certainly a little more effort involved
with this system than the fully-auto dome type system, but
much less costly. Unless one has a family or a specific
need, I'm not sure why one needs TV underway. But many
people must feel they do and prefer the asthetic aspect of
the dome. And that's just fine. How one prefers to spend
their money is of no concern to me.

Emory

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Pete37
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Posted: February 03 2014 at 11:34 | IP Logged Quote Pete37

Hi All,

Subject: Track It TV

I'm not really interested in watching TV when underway. I'm usually busy watching my boat, other boats and the charts. But I would like to be able to anchor in a quiet cove and watch TV in the evening.

Track It TV claims that their systems work underway too in calm conditions. But if they don't that's not a big deal to me as long as they work at anchor.

I'd also like to able to get on the web when anchored out. For telephones, my cell phone seems to work in most places but a satellite link wouldn't hurt.

My marina has a cable TV setup but the station selection is not great and the cables don't work all the time. My initial thought was just to bolt a satellite TV antenna to one of the pilngs next to my slip and plug into it. I checked and there is a clear line of sight to the satellite. That's the cheapest thing to do and also a good starting point from which to get used to satellite TV. If I don't like it I can back out at little cost. This may still be my first step into the world of satellite TV.

Most of the better marinas in MD have cable TV so TV watching at most marinas isn't a problem. But in the small towns or anchored out there's no TV.

Two axis stabilzed marine TV systems are just too expensive to consider. The programming is going to have to be much better before I'll pay for the expense of the 2 axis systems.

Track-It TV takes advantage of the fact that the satellite is at a relatively fixed azimuth and elevation and therefore all you need to take care of is the azmuthal rotation of the boat. This reduces the cost by about 4:1 without much of any loss of performance.

The more I think of it getting a satellite dish mounted to a piling near my boat would be a smart first step. I could do that almost immediately at little expense. Once I'm used to it I can graduate to Track-It TV.

Meanwhile I can play musical chairs with my TV sets. The 19" set will go from the upper salon to the master stateroom. the 26" set will go from the lower salon to the upper salon and a new 50" set will go into the lower salon (if it will fit). After that's all set up and operational I can plug it into the satellite TV antenna.

Pete37

PS: Thanks Pat, Dave, Wayne, Dmark and Emory for your contributions. A lot of good info there and a lot of ways to skin the cat. I'm still a tyro in satellite TV. Incidentally, the expense of the Track-It TV, satellite dish, new 50" TV and 3000 watt AC/DC Inverter System is in lieu of new mufflers. I'll use ear muffs instead if I need them.

Edited by Pete37 on February 03 2014 at 12:03


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NautiKall
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Joined: January 22 2014
Posts: 73
Posted: February 03 2014 at 13:28 | IP Logged Quote NautiKall

Mark,

We were hosting a Super Bowl party yesterday, so I wasn't able to respond to your post yesterday at 2:40; I had other things to do.  Since Pete is now speaking for me, I thought I had better correct what he thinks I think.  It is refreshing to know he is now going to drop the topic.  Perhaps go back to his promised  "occasional post".

Your summary of concerns:  The Vernatone Mark II Dual Stage muffler is not new to Centek, It will only be new to me.

Centek Industries is a large corporation furnishing mufflers to the yaching industry for small yachts (200 HP) to mega yachts and cruise ships (2000+ HP).  They are an OEM supplier of standard products and do custom designs for special situations.  Walker and other muffler manufacturers make cheap mufflers for go-carts, lawn mowers, hot rods etc.

I have a brother-in-law who is an engineer for John Deere in Raleigh, N. C.  They are quite inventive in their top of the industry approach.  He said that they initiated a design project to develop their own mufflers for equipment where operators were on powered machinery for extended periods.  After several failed attempts at besting what muffler experts like Centek can do, they dropped the project.

Mufflers are not designed for a specific engine.  They are designed for sound wave canceling and sound absorption performance.  Generally speaking, the larger the chamber and the more baffling and changes in direction of the ehaust gas flow, the better they work.  The results are then measured and you get what you get.  Smaller physical size is a compromise with performance.

Pete's data, which he says I refuse know exists, is for 6V92's. I have 671 TI's.  Centek says attenuation is 25-30 db's, Pete is hoping for only 20.  By the way, 20 is a lot more than the existing 17.

My yard guy obtained a better pricefor the muffler than what I was able to get.  I,m going to proceed. I will also get the winter discount for labor.  A good winter project.   Stay tuned.  It will be two months or so before we know the results.

Bob K.


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David Ross
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Joined: January 02 2007
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Posted: February 03 2014 at 13:35 | IP Logged Quote David Ross

Another thought on dish tv. If you have a dock buddy (or can make a new friend) that has a dish mounted on a piling, you could share their dish and bring a home reciever on board. This could be a solution if your slip or boat position prohibits you from getting a signal. Also, if you have a dish mounted on the boat for cruising/anchoring, you could use the shared dish for your dock use and not have to be concerned about how your boat is positioned in the slip, covered shed, etc. I cannot get a dish signal from my side of our shed, even on a piling, but the boats on the other side can.



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Capt.Wayne
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Joined: October 31 2007
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Posted: February 03 2014 at 15:00 | IP Logged Quote Capt.Wayne

All,
Re:Direct TV,

My first satellite dish was on the piling nest to the slip, connected to the receiver on the boat. Three additional receivers were $5 a month now $6, and I found other boat owners were willing to buy their own dish and rent a receiver from me. The only drawback was they had to watch the same plan I paid for, but could watch a different channel than I watched. They were more than willing to pay $30 a month for the service, which made my cost $30 also. Everybody was happy. All you need is a clear view of the Southwestern sky


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David Ross
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Posted: February 03 2014 at 15:30 | IP Logged Quote David Ross

I'm going to check with two boat owners near our boat that have 6v92's in their 48' Califormian and 55' Sea Ray regarding engine noise. Other manufacturers might have used differant mufflers than Chris Craft (but may had more room allocated for them). That will have to wait until spring as I am still enjoying our winter get away. A lot of boat manufacturers in the 1980's and 90's used or offered as an option 6v92's (and 6v71's, for the 46' Connie owners here). It would  be interesting if any were able to come up with a way to quiet them. Forgetting the limited space situation, I wonder if two mufflers connected together would reduce noise and not cause any back pressure or other problem? If any of you know or come across another boat brand in your travels that have 6v92's or 6v71's check with the owner regarding engine noise and muffler/exhaust set up and report back.



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NautiKall
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Posted: February 03 2014 at 16:39 | IP Logged Quote NautiKall

Dave,

Good idea. It's important to know the date of manufacture of the boats that you do the noise check on.

My mufflers were installed in 1985. The tag on my mufflers indicates manufactured by Vernay Industries Yellow Springs, Ohio.  I suspect other Connies also had Vernay mufflers.

Search "Centek Industries" on-line.  There is an interesting history of two companies on parallel paths from the sixties.  Centek grew and grew and eventually bought out Vernay in January of 1994.  Prior to '94 Connies may have had Vernay or Centek mufflers. Also, since the 80's, Centek has advanced the science of muffler design.

I talked to a Centek design engineer again today.  He said they have specific data from dynanometer tests for noise evaluation on 671's and 692's.    He said he would try to find it and e-mail it to me. It might solve all the problems of what or who to believe.

Regardless, I have pulled the trigger.  The proof of the pudding is in the eating.

Bob K.


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DMark
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Joined: July 03 2007
Posts: 131
Posted: February 03 2014 at 16:40 | IP Logged Quote DMark

Bob and David,

Thanks for chiming in and the extra help and info.I remain
hopeful and understand that working through the issues and
options will take sometime. Happy to be helpful where I can.

Greg Shalk who owns Washington Marine near Cincinnati
knows Detroits pretty well. There's also an over the road
truck repair place close by with many years working with
Detroits who may also be helpful. I'l check in there.

A couple other resources come to mind as well.

Look forward to your next notes on the topic.

Mark

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