New Advertiser - K&B Supply - Gas Exhaust Silencers

Discussion in 'Announcements & FAQs' started by CSR_Admin, Oct 16, 2009.

  1. Jimmy Buoy

    Jimmy Buoy Active Member

    Dec 3, 2008
    Sarnia, Ontario, Canada
    340 Amberjack
    twin 8.1S 370 Hp + 4.5 Westerbeke Genset

    "Easy to install"? I tried briefly to remove the rubber exhaust hose from the engine's riser and it's really really stuck! They have only been on there a little more than a year too. Mind you, this was during the winter and even though it's inside, the temps were still around 40. What's the trick to removing exhaust hoses?

    Also, the storage shop's mechanic cautioned me that I'd lose quite a bit of WOT RPM's with the silencer's exhaust flow restriction since my 496's really like to exhale freely. Kinda gave me pause...

    I've run into some prop issues (they are out being dialed in at the present), so I don't want more than one performance variable done at a time. Once I know what the engine's normal performance is with the props I will then look at doing this "EASY" install - that is, if someone wants to share how to make it easy.

    Sorry guys - no feedback till then!
     
  2. Jimmy Buoy

    Jimmy Buoy Active Member

    Dec 3, 2008
    Sarnia, Ontario, Canada
    340 Amberjack
    twin 8.1S 370 Hp + 4.5 Westerbeke Genset
    OK - The silencers are now installed (for the 2nd time):smt013

    After having some degree of difficulty getting in touch with K&B with additional questions, I finally got to speak with Dan last week. :smt038

    The first installation I did about a week ago was not fully successful:smt009. Exhaust noise was absolutely reduced BUT I found that both engines were stumbling at idle. I could hear some missing, I could see it on the wavering sync gauge, and I could hear one transmission chattering at idle speeds from the low or varying idle. The smell of raw gas was also noticeable - all previously not evident. :smt089

    I then removed the silencers :smt017 and the engines went back to idling properly so I was considering returning the 4 silencers for a full refund as promised. :smt100

    One more try contacting K&B! :smt014Dan happened to answer the phone number listed on the CSR Ad this time and when I informed him of my issues, asked how far his product was from the tip of the engine's risers. "About 1/2 inch", I replied. There was no additional room from the riser to the 90 degree fibreglass bend and tube to the water lift mufflers - there was just enough room and that was it. Dan said that was the problem. The Silencers were much too close to the exhaust risers and water was spashing back into the exhaust manifold at idle. The silencers must be further away from the risers.:smt115

    The only other area in the exhaust lines with a 4" rubber hose was where the two fibreglass tubes connect to each water lift muffler. I had to cut about 4" off the fibreglass tubes to make room for the silencers, but they went in fairly easily.:thumbsup:

    The results. PERFECT. :wink:Idle showed no signs of stumbling even while in gear (while tied to the dock). Thru-Hulls were even quieter than after the first installation. A quick sea trial resulted in the same degree of noise reduction as with the first attemped installation and the same 50-70 RPM loss at WOT. (minimal in my opinion)

    Looks like I've now got the product doing what it claims to do! I'll be monitoring the engines for the next while just to make sure there aren't any other glitches - but confidence is high! :grin:

    Sorry - No Video - No db Meter, just me and two other fellow boaters that all say the sound reduction is real and substantial. Thanks Dan!
     
  3. trit21

    trit21 New Member

    Dec 16, 2007
    Live, Orlando: Boat, Ft. Pierce
    See signature
    See signature
    So if you have an RPM loss doesn't that mean you are getting worse fuel mileage or using more fuel to push the boat as before without the silencers? Wouldn't that also mean you are creating more back pressure?
     
  4. Jimmy Buoy

    Jimmy Buoy Active Member

    Dec 3, 2008
    Sarnia, Ontario, Canada
    340 Amberjack
    twin 8.1S 370 Hp + 4.5 Westerbeke Genset
    I agree! There will be more back pressure with the silencer installed. The question is how much? If my WOT was 4470 and is now 4415 that is only a difference of 1.2% which is acceptable in my opinion. It is also safe to assume that at any speed, this restriction will also have a negative effect on fuel consumption - again though, minimal.

    Most likely your own car whatever the model, would benefit from a free flow exhaust system (more power, higher top speed, better fuel economy) since auto manufacturers put a more restrictive system on the car to reduce exhaust noise. Why haven't we all ditched the stock exhaust then??? We don't really want the noise - that's why.

    In my case, I am simply willing to pay an apparently small price for a considerable increase in cruising comfort.
     
  5. trit21

    trit21 New Member

    Dec 16, 2007
    Live, Orlando: Boat, Ft. Pierce
    See signature
    See signature
    Actually we haven't ditched the stock exhaust systems on cars because it is illegal to do so I believe, noise ordinances and pollution control devises are in the exhaust I thought making it illegal to remove such devices. Cars and boats are totally different devices. Cars will cruise at 1800-2000 rpm getting 30mpg at 80 MPH. Your boat has to make alot of power to push all the water along to cruise. Marine engines work HARD to cruise while cars engines do not work nearly as hard. By restricting exhaust output, you are limiting your engine output thereby making your engine work harder to push the same amount of water and cruise at the same speed.
     
  6. GDDMD

    GDDMD New Member

    8
    Aug 21, 2010
    GUNTERSVILLE, ALABAMA
    200 bowrider 1992; 240 sundeck 2005
    5.2 liter mercruiser; 350 mag mercruiser w/ bravo III
    I have a bravo III on a Sea Ray 230 bowrider, the engine has 320 HP. Will the angled tubes with the built in muffer work , fit, and be affective on my boat?
     
  7. Jimmy Buoy

    Jimmy Buoy Active Member

    Dec 3, 2008
    Sarnia, Ontario, Canada
    340 Amberjack
    twin 8.1S 370 Hp + 4.5 Westerbeke Genset
    I don't think there is any free space in your exhaust system to fit the mufflers (assuming you have "through hub exhaust" vs "through hull exhaust).
     
  8. GDDMD

    GDDMD New Member

    8
    Aug 21, 2010
    GUNTERSVILLE, ALABAMA
    200 bowrider 1992; 240 sundeck 2005
    5.2 liter mercruiser; 350 mag mercruiser w/ bravo III
    Dan,
    Tried to reach you or your company about these SS elbows for mercruiser with built in silencers for $138, but getting no response. Are you still in business. Do you still build and sell these silencer components for mercruiser bravo III 5.7 v8 engine in a sea ray 230 yr 2003? If so, please respond, as I have about given up on being able to reach kb performance at all! I will buy them immediately, if they are still available as advertised.

    Mike (GDDMD)
     
  9. Jimr810

    Jimr810 New Member

    1
    Aug 18, 2012
    MN
    2005 MC PS 197
    350 CI, Indmar MCX
    Dan, I have a 2005 Mastercraft PS 197 with the Indmar MCX engine. I'd like it to be even quieter since I ski on a public lake early in the morning. Will the K&B silencers fit?
    Jim
     
  10. Jim, I wouldn't hold your breath waiting for a answer.


    PS, Welcome to CSR. :smt001
     
    Last edited by a moderator: Aug 20, 2012

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