Butler Silencer

As you know from the other posts, my silencer rotted out and I ended up replacing it with twin welded Thrush turbo mufflers running end-to-end.  Well, the saga didn't end there.  The volume was better, but I noticed a decline in vacuum cleaning a home.  If I had to guess, I would say probably 50-60 cfm decline.

So, I tore it back out again and started over.  I first tried desperately to make the used silencer work, but math just wouldn't make it possible as it was just too long from all angles.

What did I do?  Well, first, let me provide a few details about the old silencer that rotted out so you can judge if I made the right decisions.

The factory silencer joined the elbow of the silencer to the blower's stub shaft by butting the pipes together and banding them with marine exhaust hose.  The metal was so thick that there was no way to crimp it down like standard exhaust tubing and this allowed full flow without any restrictions.  It was also a pain as it isn't the kind of hose you find in the hardware store.

This is that piece of hose.  I had to cut it away with a dremel in order to remove the elbow section as it was partially melted to the stub shaft.  It looks like a Mercruiser hose, which is pretty expensive and is sold only in rolls.  So, it would cost you another $250 just to get another 4 inch section.

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Then there was the silencer box....fully rotted out.  I had the exterior coated in undercoating about 5 years ago and had no idea how bad it was getting internally until a hole formed at the back end.  Once I inspected it, I could shove a screw driver through it easily.  It was that bad and as you can see, dropping it on the ground just exploded the rusty walls.



Also, did you notice what it really is?  A sound absorbing silencer wrapped in a thick metal box...worked really well, but not exactly a marvel of engineering and should be something that you could achieve with a universal silencer and a welded box packed with insulation.

I had 2 jobs pending and couldn't wait for a silencer to be shipped, I had to get something done and installed dual mufflers in-line in hopes of getting back on the road.  It worked, but it robbed me of vacuum power....not acceptable.

Today, I went to a truck supply store and bought the largest round truck muffler I could find that would fit in the space and operate on a 3 inch inlet.  It had 3 chambers in a pass-through design that would not rob me of flow...not sure if it would reduce much noise, but I wanted my vacuum back.

I pieced it all together and took it to my brother's boat shop to use his Mig welder...a Hobart 140, which was an awesome little unit for this job.  I welded it all together including that stub shaft off the blower (was a little worried that it might damage something, so I changed the grease and oil after).  I didn't touch the factory brackets in case I decide to return to a silencer and just welded a couple of supports to hold the weight.  I even added a nice downturn tip at the end....have to have a little bling right?

I had some vibration initially, but a couple of rubber isolators from the parts store and I was golden.  Now, I am not Terry, so don't expect my welds to be great, but I must say that they look pretty good.  I give credit to Hobart for that as my welding skill isn't known to be the best.....I have to buy one those things!







End result?  I loved the look of the install, but the real test was when I fired it up.  Vacuum was way up...actually tore my shirt when the hose sucked the tail by accident.   I was very pleased with that, but sound was also up.

According to the sound meter on my phone, at full speed, I was showing 87 db.  My Judson with the simple turbo muffler scores at 89 db, so I just turned my ultra-quiet butler into a Judson unit.   At least it is operational and I have the vacuum power back to full potential....probably will leave it that way until I forget how much "fun" this task was to complete.

Big question to everyone....what is the sound level on your machines?  A free phone app sound meter will get you the answer and I really want to know what other machines are scoring.

Mark, what is you butler running at with that ultra-quiet silencer....67 db maybe?  

It would be interesting to see what the levels are out there for comparison.  In my living room right now, my fridge and ceiling fan are showing 42 db and it is very quiet to me, so I am curious.

I'm betting that every slide in is going to score around 87-95 just from the motor's exhaust alone.  The blower noise is just secondary in comparison.  On a direct drive, I am guessing around mid-60's to low 70's, but it is just a guess.

Food for thought on sound levels

http://www.gcaudio.com/resources/howtos/loudness.html

I haven't yet read past the first section, where you said $250 for roll of hose, because I wanted to catch you before you blow that money on it.........because I think I can help you out.

So here goes.......
I know what a PITA that BellowsFlex/marine exhaust  type hose with the wire running threw it is to work with, cut, and basically impossible to clamp..............

Stand by, BRB to finish.........

I didn't go back to the hose yet...all welded now.

This hose isn't wire cored like a flex hose, it was more of a fiber reinforcement type of hose....really strong fibers. Even under the dremel, the hose would just shred instead of clean cut.

My brother told me that it was the Mercruiser hose by the looks of it and he can get me some at cost through his boat shop, but I didn't have time to wait for it.

Ok, well after reading the rest of your post, it sounds like you've already got it worked out? But if not, let me know because there is now a new type of vac hose now being made that's much much better than the stiff wire banned type of the old you mentioned......Light, actually flexible, ez to cut and clamp tightly and pretty inexpensive.

Here's what it looks like, kinda like giant vac hose, with big vinyl type screw on cuffs, but it's rated for 29" of vac made for strong industrial vac use.





Let me know if you want more info on it...

That is pretty interesting....what is the temperature rating. A blower exhaust can get pretty hot.

Off to clean a couple of store fronts....I'll find out if the noise is too high.

milspec6 wrote:That is pretty interesting....what is the temperature rating.  A blower exhaust  can get pretty hot.

Oh well shoot!

I thought you were talking about for the intake side of blower, sorry

That's what my post and this hose are made for really,......although I do think it would work for that also.

I've been using silicone type hose for my blower exhaust, and it holds up just fine to the 200-250 deg it runs.

That's my fault, I didn't describe that very well.

I was thinking about the silicone radiator hoses as well, they should be able to handle up to 300 degrees, but wouldn't offer much sound deadening value. Still, it would have worked to sleeve the pipes together...I didn't think of that soon enough for the first attempt on this task.

After cleaning a couple of store fronts, I am really surprised.

To me, it was simply too loud. I think I have been spoiled by the butler systems for far too long to realize just how loud a tm can be. It makes me wonder if I am really going to like having a slide-in.

At full speed, it was always at 87 dp. When I ran it at the upholstery speed (off idle), it sounded quiet to me, but it was still at 83 dp. Since sound doubles every 10 dp (70 is double what 60 is for example), reductions of just a couple of points are huge!

I am now thinking that all sliders are going to be 87-90 dp and the direct drives with good silencers in the 85-86 range. The numbers are minimal, but the actual level of sound is vastly different.

Now the big question is how much sound does that kohler engine make by itself? If you put that blower in a freaking gun safe, would you still be emitting upper 80's off the motor alone? My snow blower with an 8 hp Briggs runs at 90 dp with a new factory silencer.

This has changed my entire thoughts on how to quiet the future box truck. Being an aluminum box, sound will be amplified greatly if not dealt with. Not only does that mean the blower, but the engine as well.

Am I wrong here?

milspec6 wrote:After cleaning a couple of store fronts, I am really surprised.

To me, it was simply too loud.  I think I have been spoiled by the butler systems for far too long to realize just how loud a tm can be.  It makes me wonder if I am really going to like having a slide-in.

At full speed, it was always at 87 dp.  When I ran it at the upholstery speed (off idle), it sounded quiet to me, but it was still at 83 dp.  Since sound doubles every 10 dp (70 is double what 60 is for example), reductions of just a couple of points are huge!

I am now thinking that all sliders are going to be 87-90 dp and the direct drives with good silencers in the 85-86 range.  The numbers are minimal, but the actual level of sound is vastly different.

Now the big question is how much sound does that kohler engine make by itself?  If you put that blower in a freaking gun safe, would you still be emitting upper 80's off the motor alone?  My snow blower with an 8 hp Briggs runs at 90 dp with a new factory silencer.

This has changed my entire thoughts on how to quiet the future box truck.  Being an aluminum box, sound will be amplified greatly if not dealt with.  Not only does that mean the blower, but the engine as well.

Am I wrong here?  

No not wrong at all, you're on the right track, I believe. From my testing and experience making my TM quieter.....which I posted about on page 4 of my "upgrade/rebuild" thread. Check it out, I went from about 90 to the low 80's db with a much toned down 'pitch'.


Don't be convinced you have to live with a lot of noise with a slide in, if you're willing to do a little work. After some trial an error, I was able to reduce my noise output by about 10 db, which like you said is about double the sound, and not to mention, something that had never occurred to me.... Was in my mods, I drastically changed the 'pitch' of the sound/noise, which I think made an even bigger improvement.  By changing the 'pitch' of the sound from raspy to muffled, it made a huge difference in how Obnoxious (what I call it) the sound is.

Also, I ran my old engine without the blower connected and the sound output was about the same, within 1-2 db's.  But once I quieted down the eng., the blower noise become more noticeable (it was being drowned out by the high eng. noise), and I learned the eng noise what was what I really needed to tame.

BTW, everything I said in the above post^, was at 3,000 RPM's.

I think your on the right track. There's a difference between muffler and silencer. Muffled changes the tone silenced catches the sound and pressure then controls the release of sound and pressure. What you may try Rob is a longer exhaust past the muffler/silencer towards the rear of the van to change the harmonics of the sound. Talk to your brother about it. With a muffler shop I'm sure he's got some pieces of pipe laying around so try changing the length of exhaust even go larger as you get a foot or more from the muffler. Just a thought from shooting rifles and working for our Uncle.

My eyes are open on this sound issue, your input has been very helpful.

I think the butler van is going to stay the way that it is for now as it will be commercial back-up only come April, but I have to really create a good plan for the box truck....both engine and blower.

We used to use oil filters as a cheap muzzle silencer on our AR-15's. Just drill out the other end and thread it on....works pretty good, so there must be some good options for this truck.

I might end up using this used ultra-quiet silencer mounted beneath the box truck to help with matters, except I think the silencer will need to be closer to the blower for proper affect.

I think it might come down to using the largest piping possible, a good sound absorbing silencer, and good sound absorbing materials around and above the machine. I would love to get it below 80....that would be awesome.

I have some sound research ahead of me this week.

milspec6 wrote:My eyes are open on this sound issue, your input has been very helpful.

I think the butler van is going to stay the way that it is for now as it will be commercial back-up only come April, but I have to really create a good plan for the box truck....both engine and blower.

We used to use oil filters as a cheap muzzle silencer on our AR-15's.  Just drill out the other end and thread it on....works pretty good, so there must be some good options for this truck.

I might end up using this used ultra-quiet silencer mounted beneath the box truck to help with matters, except I think the silencer will need to be closer to the blower for proper affect.

I think it might come down to using the largest piping possible, a good sound absorbing silencer, and good sound absorbing materials around and above the machine.  I would love to get it below 80....that would be awesome.

I have some sound research ahead of me this week.

I might have a friend who has an extra Butler Silencer....wrecked van so he took out the system and has a bunch of parts....

I will text him today and see if he has one and who much he might want....He is in Detroit Lakes, MN

Mark Saiger
www.saigers.com

He does have one off a 97 Butler and GMC.


$200 and shipping and it's yours

Mark Saiger wrote:He does have one off a 97 Butler and GMC.


$200 and shipping and it's yours

Regular length van? If so, DONE!

milspec6 wrote:

Mark Saiger wrote:He does have one off a 97 Butler and GMC.


$200 and shipping and it's yours

Regular length van?  If so, DONE!

Just called Butler to confirm this. It should fit as they only make One silencer. This was off an extended but should work. Do you have your brackets yet? Need anything else with it? Would be best to call me later and can get you all the contact info for my friend with this

218-259-9099