Posted: 4/11/2014 7:36:33 AM EDT
I'm not a mechanic so please don't make too much fun of my ignorance. 
Can someone explain why my Silverado' 5.3L V8 engine bairly makes any noise but by 4000w generator is loud enough to wake the demons from the center of the earth? Can I get a truck muffler mounted to this thing?
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From most significant to least.
- The fan on a small air cooled engine makes most of the noise, direct drive, no clutch. 5.3 fan is either electric or clutch and doesn't spin all the time or as fast as the engine. - Eghaust is next but with a decent muffler not so much - RPM, direct drive gen most likely 3600rpm all the time, 5.3 600-800 with you standing beside it. When the 5.3 revs it makes more noise. - Air vs water cooled, water cooled thicker castings and water muffles noise. - 5.3 truck cab is insulated. The newer inverter generators are not direct drive and so the rpm is much lower a low load/most all the time=much less noise. |
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All of that makes sense. Its a Cabela's "Champion" generator which I knew isn't quiet but I really only use it for power outages which are rare. All I need to run are my freezer fridge and furnace blower in the winter and perhaps a charger or two. The plan is to use oil lamps for light. One of my concerns is that noise could attract undesirable attention. I've been trying to imagine some sound absorbent panels I could set up around the thing to help absorb the noise a little. As dumb as it sounds I was thinking about some heavy moving blankets draped over some kind of steel or plastic frame with plenty of air movement for cooling and no insulation on top. I don't care about noise going vertical its the horizontal noise that will be the easiest to hear. Am I smoking something? Is noise reduction achievable? or should I forget about it and invest that money in more 55 grain in case of aforementioned 'undesirable attention'. Thanks for the replies! |
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Quoted:
All of that makes sense. Its a Cabela's "Champion" generator which I knew isn't quiet but I really only use it for power outages which are rare. All I need to run are my freezer fridge and furnace blower in the winter and perhaps a charger or two. The plan is to use oil lamps for light. One of my concerns is that noise could attract undesirable attention. I've been trying to imagine some sound absorbent panels I could set up around the thing to help absorb the noise a little. As dumb as it sounds I was thinking about some heavy moving blankets draped over some kind of steel or plastic frame with plenty of air movement for cooling and no insulation on top. I don't care about noise going vertical its the horizontal noise that will be the easiest to hear. Am I smoking something? Is noise reduction achievable? or should I forget about it and invest that money in more 55 grain in case of aforementioned 'undesirable attention'. Thanks for the replies! I have the same one and it seems quiet to me, you can build a shed. http://ps-survival.com/PS/Electrical_Power/How_To_Construct_A_Soundproof_Generator_Shed_2001.pdf |
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Quoted:
From most significant to least. - The fan on a small air cooled engine makes most of the noise, direct drive, no clutch. 5.3 fan is either electric or clutch and doesn't spin all the time or as fast as the engine. - Eghaust is next but with a decent muffler not so much - RPM, direct drive gen most likely 3600rpm all the time, 5.3 600-800 with you standing beside it. When the 5.3 revs it makes more noise. - Air vs water cooled, water cooled thicker castings and water muffles noise. - 5.3 truck cab is insulated. The air intake to the carb or throttle body also accounts for quite a bit of noise, particularly when the engine is working hard (i.e., near full throttle). Car manufacturers put a lot of effort into quieting it down. Speaking of working hard - most of the other noises mentioned above also increase whenever the engine is producing significant power. You don't hear it, because (1.) you're inside the cab, and (2.) wind and road noises tend to mask it. |
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Working in the Army Reserve motor pool back in the 1990's, I chatted with some of our Generator Mechanics at the time.
To cover some of the noise of the large diesel generators the army would build an open top sandbag bunker around the generators. The idea was that the noise went straight up instead of out to sides. |
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This guy has it figured out:http://www.alpharubicon.com/altenergy/gensetquiet.htm
What this does is use a muffler designed for a much larger engine to muffle the small engine on the genny. If one was to use a smaller muffler to accomplish this task, the back-pressure might be too much for the little motor to run right. BUT, with the way over-capacity muffler used, the back-pressure doesn't rise much because the exhaust gas outflow is not restricted too much. IOW relatively huge muffler = very small increase in back pressure. With the flex hose used, it might be possible to mount the muffler to the frame of the genny. A smart person would rig up some stout wire heat shielding, and not mount the muffler near any heat-sensitive components, nor block air flow to the genny. Placing a hot muffler in way of the intake of the genny's cooling fan would be a very bad idea. |
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Quoted:
Working in the Army Reserve motor pool back in the 1990's, I chatted with some of our Generator Mechanics at the time. To cover some of the noise of the large diesel generators the army would build an open top sandbag bunker around the generators. The idea was that the noise went straight up instead of out to sides. Might also have been SOP to protect the gennys against close hits. Two birds/one stone. |
You could put the generator in a small house like structure with baffled openings for air flow. I would advise you to have a forced air cooling system setup- Think a window fan hooked to the generator output so anytime the generator is running so is the fan. If the entire inside and the baffles were lined with thick rockwool insulation you would quiet that thing down significantly. As an added bonus in the winter time it would likely keep it from getting too cold and hard to start 
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^^^ Yep.
Taking a piecemeal approach to quieting down a generator can be frustrating. After you get the engine exhaust quiet, you discover how much noise is coming from the engine valvetrain.
Get the valvetrain quieted down, and you discover how much noise is coming from the air intake.
Compare that to an enclosure - which really doesn't care where the noise is coming from. Also, unlike modifying the generator itself, any effort and money you spend on building an enclosure isn't wasted if you change generators - Your new generator gets the same benefits from the enclosure as your old one did. If you own multiple generators, they all benefit from the enclosure. |
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I am not that familiar with the specific generator you mention but in lots of reading about lots of standby generators for houses and what not you will probably run across some muffler options. The larger generators tend to be built better and the ones made to sit outside already have a sort of enclosure. I recall one fella on a website with one for sale, he had one for his house and then moved, and he always mentioned that his had the hospital muffler option which apparently was a step or more beyond the stock muffler. |