Will a Car Muffler Make a Generator Quiet?
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- čas přidán 3. 06. 2020
- Recently picked up this generator which had a car muffler installed. I tested the sound output in decibels with the car exhaust and the stock OEM muffler. Does a car muffler make a generator quieter?
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I’ve done something similar to this, but you MUST use a motorcycle muffler instead of a car, especially for single cylinder engines, because they’re designed for the constant 100-0-100 pulses of the exhaust, instead of the continuous gas flow from a multi-cylinder car. I personally used a stock Honda grom muffler and it was VERY quiet, and they’re not too expensive. Just make sure you don’t have a hole in the system 😊
Hole in muffler AND Loose Muffler Bolt
I'm disappointed he didnt run the With Muffler test again with the bolt tight and hole covered
Excellent point about the pulses. Thanks!
That comment should be pinned. Good info.
The car muffler is also just oversized. It's not going to damp the exhaust pulses well because there won't be smooth flow/consistent pressure through it. Like putting a 3" exhaust on a 4cyl car. A 125cc motorbike muffler like you used sounds ideal since even if this generator engine is 200cc or so it's only running at 3600rpm.
@@rwbimbie5854 He is not the sharpest tool in the shed when he touched that weld he was grinding on to see if it was smooth, was when I clued in thats not recommended LOL.
If anyone wants to mount an automotive muffler to a generator, it needs to be supported by the engine/alternator assembly, not the generator frame. Everything attached to the engine needs to be able to move as one unit because the engine and alternator are mounted on rubber isolators. If you don't, either the muffler bolts will vibrate loose, or something will break. Maybe both.
Or use a flex section of pipe...
@@OmegaZero1242 the spiral flexible exhaust pipe (i assume this is what you're referring to) isn't meant to be continually flexed, it's meant to be easily bent to the required shape. If it's continually flexed, it will loosen up and leak
A rubber hanger mounting on the exhaust would have been fine; it's exactly what is done with car exhaust systems, and why it was welded direct to the frame, I've no idea (and it ought to have been joined to the standard muffler using a U-clamp).
Metal should never touch metal unless properly secured. Learned that in auto tech school
Exactly right, the muffler needs to be supported by a bracket and the engine vibration isolated by a flexible pipe of some sort. Sure the metal flex will slowly wear through but better than having the exhaust "manifold" (a 3/4" inch of threaded black iron gas pipe) vibrate and crack the head. Another factor: much of the B&S noise is from the internals which sound like a #10 soup can full of nuts and bolts rattling. You can only do so much to quiet these engines.
Another option is to move the generator farther from the using device (which might be a transfer switch of some type to power your house in emergencies). This also gets the exhaust fumes and carbon monoxide farther away, too. The trick is that a 40' power cord is expensive, but what's your life worth?
In 1990, I built a portable 2x4 framed, insulated wall system on two sides to deaden and direct the noise in a line between my house and my neighbor's. It worked but in the end I saved up for and bought a permanent natural gas all-home 20kw automatic generator. While a step up, I wouldn't discourage those who are shooting for a similar level of protection at the cost of these smaller 5kw construction type generators.
Something to note about sound: the decibel measurement system is a logarithmic system, meaning, it isn’t a linear system (like inches or liters).
What this means is: for every 3 decibels increase, sound pressure (or perceived volume) DOUBLES. So a 6 decibel increase in your measurement means that the sound pressure has increased 4 times.
Yep. 6db difference, 4x louder. That made a SHIT ton of difference.
I hate everything logarithmic, such a headache!
@@EgillBjarniHelgason If you didn't have logarithmic scales for such things then all but the very highest levels would be squashed over into a tiny part of one end of the scale. Also, out perception of things like the loudness and brightness of something is physiologically logarithmic. Human hearing goes from about 0dB to 120dB, which is a range of loudness of 1:1,000,000,000,000.
"Noise above 70 dB over a prolonged period of time may start to damage your hearing. Loud noise above 120 dB can cause immediate harm to your ears."
so the conclusion form the video in this circumstance the car muffler made it safe to stand at that distance without ear protection
Except we hear logarithmically as well. So a 3 dB doubling or 6 dB quadrupling of pressure sounds only slightly louder to us.
Just a little tip. If you decide to use steel water pipe screwed into the block to mount a muffled remember the pipe is a lot thicker and won't disperse the heat and can burn out the exhaust valve. It has happened.
Try a sheet of plywood leaned against the generator to see if you can reflect the sound towards your neighbors and lower the level at your meter.
A sheet of 2021 plywood is more expensive than a 12 mufflers!
🤣🤣🤣
Mine poisoned my 8 year old black lab. This little boy dog came into my hands with one eye. He was athletic, robust and healthy. As the porch light came on, he split the light for missing eye to good to catch a tennis ball. I am fighting a decade of lumbar fusions (4) and have my 13 epidural coming next Tuesday. Bad elbows caused me to use a plastic throw stick and boy he could catch up to 11 in a row. Slept on my feet all night and napped under the tree shade while working on my truck. One day, he crawled to the fan, then laid belly down on the cold March ground, couldn’t catch his breath. Lady VET told me all organs were shutting down & eyes were blood red in 10 minutes. Gone in 1.5 days. A hell of a way to remember a birthday, my 60. Miss you buddy! Damn neighbor from another country. It ain’t a muffler story but real quite!
Worked a motor cycle dealer, expansion, compression, reduction in exhaust with a hole the size of a nickel. Then quite.
You are the reason I'm glad I don't have neighbors.
Fuggin lol rite mate
Imagine welding up a muffler on a generator just to have the guy you sell it to make a video of him removing it
Imagine whirled peas....
And another video of him putting it back on when martial law is declared and a roving band of criminals is looking for where the generator noise is coming from !
That vid could have easily been 2mins long.
I wouldn't really call that welding. More like atypical novice application of molten metal as an attempt at joining 2 metallic items. Key words are novice and attempt.
😂
The engine manufacturer usually makes a "quiet" generator muffler that doesn't always come standard on store bought generators (I know, I was shocked too). That's usually the best option to reduce generator exhaust noise over all the homebrew methods. It will never be whisper quiet because much of the noise from a small air cooled engine is not from the exhaust.
Granted whoever did that conversion did it poorly, a couple points: whole test is invalid because you ran the test with car exhaust with a hole upstream of the muffler (sorry, your block of wood wasn't doing anything) as well as a loose muffler bolt. Both conditions were repaired for the stock system test. Even with that severe handicap, since the decibel scale is logarithmic, the stock system was FIVE TIMES as loud as the system with car exhaust. Done with proper rubber isolation, a good drain, and considerations for heat, that system could probably perform far better than it did here. I think we could expect a functioning system to achieve levels of 10 db quieter, or reducing perceived sound by 90%. I'd call that worth it.
That's exactly what I thought we he mentioned the hole. I paused the video and looked for a comment like yours. As a welder, I've seen decent welds fail to seal exhaust leaks, that block of wood probably just made it louder over all by adding vibrational noises and raising the pitch of the sounds coming out. I car audio, you have to double your power output for every 3 DB of sound. 3 decibels of sound pressure is a big difference in loudness. This was a neat experiment to stumble on and make a video about but really would have benefitted from some extra research. Still a great video and I appreciate everyone involved. I would honestly consider putting a decent 3 chamber muffler on a larger engine like this. It might reduce performance but it couldn't be too bad. Id want to see power output before and after
I agree with you on how the test was flawed but that is not how logarithms or decibels work.
Don't forget the intake as well... there is a boat load of noise from that end too. As others have pointed out there is the mechanical component to the noise. I agree with you on your points though.
i immediately thought the same way before i saw the hole in the original muffler. glad im not the only one who sees that if done correctly it could be a major improvement. the larger the space for the sound to get baffled the more silent the exhaust will be. poorly executed but proof of concept is there, decibels work differently than most people know( i worked 7 years in a small engine power equipment shop, i know what these things sound like with and without mufflers) i think if done correctly with the proper back pressures that the engine is built for this could work alot better. just look at how much a rifle suppressor can muffle a gun shot!
@@tokimcbongrip8751 As someone who's experienced a blown exhaust gasket on a car, it'll turn a quiet 1.2 litre engine in an open piped Harley Davidson. So yes that hole is gonna make loads of noise, and a bit of rough wood held over it is irrelevant.
Hole in the exhaust when you're testing volume? Sorry man, huge source of error there.
He isn't testing volume, he's testing whether the car muffler did anything to lower noise and found out that car muffler + bad stock muffler is still quieter than good stock muffler. Having a good stock muffler before the car muffler would only have widened the gap. Though for such small engines, just having a longer smaller exhaust pipe to give the exhaust flow some inertia would achieve much of the same goal.
@@teardowndan5364 You basically said "he's not testing for a volume difference, but for a volume difference"
@@ilpatongi He was testing for a confirmation or rebuttal that it made a difference, not numerical accuracy. 3dB, 5dB or 7dB in favor of tack-on muffler makes no difference, all the numerical values are needed for is to confirm that he's not imagining things.
If he was worried about accuracy, he'd be using a calibrated directional SPL meter instead of a phone for measurements.
@@teardowndan5364 And again, a long comment to say the same thing OP said...
@@ilpatongi Think you may be misunderstanding the experiment. The hole is mostly irrelevant in this situation. He is just looking for a difference in general. The hole only makes his point more so.
I agree that a motorcycle type muffler would be a better mod.
But actually the loudest noise of a portable genset is vibrating metal. Add more isolation to the mounts and the noise can drop a LOT. Enclose it with baffles while directing air and exhaust flow and you’ll make it practically disappear.
You do realize that every increase of 3db is a doubling of sound pressure, right? (logarithmic, not linear) So, 5db is 3.16 times louder! (6db would be 4x, 9db would be 8x, 12db = 16x... Car muffler was doing a lot, actually. :(
we perceive a doubling in volume at +10db though, so while you are correct we wont hear it that way.
@@DracolegacyOfficial Pick a level as the reference, and +3db is a doubling of power, but you are correct and I stand corrected... 10db or 10X more power is required for the human ear to 'perceive' a doubling in loudness. :)
@@scottdebruyn7038 What
Anything way though, the reduction of pressure is the big on for your ear drums. You may not hear the diffrance but it's like standing in a node, the pressure could be felt if your ears havnt been abused by high pressure pulses and loud sounds already. Based in what I've learned at least
@@michaellandon1960 Yeah... Wild, huh?
As soon as I saw that exhaust leak, I knew it wouldn’t be an accurate measure of noise...and then you changed out the _entire_ stock muffler which did not have the original leak, that ended the entire shebang for me. (Fwiw, a small rough piece of wood held by hand will do _nothing_ for noise abatement).
seriously, I was really wanting to see what happened... then the exhaust leak was shown... does this guy not understand how mufflers work? they need to muffle the vibrations BEFORE they go into the air. then he said he was going to block it, my immediate thought was "grab some muffler tape that'll at least not give terrible results". but no this guy grabs an irregularly shaped piece of wood and just holds it against the hole. You think that's going to create a seal?
Yeah....couldn't agree more.
Well you can hear by the tone of his voice that the video would be biased against the muffler so when I saw the piece of wood being held next to the hole I could gauge his IQ level.
The issue is you guys lack the fundamentals knowledge of….well anything pertaining to this.
Generator engines run at 3600 rpm to produce 60hz electricity.
An engine is just loud at 3600 rpm. Especially one that exhaust directly into the muffler. Strapping an oversized muffler to it takes it from loud to still loud.
Go out and rev your car up to 3600 and you’ll find it’s relatively noisy and that’s with an engineered exhaust manifold, resonator, at least 1 catalytic converter, multiple feet of exhaust pipe and a muffler engineer specifically for that vehicles engine.
The 3 dB rule, look it up if you don’t know it. That muffler did quite a bit of noise reduction.
Not to mention the old one had a hole in it, and the second one didn’t. Also same reason why I don’t think this test is very accurate
@Joe _ No it's 3. it's more complex than that actually as the decibel value is a function of a variety of environmental factors. (air pressure and distance) but 3 is roughly "double"
It's more complicated than just 3dB is a doubling. That works if you're measuring power. Perceived loudness doubles at 10dB and measured sound pressure doubles at 6dB.
So, yes, the car muffler roughly halved the measured sound pressure and reduced the perceived volume by 1/3-ish
@@garrisonsan Yep on the numbers here. Most don't know.
@Joe _ nope. every 3db is double
A large amount of the noise is actually mechanical.
Sounds like a huge exhaust leak I mean look at the welds lol
Yep... It's a Briggs. Desiged to 100th of an inch and precision machined to tenth of an inch tolerances.
Valve-train can be noisy
True, my old diesel truck it’s pretty quiet as it is, the noise it has is just from the engine & the mechanical side of things.
Exactly what I came here to write !
Used this czcams.com/users/postUgkxOTeIs0vv4_9B5hsmnLsk9r930uDQLu_Y for the first time this weekend. It powered everything in my Rpod camper plus a small heater for my friend’s tent. I love the remote start!This works better than my two Honda 2000’s Very happy with it. Just make sure to do a proper break in. The instructions don't talk about it. Look it up on CZcams there’s some good videos on it.
One factor that needs to come into play here is how loud the generator is with a load placed on it. The generator is going to be burning more fuel per engine cycle to maintain 3600RPM with a few thousand watts on it. This, in turn will make more explosive energy in the exhaust system, which creates the noise. It would be good to run this test again with maybe two 1500-watt space heaters plugged into the generator for a simulated load. The automobile exhaust muffler, I imagine will really show an improvement, as it's designed to be more effective with higher exhaust pressures.
Your statement would be valid if you knew that inverted generators are the engines designed to vary idle speed with load demand. The generator shown in this video maintains its rpm whether or not a load is placed.
@@tlc5343 That's the point. To maintain the RPM under load it needs to get more fuel per revolution, i.e. more exhaust pressure, what audvidgeek was talking about.
@@MarekLewandowski_EE Exactly. Engines don't burn fixed amount of fuel per rpm. It depends on how hard it is to hold that rpm. If you'd ever had a car with a cold intake or just sports exhaust you'd know that holding 3000rpm at standing still is nowhere close the sound level of engine accelerating @3000rpm. That is why also revving engine on place will make more alot more noise because at the time of full open throttle engine is burning alot more fuel and is louder.
@@tlc5343
The op explicitly stated maintaining the rpm. They were not confused.
@@tlc5343 Get absolutely fucking destroyed by these legends
Fix the hole properly, support the muffler with a rubber mount, have the exhaust blow outwards, not down, and correct that loose mounting clamp, then test.
Second on the rubber mount. A lot of people don't realize how loud vibrations can make things.
@@Razzman70 Aye. A good example in my mind are the fans we have around the house. Even those cheap dollarstore rattletraps. Spending a few minutes playing around with some rubber padding will make your home THAT much more quieter.
It is amazing what all a busted bicycle inner tube can do.
@@FroggyMosh I like bubble wrap, the stuff comes in the house all the time. Fold it double & sit the fan on it, don't even think about it. Only go buy some rubber padding when girl friend says "make that neater or else!!!" For quiet fans I like 2 speed USB powered fans.
Agree totally, I also think the muffler exhaust is too big for the engine & should have been reduced. Someone commented it should have been a motorcycle muffler which is actually designed for the same type of exhaust pulsations, so all your commnts plus the right muffler.
I saw one running in southern Mexico once with a motorcycle muffler and it's the quietest generator I've come in contact with.
Especially a 2 stroke one like it’s used to quiets a 2 stroke dirt bike and those things are loud asf with out a silencer on them
Every 3dB is *double* the sound energy emitted. This is diluted through a hemisphere of air separating you from the generator. The energy reduction is defined by the equation (2πr^3)/3 where r is your distance from the generator. While you don't perceive a reduction of half it's still significantly less with the muffler despite the huge exhaust leak in the original muffler.
absolutely correct, 3.01dB to be exact. At almost 6 dB louder without the muffler, it is effectively twice as loud.
NERD!!! - Ogre.
Yep! I saw the 6dB change and thought that was a pretty impressive result. You wouldn't notice it right up next to it, but your neighbors would certainly appreciate the difference.
@@jaydee3730 Wouldn't that be louder by x4?
@@jaydee3730 4x louder
I've grinded and welded literally millimeters from a fuel tank, watching you remove the fuel tank for working on this gave me a good chuckle.
I've been saying this forever. Put an oem auto muffler on everything you want quiet (especially boats and gennies).
Can i put it on my wife
Jimmy L. Might need a baffle to
Does it work on women?
will it work on my husbands huge but crack
@@cessnadriver9885 if you've got the room use the resonator too
Add an inline exhaust resonator pre-muffler. The standalone resonators will give it a deeper tone but they work WONDERS for quieting down an engine without a full cat.
I agree, a resonator pre-muffler would be much quieter especially in a smaller diameter tubing. He should have no more than a 1.5" pipe, and even that's over kill for that low output tiny engine. My dirt bike for example makes 2hp per cubic inch of displacement and has a 1" exhaust.
As people have been talking about in many CZcams videos recently, a muffler is not the only serious component to car exhaust in terms of noise. The other most important component is the resonator, which shapes the sound, before it gets run through the baffles and chambers of the muffler. I think that without both components it's not a fair comparison.
Put a much smaller tailpipe on it will make the muffler more effective. The muffler will actually act like a resonator.
Somebody who gets it. It really baffles me.
@@williamodell9955 GET IT?
You’re using the terms resonator and muffler backwards.
-A muffler uses sound absorbing packing and or baffle plates to reduce or “muffle” overall sound energy over a wide frequency range. Hence the term “muffler”
-A resonator uses mathematically tuned sound chambers to produce specific resonant frequencies that cancel out the natural resonance of the exhaust (commonly called “drone”). Hence the term resonator.
To be fair, most of the automotive industry uses these terms backwards as well, which leads to confusion.
Uhm I hate to point out the obvious but he’s showing a db graph that has virtually no resonance.
Also even more obvious the biggest contributor to an engines volume is its RPM.
Generators run at 3600 rpm to produce 60hz. Engines in general are just noisy at 3600 rpm especially ones that exhaust straight into the muffler. Strapping on an oversized muffler or resonator (even though there is no resonance) will reduce the volume from loud to still loud.
Go out and rev your cars engine to 3600 rpm and you’ll find it’s relatively noisy. And that’s with an engineered exhaust manifold, possibly a resonator, at least 1 catalytic converter, multiple feet of exhaust piping, and a muffler engineered to reduce that specific engines noise.
From some of my experimenting with portable generators. I found a great deal of noise came from the induction side. That mechanical sound of the valve opening and slamming shut makes a hell of a racket.
if you want to make it quiet you need to encapsulate the entire engine in an acoustically engineered enclosure with inlets for air and outlets for the exhaust. all the noise the motor makes is not coming just out of the exhaust port.
Attach a oxygen bottle to it then launch it into space.
Suuuuper Quiet !
@@900stx7 sarcasm 100
The majority is coming from the exhaust. That car muffler was way too big. If sized correctly it could’ve worked a lot better.
@@jeffclark5024 yeah excactly and if its still not quite enough then the next step is what i said
correct. vibration at 3600 rpm, causes residual noise/ which is vibrating air pressure...
Most of the noise from that engine is mechanical noise as opposed to combustion noise. Best way to mitigate sound from those types of generators is to incorporate some type of structure around them to deflect the sound. There are a few vids I've watched on CZcams that have worked when I tested on my units.
Be careful though, the exhaust is hot enough to start a fire. I had mine on in the winter while clearing out my storage, had pieces of wood a few feet away blocking the noise, about 30 min later the wood was up in flames and was inches away from starting my van on fire too. Gotta make sure there’s plenty ventilation, space, and fireproof material
Also The car muffler does nothing for intake noise.... Kind of a huge deal
I was thinking the same thing. It's why the more expensive Honda motors cost so much, they build them to be quiet.
Run generator in an Anechoic chamber.
But if you surround it with something that holds the heat in the generator
That's Brilliant, a rubber mount engine and the muffler is welded to the frame, fantastic.
I built a generator box out of MDF and sound proof panels and used dryer ducting for exhaust ventilation an cooling fans for air flow. Did this so I could weld in my garage without bothering the neighbors (lived in an apartment). It worked very well! Asked them in the morning after welding for 2 hours if they heard anything and they said no. From outside the garage it sounded like a truck idling volume
Go easy please, ladies and gentlemen . I know this guy. He's really a superhero and very helpful in our small town. We all love you brodyOskeez!
This guy is a hero in your town? I feel very sorry for your town
Without watching the video I can tell you you’ll learn not all the noise comes from the exhaust
Intake. Exactly. Plus an engines normally under the hood with a bunch of padding, especially with luxury cars.
Spark Jumper its a fun bid
I have a buddy whos been living off generators since 2009. He uses sheets of tin and surrounds the generator leaving the top wide open. Tin is 3 feet away and on the inside he has bed foam glued to it.Basically a dog pen with foam.
After the blackout of 2003, I researched heavily on generators, and bought the same model Birggs, but as the Craftsman branded. Waited for a Sears Super-Sale, Craftsman Club (for those who remember this) and got a super price on the Craftsman 5600W (identical to your unit, but with the bigger muffler like you showed on that 2nd unit). Beautiful unit that I bought. I babied it, did a break-in, oil change, the works. Then we never lost power until Irene in 2011. I wired to my entire house and had no power for 2 weeks! This gen ran my entire house perfectly! But it PLOWED through gas and was insanely LOUD.
As many have commented, most of the noise is mechanical.
Figuring that 2 weeks without power was not going to happen again for another 15+ years, I changed the oil, drained the gas and put this back to bed.
The Sandy hit and I lost power again for another 15 days....
While my neighbors sent extension cords under the fence on either side, they sure didn't complain about the noise, but it was horrible. And again, I was plowing through gas, when gas was hard to come by.
I just sold the Craftsman for $250 ( I think I paid like $750 back in 2003) and upgraded to an inverter gen and love it. (I have several)
I always wondered about and real sound data on adding another muffler. Thanks for doing this video! 5-6 Db is a big reduction, but as you said, this thing is still really loud! Mine wasn't much different, even with the bigger OEM muffler....
How many hours a day did you run it?
@@percyfaith11 It's usually near continuous operation when you're dealing with a post-storm power outage. People cope by doing exactly that. They might let the generator rest for an hour or so after having refueled it- but generally speaking... it's expected to run constantly. Especially when it's powering an air conditioner that's making a woman comfortable. They WON'T put up with lack of A/C if it's available. They like to talk trash about how tough they are, and how they can take it- but it's an act.
@@melissachartres3219 Not mine. She's tougher stuff and is always cold anyway. I've got a basement that's always around 60 degrees. I'm more worried about the winter. I run mine for about 30 minutes, off for 2 hours. Just enough to heat up the house, run the well pump and freezers, then off. Fortunately I've never been without power for more than 2-3 days. 2 weeks would be different.
The best way to quiet a generator is to put walls around it preferably lined with soft material.
There is a lead lined foam made for sound proofing. I used to run a 3phase generator for the movie business. We had built a hood that went over the gen exhaust and it was very quiet
I feel like this wasn't a fair test. The system had multiple holes in it, so it was going to be loud no matter what.
not to mention the baffle is probably fukced, and the guy is holding a solid object against vibrating wood
But even so, it was still about 5 dB lower, which is pretty significant. I came here expecting him to conclude that the muffler doesn't really help, and now I realize that it does make a pretty big difference. If he put a big air filter (like a car air filter) on the intake to dampen intake noise, mounted the engine and muffler with rubber mounts to reduce vibration rattle, and built an enclosure with fireproof sound dampening padding (and of course plenty of ventilation, maybe even a radiator fan hooked up to the 12v output, so that the main breaker wouldn't shut it off.. depending on the design I guess) to dampen the noise coming directly off the engine surfaces, I bet you would REALLY see a difference. I.e., basically put this into one of those whole home generator boxes. Ventilation would be the biggest concern in that case, since these air cooled engines are meant to be in open air, so you would almost definitely need to provide a straight path out of the enclosure for the engine + alternator head intake, OR use a separate fan to move plenty of air through the enclosure. This makes me want to try and quiet down an open frame generator I recently picked up, trying some of what I just thought about here. Very interesting video.
Another issue too is that the stock muffler exhaust was pointing directly at the dB meter whereas the auto muffler exhaust was pointing at the ground. That alone could account for the 5dB difference However, with that said most of the noise from an open frame genset is mechanical noise. Quiet genders are fully enclosed and lined with sound absorbent materials and the airflow passes through baffles to help contain the noise.
He also held the Meter further away on the second test . . .
⚠️Always make sure you follow all the generator safety rules when you use your portable generator:
This is just a reminder to make sure. It is important to follow all generator safety rules whenever you use your portable generator.
Here are the things that need to be followed;
1) KEEPING OTHERS SAFE: Please do not allow an unqualified person or your children to operate and service the portable generator. Just because some manuals don’t say that doesn’t mean it’s safe. That is important against the generator safety rules. We also need to be keeping an eye on our children too. You need to make sure that your children are not playing near the portable generator especially when it’s running so they won’t get electrocuted. Generators pose electrical risks and they can be hot during an operation. Please keep your children away from the portable generator at all times. It is important to keep our children safe especially our little ones. Be aware of all the hazards.
2) WHERE TO RUN YOUR GENERATOR: Some people use their portable generators indoors which increases the risk of carbon monoxide poisoning. It’s important to have a carbon monoxide if you have a gas generator. Never ever use your generator indoors even if your doors and windows are open and even in the garage is not safe to use a portable generator. Not even at your porch and your deck. It is never safe to use your generator indoors and in enclosed areas of your home. Your generator needs to be 15-20 feet away from your house.
3)🔥FIRE HAZARDS: Never refuel your generator while it’s running. You need to let your generator cool off before refueling it and before storing your generator. Never overload your generator too. Never ever back feed your generator. You should never plug your generator into a wall outlet. Also never store propane tanks indoors. Please keep flammable things away from the generator as well and please don’t smoke cigarettes near the generator. Having a fire extinguisher next to the generator is also important against the generator safety rules.
4) GENERATOR OPERATION: make sure your hands are dry before touching the generator. Never use your generator in wet conditions. Don’t let your generator get wet. You need a generator tent if you need to use your generator during wet weather. Please don’t wear loose clothes when operating the generator. Turn on your generator before plugging in appliances. Use the right cord for your generator. Please do not use worn out cords.
czcams.com/video/I1jT3ANENvI/video.html and here is a video more about keeping others safe when using generators
Hope this helps
5 Decibels quieter is HUGE in terms of sounds, so it worked VERY well.
Love that Most of the video is excessive repair after removing the muffler. But when you did the initial test you used a chunk of wood to block the massive hole.
Solid mounting a muffler to the frame, and having the generator on rubber mounts is just begging to bust something
Needs a bit of flexible exhaust...you are correct👍
Don’t be so dramatic...
Thats exactly what i was going to say! Thats why the one bolt was loose. Probably had a blown gasket behind where it bolts on too.
Great for testing though.
Yes, mountbthe muffler to the motor or flex hose and rubber hangar
dB's are normally taken at a 3 meter distance. dB reader app isn't a highly scientific method. Hole in muffler, fix it first, source of error.
dB apps - ding ding ding! You are correct. I have tried six different apps for dB registry, and have a range of 20 dB between them - same weightings. My church has a ham-fisted sound board operator who thinks he is mixing Cheap Trick at Budokan (yes, I am THAT old). I started taking readings so I could speak intelligently with the people in charge. I wound up getting my hands on a calibrated and certified stand-alone unit (BK Precision) and ran it side by side, and narrowed it down to two apps that were fairly accurate across background and transients. When I was still doing sound work 25 years ago, we would take readings at 1m, on axis from the source. There were strict local ordinances about sound pressure at live events, with live or recorded music. (the kind of ordinances that held the sound company responsible for infractions and subsequent fines). With the genset quandary, it also helps if exhaust is pointed away from mic. Car muff pointed down, Briggs & Stratton muff pointed at the mic.
Isn’t highly valid*
B.A. Gage you went through all that, mention 2 apps that were fairly accurate. Which apps?
I always cringe when people say they are going to do a "sound test" and then bring out and app on their phone. Get and actual device that was designed to do that
@@scvic2006 need to look, have not used since March (no church since then).
I have used an old satellite dish in the past at campsite to deflect sound into the woods. I put it between the generator and campsite aimed outwards. The parabolic shape seems to narrow the "beam" of noise making it easy to aim.
I was thinking the same 2 days ago while working on my generator, no google searches, no speaking in to the phone, no discussion with anyone... and youtube shows me this video..... scary times we're living in.
So, if you put the generator inside a car, and route the exhaust through the car's muffler, you should be golden.
There are RVS that have the generator at the other end of the vehicle, on their own exhaust.
Those seem to run exceedingly quiet.
They are also in their own bay, and a lot of them are water cooled, so heat is not so much of an issue.
Garage 54 filled an entire engine bay with expanding foam, and the engine was, obviously, super quiet.
Before you ask, yes, it caught on fire.
It's good to know that there are people that will do apparently stupid things for us, so we can learn without endangering ourselves.
That is not to mention trying an expensive experiment that will cost an individual a lot of hard-earned money to see if something works!
Not exactly. The car exhaust is likely higher pressure than the generator's exhaust, so the car exhaust would try to push up into the generator. That would make the generator work harder and likely cause it to malfunction.
@@SomeGuy-vo7we I'm pretty sure the joke/point I was trying to make was that the original idea was to make the engine quiet, like a car, and so the solution is to take all of the efforts that combine to make a car quiet, and employ them on the "good start" that was attempted, but with a dual-meaning of wasting a car to use as a "doghouse", to keep the noise of a small generator inside (absurdity humor). I'm glad it got your ideas going though. :)
@@danieljones317 I saw that G54 video. Those fellas have some great content! I think a lot of it is the benefit of having so many simple, inexpensive cars wherever they are... I'm certainly envious of that, as the USA is laid out for a constant need of automobiles, yet the complexity/prices/maintenance are prohibitively high.
More testing required, the "Combo" muffler was flawed, in that there was a sizable leak, that was never repaired. my hypothesis, is the hole was not adequately sealed just by pressing a random hunk of wood against it.
In a part two, perhaps re attach the car muffler directly, and port the exhaust away from the staetor, potentially also repair the old OEM muffeler and retest. hmmm...
The SixtyFiveFord channel found DRAMATIC sound reduction (not just in logarithmic decibels, which is so-so at low levels, but sound-on-eardrum noise) by simply placing plywood around the running unit. If the plywood were secured and sealed, you'd see incredible results. The answer is to give the unit a well designed enclosure instead of a well designed muffler (or both) and that'll make all the difference.
One of the things I used to do is to build a small shed out of foam with ventilation at the top to put my generator in. I made it out of half inch foam and it helped a lot. I just cut the pieces and taped them together. You just have to make sure it is big enough so the generator is not too close to the foam. For the vents I just made the roof of the shed like a gable end roof on a house and at the peak I cot openings to let fumes out but keep the rain from getting in.
Having worked in the petro driven welder/generator industry a baffled and insulated box with cooling air flow and all the noise directed upwards works great! The best i have seen are MQ generators
Mity Quip
I learned long ago, on fully built out 2 strokes, that the carburetor emits an incredible amount of noise! Maybe putting a resonator box and long intake tube would shut the generator up a bit more?
very interesting idea
We should demand a whole series on quieting this generator
How does Onan by all accounts the quietest generator do it?
Maybe getting rid of the hole and then doing some sensible experimentation which would include measuring electrical power output would be the way forward!
Too bad the engine in this case isn't a 2 stroke.
I love the transtion of the attitude:
4:53 - I will be nice and gentle
5:03 - oh crap
5:34 - screw it, lets just get it done
6:25 - BTW, nice finnish! no damage to the frame.
Thanks
Interesting stuff! What’s important to note is that 6db is actually 4x as loud so the muffler was working pretty well I’d say. Most of the noise that remained was probably just from the mechanical parts of the motor.
Intake noise as well.
True, but was just trying to say that people should not have unrealistic expectations. It was still loud.
@@jcondon1 Yep, even sheet of plywood can make a big difference if the right surroundings are available.
@@jcondon1 Wonder how much noise came from the loose bolt. 🔩 Even slightly loose, it can cause a lot of sound.
I used to have a boat fitted with a single cylinder 6hp petter diesel. The exhaust pipe was plastic and water injected, with fitted an anti siphon valve to prevent water being drawn back into the engine. That was quiet. Might be an interesting project to test.
Wow this was a pointless and uninformative test. Doing a noise test with a hole in the muffler? Loose bolts? And on top of all that, you've managed to make it louder.
Right? Like what the literal fuck!? I quit as soon as I seen that..what has this world come to when this shit show is made, like the time he took out of his life to make this, and not for comedic enjoyment no no for serious consideration on whether or not to put a muffler on your generator...
Lmaooo funny af the way you put it
@@jessejames3600 its not that deep oh my god lmao
@@Nyancide no it's not!
Ikr. I clicked thinking "ooh interesting idea". Then says " oh yeah, there is hole in mufflers but I'll block it of with this random piece of wood", and I'm like bruh...
a 2 min video squeezed into a 10 min video.
Kidding. Loved it.
Well a few things I took notice of, for one a full automotive system would include a resonator to highly improve the capability of the muffler(catalytic converter helps greatly not needed). To reduce noise further the exhaust tip should never be pointed towards the ground always Parallel or greater for best results. Installing supports with accompanying bushings can reduce mechanical noise caused by vibrations. Lastly the hardest to install in my opinion is ideal sized piping, sometimes the best pipe size is OEM do your research and do not expand pipe size beyond system capability.
This was a fail test willing to cut the muffler off but not willing to adjust the muffler to work
⚠️Always make sure you follow all the generator safety rules when you use your portable generator:
This is just a reminder to make sure. It is important to follow all generator safety rules whenever you use your portable generator.
Here are the things that need to be followed;
1) KEEPING OTHERS SAFE: Please do not allow an unqualified person or your children to operate and service the portable generator. Just because some manuals don’t say that doesn’t mean it’s safe. That is important against the generator safety rules. We also need to be keeping an eye on our children too. You need to make sure that your children are not playing near the portable generator especially when it’s running so they won’t get electrocuted. Generators pose electrical risks and they can be hot during an operation. Please keep your children away from the portable generator at all times. It is important to keep our children safe especially our little ones. Be aware of all the hazards.
2) WHERE TO RUN YOUR GENERATOR: Some people use their portable generators indoors which increases the risk of carbon monoxide poisoning. It’s important to have a carbon monoxide if you have a gas generator. Never ever use your generator indoors even if your doors and windows are open and even in the garage is not safe to use a portable generator. Not even at your porch and your deck. It is never safe to use your generator indoors and in enclosed areas of your home. Your generator needs to be 15-20 feet away from your house.
3)🔥FIRE HAZARDS: Never refuel your generator while it’s running. You need to let your generator cool off before refueling it and before storing your generator. Never overload your generator too. Never ever back feed your generator. You should never plug your generator into a wall outlet. Also never store propane tanks indoors. Please keep flammable things away from the generator as well and please don’t smoke cigarettes near the generator. Having a fire extinguisher next to the generator is also important against the generator safety rules.
4) GENERATOR OPERATION: make sure your hands are dry before touching the generator. Never use your generator in wet conditions. Don’t let your generator get wet. You need a generator tent if you need to use your generator during wet weather. Please don’t wear loose clothes when operating the generator. Turn on your generator before plugging in appliances. Use the right cord for your generator. Please do not use worn out cords.
czcams.com/video/I1jT3ANENvI/video.html and here is a video more about keeping others safe when using generators
Hope this helps
Decibels isn't a linear scale, so the car muffler (even with the hole covered with wood) was much quieter. Try a car muffler with no holes.
Muffler or silencer is not made to quiet a Car or generator.The purpose of a muffler is to assist catalytic converter which operates at 1000 celcius to prevent back pressure of gases to engine. Car engines idles at 900 rpm and a 4 pole generator (diesel) operates at 1800rpm which is fairly less noisy. More the rpm more noisy it gets. Feel free to ask more.
@@iamarxalan mufflers are 100% designed to quiet the noise from the exhaust. Don't know where you got any other idea from. And from firsthand experience going from a muffler with multiple large holes in it to a new one with no holes, it works too.
@@ethanlegler6403 do you own a car?? I am sure all cars have pre-installed mufflers.do one thing open the front hood. Ask some friend of yours to put car in neutral and accelerate (reving) it, watch rpm meter of your car on somewhere between 3 and 4.(3000 rpm - 4000rpm) record the sound using same decible meter and then tell me. Prove me wrong if you can.
@@ethanlegler6403 catyltic converter releases carbon dioxide and nitrogen gas at 1000 celcius which can easily burst aluminium pipe of exhaust if you remove a car muffler.This muffler /silencer allows to expand inside it's space preventing further damage.
@@iamarxalan the sound from the engine bay? Or course, that'll be loud still. The muffler is designed to quiet the sound from the exhaust, not the engine in the engine bay. Have you ever heard a straight popped car vs a stock one? The straight-piped one is always going to me louder because it doesn't have a muffler to, oh I don't know, muffle the sound? It's in the name ffs. It's there to muffler the sound!
I have a plain square wave gas generator. It's loud! I bought a Champion inverter dual fuel gas/ propane generator. DB's run in the 50's. Good clean pure sine wave power and quiet. Starts real easy on propane. Now I have a quality quiet generator to run circuits in my house and the electronics in home appliances won't be destroyed by a dirty square sine wave. I have the best of all worlds!! Problems solved!
Those welds are absolutely beautiful
We're going to test this noise, btw, there's a large hole in the exhaust!!!
Engine is loud, not the muffler. You are hearing engine racket.
This... a large proportion of noise from cheap "contractor" generators is directly from the motor itself, not the exhaust. That's why the backup generators designed for houses are in insulated boxes/covers in addition to having a better muffler.
@@infurious5748 it would also help to have a better engine, say a Honda OHC and then build an enclosure around the entire assembly making sure to allow for plenty of air flow for cooling.
@@brianbumgardner8704 Or just buy a predator 3500 from Harbor Freight for $800 that is only 57db
Yeah. Those B&S engines are noisy. I did a little test years ago. Cupped a car muffler over the exhaust pipe of a B&S engine on a riding lawnmower. Made VERY LITTLE difference. I mean, it had a smoother less harsh exhaust sound..but all that engine racket was still there. Hondas make much quieter engines... but you'll pay for it.
I was writing a detailed comment, but I gave up after a few paragraphs.
Conclusion: bad test, bad testing methods, but even this was enough to prove a good concept. Generators can be very silent for some extra cost.
👍Some people put them in a below ground pit enclosure, makes a big difference in detectable noise.
It woulda been a bigger difference without the blown out stock muffler. Several years back my buddy and I were building dirt drag trucks my old boss let us use a small shop on the truck yard he wasn't using also loaned us a gas power air compressor to use. Well inside that shop that gas air compressor was loud as hell on us so we took the factory muffler off my buddy's chevy luv truck and our 110 welder we welded a pipe on the compressor engine and ran it outside the shop then welded the factory pickup muffler to the pipe. Wala all you could hear was the actual compressor pumping air just like you would on a electric compressor and outside the shop you could barley hear the engine noise coming out of the muffler. So I think the blown out generator engine muffler was why it was so loud with the car muffler I bet when who ever first did that it was worth the effort.
I don’t think he stopped the original muffler up though. Gas travels to an area with least resistance, so what needed to be done was seal the original muffler up which wasn’t what he did (or at least I’m pretty sure he didn’t seal it up) if he had done what you did though, it would’ve been worth the time
Most of the noise is actually coming from the engine block and the valve cover. The exhaust is inconsequential.
Small engines like this aren't really something you can quiet down with muffler. Thats why people came up with generator quiet boxes which work well
I have a Champion 3,400 inverter generator. The side panel comes off to change the oil. Without that cover the engine is much much louder. Keeping the cover on makes all the difference. Good video! Well done! Keep in mind the decibel level is not linear, it's exponential.
I found the same with the Honda EU 2000i. Take the simple plastic side cover off and the unit is noticeably louder.
I bought a big cheap welcome mat that I lay over it for weather protection. Sometimes add a small piece of plywood if it’s snowing or raining sideways. That’s enough to knock off a few decibels.
Spolier: 5 dB difference
Every 3 dB is twice the noise level, so 5 dB is significant.
1:58 & 9:30
It would also be interesting, if the comparison could have also been done with the engine loaded: Driving a couple of space heaters, to put a substantial load on the engine. You're right though, open frame generators are inherently loud. The best muffler in the world won't silence one of these. The biggest concern I have, is with vibration. When I've tried something like this, the vibration from the engine broke the weld between the exhaust flange and the header pipe, because of the cyclic stress from vibration from the single cylinder engine. I got the same result. It just didn't make it enough quieter, to be worth the trouble.
The weld you mention broke because you didnt mount the muffler on rubber bushes, like the engine is. DOH!
my boxed in and somewhat noise insulated permanent install generator is loud. sounds like someone is running a diesel outside the house, but it is just a 2 cylinder air cooled generac
@@roberttill3787 You're right, but, it's a little more involved than that. A cyclic motion on one end of the muffler causes it to want to rotate around it's own center of mass. therefore, there will always be a cyclic cantilever stress at the exhaust flange. The thing to do, is to use a ridgid mount between the center of mass of the muffler, and the center of mass of the engine/generator assembly. That way, it all moves relative to itself, avoiding any cyclic stress. The trick is, to create a mutual center of mass between the two masses. (muffler, genset) The only other option, is to use some kind of a flexible coupling, that will remain within its elastic limit, with the excursion of the vibration. (a method used in some auto exhaust systems) The only problem with flexible couplers, is it allows noise!
⚠️Always make sure you follow all the generator safety rules when you use your portable generator:
This is just a reminder to make sure. It is important to follow all generator safety rules whenever you use your portable generator.
Here are the things that need to be followed;
1) KEEPING OTHERS SAFE: Please do not allow an unqualified person or your children to operate and service the portable generator. Just because some manuals don’t say that doesn’t mean it’s safe. That is important against the generator safety rules. We also need to be keeping an eye on our children too. You need to make sure that your children are not playing near the portable generator especially when it’s running so they won’t get electrocuted. Generators pose electrical risks and they can be hot during an operation. Please keep your children away from the portable generator at all times. It is important to keep our children safe especially our little ones. Be aware of all the hazards.
2) WHERE TO RUN YOUR GENERATOR: Some people use their portable generators indoors which increases the risk of carbon monoxide poisoning. It’s important to have a carbon monoxide if you have a gas generator. Never ever use your generator indoors even if your doors and windows are open and even in the garage is not safe to use a portable generator. Not even at your porch and your deck. It is never safe to use your generator indoors and in enclosed areas of your home. Your generator needs to be 15-20 feet away from your house.
3)🔥FIRE HAZARDS: Never refuel your generator while it’s running. You need to let your generator cool off before refueling it and before storing your generator. Never overload your generator too. Never ever back feed your generator. You should never plug your generator into a wall outlet. Also never store propane tanks indoors. Please keep flammable things away from the generator as well and please don’t smoke cigarettes near the generator. Having a fire extinguisher next to the generator is also important against the generator safety rules.
4) GENERATOR OPERATION: make sure your hands are dry before touching the generator. Never use your generator in wet conditions. Don’t let your generator get wet. You need a generator tent if you need to use your generator during wet weather. Please don’t wear loose clothes when operating the generator. Turn on your generator before plugging in appliances. Use the right cord for your generator. Please do not use worn out cords.
czcams.com/video/I1jT3ANENvI/video.html and here is a video more about keeping others safe when using generators
Hope this helps
That's exactly right. A mounting placed right at the center of mass of the muffler, rigidly coupled to the center of mass of the main gen set, will help stop all relative motion between the two components. Another problem, is that the reciprocating piston is at one end, while the alternator rotor is at the other. The engine end vibrates out of phase with the alternator end, so there is also a rocking vibration, as well as the radial vibration, as it rocks on the center of gravity. The whole thing is suspended on rubber motor mounts, which allows that vibration.
In terms of sound pressure levels. 75DB is At least twice the sound pressure of 70. It is a logarithmic scale. If the automotive muffler was installed more professionally and it didn’t have a big leak that defeated it’s purpose ( like you tested it) the measurements would have been much more impressive. Still an impressive video. Thanks.
It's been my experience that an additional muffler really makes no remarkable difference,
since even the quietest of the quiet-gens are anything but quiet.
So,
for anybody who considers the noise too much of an annoyance, my only solution has been to move the noise to where it isn't as annoying by building a large enough insulated dog house outside with removable panels on all sides for starting, maintenance and removal for portability.
The panels should have register vents on all four sides to allow cooling air to be drawn in that are available at hardware retailers.
And,
I found that the most effective roof is a pyramid type with a stack at the top for the heat & exhaust to flow out.
The stack can be made with a piece of 4-6" aluminum dryer duct conical topped like a toilet gas roof-vent pipe & screened to keep rain & birds out.
And,
UF type romex wire can be burred between the gen-shed & a convenience outlet either at or in the house.
Or,
no more often than an emergency gen needs to be used anyway you can always just use a good heavy-duty exterior grade extension cord.
Of course it would cost a pocket of change to get a handyman to do it.
But if you happen to be a DIYer it takes about a weekend.
And weather or not it's worth it really just depends on perspective.
Personally,
I've been living Expat fashion in the Philippines for ten years where the local infrastructure leaves enough to be desired to make brownouts & periodic blackouts a pretty common fact of life and necessity no-less typically becomes the mother of invention.
Every three db increase constitutes a doubling of the sound signal. Also, as others have mentioned, mechanical noise is a huge component of the noise these small engines produce. Interesting experiment.
10db
put the pipe in a bucket of water. thats how boats do it
Jimmy Landers innovation
Did that with my 18hp Honda V Twin pressure washer. Did work but kept blowing the water out of the bucket. It was a beast at 3,000 rpm.
Never thought of that. I used to have some problems when running my Mortar Mixer in Residential area's. Retired now no problem.
@@dljones61 bigger bucket
Lol
Quiet generators are always multi-cylinder engines. Except for those new-fangled inverter generators. Those are just magic.
To make a generator near silent, we always build a pipe to slide over the final exhaust pipe & point into the ground. Of course, we did a straight-down hole with post hole diggers, then place the generator over the hole with the pipe in the ground. RV folks, campers, etc have been doing this for decades
Most of the noise you hear is mechanical engine noise.
Exactly
Air cooled engine is louder.
This comment is the only comment that matters.
Yep
Can confirm. I found a small tractor muffler to put on mine and while it did quiet the combustion noise, the mechanical noise from the moving internals was still loud. I built sides and lined it with mineral wool insulation Batts and that is what truly quieted the generator down.
Each 3db is a doubling of intensity. To the 6db increase is four times louder. +/-6db is considered a "significant change".
Interesting video. As many people stated, the right muffler matters but also key is a small as possible ending exhaust pipe. Just ensure it’s not too small that it restricts the exhaust gas too much.
during an eight day power outage I put an old motorcycle muffler on my generator. it did the trick. most 2 stroke motors I've seen have 1" npt threads in the exhaust port making it super easy modify the exhaust.
I always chuckle when someone pulls out a Dremel.
They are often disppointed 😃😃
I've used a Dremel to cut bolts or grind in really tight spots. You can't put a lot of pressure on them, but they'll get to places not much else will. The use of the Dremel in this video was unnecessary, which was proven when something more appropriate was used to actually finish the job.
I rarely use those cutoff discs anymore, they’re just too damn brittle. I much prefer the ‘speedclic’ ones. They’re thicker and perhaps not suitable for all jobs, but at least they don’t explode sending pieces of abrasive disc all over the workshop, in your face, etc.
That was a heavy duty weld. I knew that little dremel cutoff wheel was going to crater in a heartbeat. You’d be lucky to cut thru a single 1/4” bolt with that disc. Grinder with cut off wheel was the appropriate tool for the job.
It definitely helps if you know how to use them properly.
Leave the dremel in the wife's hobby room. You want a cutoff tool get one.
I was planning on basically putting a dog house without a roof, around it. To deflect sound upward like they do next to the freeways. I think that would help
Yes great idea, and leave the dog howling .. great distraction.
Air cooled generators make a lot of higher frequency noise from the flywheel blower. The exhaust muffler is strong in lower frequency noise. Higher frequency noise is more annoying to most people. The exhaust noise gets greater as gen loading increases.
I have a 15kW 'portable' Generac generator with 990 cc twin V engine. From flywheel end of generator it sounded like a jet engine and is louder at seven yards away compared to facing muffler outlet side of generator. I made a large acoustical isolation baffle screwed to frame with half inch foam gasket from baffle box pressuring around flywheel air intake. Baffle was designed not to restrict air intake flow. It helped to greatly reduce the high frequency noise.
Lemme save you the watch, We tried this with a buddy of ours' loud ass obnoxious generator that he takes to the racetrack with us when we go out of town. NOTHING can make that clanky uninsulated pile of decibels quiet! We exile him to the far pits when he camps because that thing keeps everyone awake. It sounds like a toolbox filled with tools falling down flight after flight of stairs! The engine sounds mostly are from the internals and not the exhaust. If you want a quiet generator you'll have to buy one that's already engineered to be quiet, or burn your race camp / campsite / home to the ground trying to cobble together some insulated enclosure that don't end up overheating the engine and generator, subsequently starting a fire! We run an Onan quiet diesel in our camp and you can sleep next to it. Cheers
Interesting video. I worked in a muffler plant for 13 years and muffler back-pressure on the engine is very important to longevity. Not sure how that would apply to small engines only used for short periods of time. Personally I'll just stay with the sound enclosure approach.
a generator though is used for several hours at a time during a major event. Hurricane Isabel hit here in 2003 and some homes didn't have power for an entire week. Small-engine manufacturers recommend changing oil ever 50 hours of use....that was almost every two days!
Nope
I’m afraid the experiment is still flawed because the loose screw on the muffler on the original setup also indicates you had a blown gasket in the exhaust manifold as well. I assume you changed it with the new muffler. I would have loved to have seen a good gasket on the old system for manifold as well as a repair sealing that rusted out stock muffler/welding etc.
Don't mind the hole in the original muffler..
both tests had the same "blown head gasket.
He doesn’t generally change the gaskets.
I kinda figured the test wasn't to be taken too seriously when he blocked a exhaust leak with a piece of wood
3db difference is a doubling of sound energy. A car muffler does maybe half of the work of sound dampening (the complete muffler has sometimes 2 or 3 chambers along the line) BUT THE REST is done by the engine cover, the hood, and the bodywork of the car. A generator can be encased, with input and outputs for cooling and breathing. Then the muffler will help to complete the sound dampening. The engine mounts are also rubber parts to dampen vibration, and that is also huge in a car to make it liveable. (you don't need any in an electric car)
Lighten up guys. He did point out the hole in the exhaust. He also pointed out that he received the genny as such
The first problem with this is that the exhaust bolt was loose, it's truly surprising how much noise an exhaust can make at the exhaust flange through a loose gasket interface. MUCH more than you'll ever get out of that hole on the outlet side. Second, since you don't need nearly what that muffler could flow there's a big gain to be had by necking down the exhaust pipe coming out of the muffler.
Finally, I'd bet the majority of the noise you're getting is actually mechanical noise from the engine and generator. That would be interesting to test to try to figure out what is coming out of the exhaust, what is coming out of the intake, and what is mechanical noise.
I’m glad you did this, because I have that exact generator (but with the other muffler) and I’ve thought about doing something like that. 6dB is significant but not significant enough to go to the trouble. Thanks!
Unusual rehearsals are beautiful. Well done!
6 decibels. 👍 technically it’s a 4th factor quieter. The neighbors would definitely notice. 😅
One of the issues with Briggs & Stratton engines is the DB level comes more from the drivetrain noise than the exhaust. Some exhaust is better than others though (I once put small diameter glass packs on a riding lawnmower - cool sound but not much louder, merely a different tone of loud).
FYI, 'glass packs' and other straight-thru 'mufflers' are relatively bad at sound reduction because they prioritize unrestricted flow. They aren't even in the same tech/design ballpark as 'tuned' mufflers found on factory cars and such that are willing to impart some (often negligible) degree of restriction for greatly improved (perceived) sound reduction. The effective kind of muffler has chambers and baffles to break up and change the exhaust flow/sound, while glass packs and almost all small engine 'mufflers' barely reduce loudness by being a small expansion chamber with or without sound-deadening materials like Fiberglass packing.
All that to say, there's a huge difference between a perforated tube muffler like a glasspack and a tuned, chambered muffler that fundamentally changes the exhaust pulses into something far quieter. This is such a big misconception that it's kind of crazy that the terms lead people to not know the difference.
My generator's muffler is probably half the size of that car one that was on there. Works well. Can have a conversation beside it
Huge diesel generators I worked on in the Navy were inside a sound insulating module, like a room in a room. Building a small insulated box around the generator would help. Tall like a chimney and open on top.
I did this to a generator with a 10 HP Tecumseh engine one time. Those things were nothing but a bucket of bolts that made too much noise and had mufflers the size of a fist. There’s nothing you could do to quiet them down, although they would run. I have a Generac now with the same motor as this one that you have, and is basically the same generator. Mine has the larger Briggs & Stratton muffler on it and it is quiet enough.
Having the muffler welded directly to the frame is wrong, it will shake something loose, as the motor is free to shake, but the muffler is not. Muffler should be "suspended' from the frame.
Znobyrd That could explain the hole in the exhaust if you think about it. The vibration has to be absorbed somewhere.
Plus that could add vibration noise as well through the frame.
Best thing to do to quieting one down is to build a insulated box for it. It really doesn't make it quieter, but you can direct the sound.
Hey James, my neighbor recently asked me if I could put a muffler on his generator to make it quiet like those small Honda’s. I said anything could be done but it won’t make much difference. Thanks to your video, you proved it!
Thanks Henry. If you want quiet, then an inverter generator is the way to go. The car muffler did very little.
My technique is to start the Gen set, plug it in, turn in the breaker then throw the Gen set in the nearest lake, perfectly quiet, just amazing result.
Was the muffler pointed straight down to make it louder *_AND_* set fires?
Pointing it at the ground would make it louder as the exhaust is bouncing off the ground.
covering the hole in the exhaust with a piece of wood was a nice touch though...
A muffler kinda acts as a spark arrestor. I've owned a good amount of ATVs and alot of them are designed with the pipe downward. Abit higher off the ground but still. Further, if a motor is spitting sparks or unburned fuel its probably way out of tune or ready to croak
I'm certain that's not right, the rotary engine guys sometimes have the tip pointed straight down to help pass the DB test to get on track.
Honestly thats a good amount of change. A lot of the low end frequency has been reduced with the muffler. Low end frequencies also travel the furthest. This is honestly such a good idea. I wonder what will happen if you put a catalytic converter on too. Thanks for the video that i never thought I needed to see.
I did the exact same thing...went to auto parts store and asked for the smallest car muffler they could find. I think it was for a geo metro or ford festiva or something like that. it reduced the worst of the noise...took the edge off but not as much as I'd hoped. It was for running bouncy castles so the less background noise the better. was worth it in my case.
Get a honda generator. You can barely hear them at 20 feet.
26 branding disks later , I thought was gonna be MY title for this video .
Thanks . Good work
It's an air cooled engine, they are prone to being loud regardless to how large the muffler is. To quiet the generator, you have to put it into an enclosure with heat resistant sound deadening insulation.