Westerbeke 7.6 BTD Vibration/Noise reduction

Discussion in 'Diesel Engines/Drives/Transmissions/Props' started by dtfeld, Nov 15, 2019.

  1. dtfeld

    dtfeld Water Contrails GOLD Sponsor

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    My 7.6 BTD runs well and puts out all the stable power I need, but its a little loud and vibrates through the hull that can be heard all the way up front in the vberth. So the issues are frame vibration and airborne noise.

    Vibration - The frame rails are rusted out and the isolators are 20 years old, so i suspect that this might be the source of the sound/vibration. However, the generator is lag bolted strait to the stringer, so I'm wondering if i should add another isolator under the frames, maybe as simple as a rubber pad. Lots of companies make these things for air compressors, and I would think they would work for this purpose as well.

    Can buy these locally, is something like this enough???

    Capture.PNG

    Airborne noise - since I'm going to almost have the generator out of the boat (trying not to but wouldnt take to much more to get it out), should I go ahead and add the sound shield. They are not cheap, but I think we'd use the generator more. Anybody add a sound shield aftermarket? I'm aware of the softsided versions, and that OK too, but its about the same price as the westerbeke metal version.

    Anybody add any additional vibration isolation and sound sheild? Pictures would also be helpful
     
  2. The Bill Collector

    The Bill Collector Well-Known Member GOLD Sponsor

    Jun 2, 2008
    Tacoma, WA
    450 Sundancer
    3126 Cat's
    We have the soft-sided version and it came with the boat so I can't comment on how effective it is. I have talked with others about it vs. the metal version for access and I can pass on most owners of the metal version tell me they are a PITA to work on the generator if needed. Our soft version can be removed in a few minutes if that long.
     
    dtfeld likes this.
  3. NotHerDecision

    NotHerDecision Well-Known Member PLATINUM Sponsor

    Jun 28, 2016
    Houston, Texas
    2001 Sea Ray 460 Sundancer
    2014 Seadoo 155 LTD
    2105 Seadoo 130 SE
    2013 Mercury Dinghy
    Cummins 6CTA 8.3L
    I’ll just say I am in a similar situation. I’m working on painting and detailing mine and already have new isolators and am going with the soft sound shield. I know it’s not super helpful but at least you know I’m on the same path as well as a larger exhaust.
     
    dtfeld likes this.
  4. dtfeld

    dtfeld Water Contrails GOLD Sponsor

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    NHD...

    How are you getting to the isolators? Are you pulling/have pulled the genny?

    I have pulled the starboard exhaust tube, the aluminum brace between the hatches and the aft vacuum generator. I have gotten the lag bolts out and the genny is loose. Trying to decide if this can be done in the boat or better to pull it.

    Im thinking I’ll replace the rails and the isolators, then see if that improves the vibration. I can see cracking and oil soaking of the isolators, and cant imagine that extends their life.

    Bill Collector...I like the idea of the soft side. If I can solve the vibration to the hull, I think the addition of the soft side enclosure would knock down enough noise to make a big difference to usability.

    07DBA407-2E47-4DD5-B670-956B5F7ABE9F.jpeg 8281B55E-C9DB-4A18-B39E-9FFFD32ABAE1.jpeg D7703D30-4A78-4212-B999-00E1F144516A.jpeg 20683CDF-4A7E-4341-9B4A-B903883809B2.jpeg
     
    Last edited: Nov 17, 2019
  5. dtfeld

    dtfeld Water Contrails GOLD Sponsor

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    In addition, going to do the following.

    Pull/service injectors
    Adjust valve lash
    New exhaust hose (one leaking late in the year)
    New raw water hose
    New coolant hoses

    If all goes well, add a soft sided sound shield.
     
    JVM225 likes this.
  6. dtfeld

    dtfeld Water Contrails GOLD Sponsor

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    Looks like the rail assembly includes the isolators. There is a picture of one but not the other...I’ll have to call about that. This would be nice, just have to remove the 4 main mount bolts.

    C5148DFF-F9AA-4425-9B45-2B51391F2CA7.png

    Dave
     
    Last edited: Nov 16, 2019
  7. dtfeld

    dtfeld Water Contrails GOLD Sponsor

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    I called Westerbeke, but could not get an answer to the question about the isolators being part of the left and right rail assembly.

    I ordered the rail assemblies, so we'll find out...
     
  8. dtfeld

    dtfeld Water Contrails GOLD Sponsor

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    The two stage muffler made a huge difference. If the new frame rails/ isolators get rid of the vibrations, I may wish I would have put in the gen sep, as the only thing left will be the water splashing out the exhaust.

    Maybe next winter:)
     
  9. fwebster

    fwebster Well-Known Member TECHNICAL Contributor PLATINUM Sponsor

    Oct 6, 2006
    Middle Tennessee ; Panama City Beach, FL
    1996 450DA
    3116 Caterpillars
    David,

    I have an 8.0 BTD Westerbeke and the first 5 years the noise was not objectional. Then we had an undetected seawater leakon the back side of the engine because it was totally invisible from the front or side and the seawater ran off the back of the deck the generator was mounted to......more about this later....

    At the same time, I was ready to do the valve service and torque the head. I've got a lot of diesel experience, mostly with small industrial type engines., just like the Westerbeke. It sounded like the Westerbeke generated a bit more diesel knock/clatter than Kubotas, Cummins 4B's, Cummins 6B's, Yanmars, and Perkins that I have in other applications. Since I was at 1000 hours, I decided to have the injectors pop tested and cleaned it necessary. The injectors tested to new specs. Since injector timing is largely dependent upon the valve clearance, I ran the valves then replaced the rusted frame rails and the isolators and the isolator's mounting hardware. The difference in noise and vibration was dramatic! The valve lash was corrected - fixed the excessive diesel knock and valve clatter. The Isolators were shrunken and cracked and as hard as plastic to boot. - really helped dampen the vibration.

    I considered a sound shield and a muffler change. The noise I was getting was not from the exhaust, it was engine clatter so I abandoned the new muffler idea until I took care of the needed maintenance items. I run a lot of boats for our dealer and have grown to hate sound shields. You cannot see the engine to spot leaks or things that are abnormal and checking the fluids is difficult. This can lead to undetected leaks that do damage if not caught in time and failure to check oil and coolant because of difficult engine access. If you are running someone else boat, you cannot "forget" the oil and coolant levels no matter how hard of complicated the access, so you grow to hate sound shields. This was going be my last resort to quieten my Westeerbeke.

    Bottom line for me in my situation was that my generator noise was valves that needed adjusting to control clatter and diesel knock and thew vibration was just due to the rusted mounting rails that didn't support the 8.0BTD ant longer and baked isolators they were more solid than soft so they transmitted the generator vibration rather than isolating it.

    I would encourage you to take this one step at a time and if you can avoid having to install a sound shield.
     
    dtfeld likes this.
  10. NotHerDecision

    NotHerDecision Well-Known Member PLATINUM Sponsor

    Jun 28, 2016
    Houston, Texas
    2001 Sea Ray 460 Sundancer
    2014 Seadoo 155 LTD
    2105 Seadoo 130 SE
    2013 Mercury Dinghy
    Cummins 6CTA 8.3L
    Mine is in the aft center near the transom so. My plan is to raise it up on 4x4 blocks and refinish the rails and replace the isolators as well as paint the mounting base. I should have this done in the next few months so I can report back then. I just take care of a few other boats that need attention over the next 60 days so I have to work mine into the schedule.
     
  11. fwebster

    fwebster Well-Known Member TECHNICAL Contributor PLATINUM Sponsor

    Oct 6, 2006
    Middle Tennessee ; Panama City Beach, FL
    1996 450DA
    3116 Caterpillars
    Josh,

    If your generator mounts like mine, at the rear of the bilge almost against the transom on the centerline, you can make it a one man job if you do it in halves. Remove 3 of the rail mounting bolts, then loosen the aft port nut and use the 4th rail mounting bolt as a pivot. You can lift and rotate the starboard side/end of generator out into the center of the bilge then put some blocks under the generator to support it while you repair the side of the generator that sites nearest the transom. When done with the aft side of the generator, rotate it almost back in place then block up the center of the genes with a 2X4 on end and repair the front of the generator.
     
  12. The Bill Collector

    The Bill Collector Well-Known Member GOLD Sponsor

    Jun 2, 2008
    Tacoma, WA
    450 Sundancer
    3126 Cat's
    As I said earlier, I'm not sure how much impact the soft shield has because I have never run the gen. without it, but I will beg to differ with Frank on the ease of inspection, full removal, and replacement of it. I have the soft shield and it has a velcro panel in front for an oil check and overall visual inspection of the front of the unit, this is easier than pulling the dipstick out. Complete removal is under 2 minutes as all pieces are just velcroed together and reinstall might take a couple extra to get the seams lined straight.
     
  13. NotHerDecision

    NotHerDecision Well-Known Member PLATINUM Sponsor

    Jun 28, 2016
    Houston, Texas
    2001 Sea Ray 460 Sundancer
    2014 Seadoo 155 LTD
    2105 Seadoo 130 SE
    2013 Mercury Dinghy
    Cummins 6CTA 8.3L
    Thanks Frank I didn’t think of pivoting it. I was just going to lift it on blocks and try to figure it out but once again you have a better idea! I’ll follow that advice for sure. My bottom rails are rusted on the bottom, not badly but I want to prep and paint them anyway. It was interesting to hear how your injector service and valve lash adjustment made the genset quieter. I will follow that advice as well. How did you remove the injotor without damaging it? Westerbeke has them priced like they are a rare earth metal so I don’t want to damage it.
     
    Last edited: Nov 17, 2019
    dtfeld likes this.
  14. dtfeld

    dtfeld Water Contrails GOLD Sponsor

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    I agree 100% on the approach. You can see my rails (especially on the backside) are completely trashed and I can see the isolators are shot, so I ordered new rail assemblies on Friday. I expect this to make a huge difference. I should have them installed next week.

    I have a local mechanic coming out first week of December to do the injectors and valve lash.

    I am doing new exhaust hose, coolant hoses, belt and fuel filter plus redoing fuel lines. I’m hoping for a drastic improvement after all this . I did the dual stage muffler last winter (big improvement as well)

    I’ll hold on the sound shield. When I asked the question, I hadn’t seen the really poor condition of the back frame rail, and based on all the feed back, expect the new rails will really fix the situation.

    If more noise suppression is necessary, sealing up the of engine room around the hoses and electrical might be a better way (if necessary at all).

    Dave
     
  15. dtfeld

    dtfeld Water Contrails GOLD Sponsor

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    "

    This is the info I was looking for...not as much room on my starboard side, but I bet it will give me enough room the turn the wrenches and access the things I need.

    But man it’s a tight fit for a 6’3” guy...
     
  16. fwebster

    fwebster Well-Known Member TECHNICAL Contributor PLATINUM Sponsor

    Oct 6, 2006
    Middle Tennessee ; Panama City Beach, FL
    1996 450DA
    3116 Caterpillars
    The injectors have a sealing ring between them and the head. If a reputable shop pop tests your injectors, they will come back with new crush rings on them. Most Westerbeke injectors have 2 ears on them with a bolt thru each ear that holds the injector into the head. Remove those small bolts and gently pry the injector out of the head and send the whole shooting match to the diesel repair shop for testing.

    Testing isn't expensive, but if a rebuild is necessary it will be several hundred $ per injector. If your generator is running well and not smoking, you probably only need to test and clean the injectors. My cost including, freight both ways, for testing and cleaning was $75.
     
  17. fwebster

    fwebster Well-Known Member TECHNICAL Contributor PLATINUM Sponsor

    Oct 6, 2006
    Middle Tennessee ; Panama City Beach, FL
    1996 450DA
    3116 Caterpillars
    Looking at your last photo, if you need more help with noise, I think there is room to glue sound deadening foam above and beside the generator. I think I'd try that before messing with a sound shield.
     
    dtfeld likes this.
  18. dtfeld

    dtfeld Water Contrails GOLD Sponsor

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    I agree. Let me get the rails installed and a good tune up done.
     
  19. fwebster

    fwebster Well-Known Member TECHNICAL Contributor PLATINUM Sponsor

    Oct 6, 2006
    Middle Tennessee ; Panama City Beach, FL
    1996 450DA
    3116 Caterpillars

    Mark,

    The critical component that will get overlooked when do your pre/post-run before leaving the dock or upon returning to the dock is the seawater pump. On the 8.0-BTD, when your family and guests are antsy to leave, I'd bet you that you and others with sound shields frequently do not check the seawater pump and plumbing for leaks on the back side of the generator engine. This pump is troublesome because the impeller cover is very difficult to remove and replace without leaks (it is a Westerbeke thing caused by a paper thin fiber gasket). We have 3 Westerbeke owners in this thread who are or have had to deal with leaks and rust damage from this area. If you have escaped the "fun" of repairing/replacing the generator support system, congratulations!
     
    HUMPH likes this.
  20. dtfeld

    dtfeld Water Contrails GOLD Sponsor

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    I agree. Let me get the rails installed and a good tune up done.
     

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