Silent lawnmower muffler?

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Sometime I like to mow my lawn very early in the morning...like right after the sun comes up. My neighbors don't partiularly like that.
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I was thinking today, my jeep is almost 200hp, and 242ci. With the muffler it has it's amlost silent. My lawnmoer is not quite 7hp, and about 12ci. It sounds, well, like a lawnmower.
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Why are lawnmowers so loud?? Is there an aftermarket muffler I can get to make it nearly silent?
 
Good post VaderSS. People tend to confuse noise and power. A nice quiet mower, vacuum cleaner, etc. is seen as lacking power.
 
you cant really ever quite a mower, no matter what you do to the exhaust, the blade is awalys going to be whooshing air around and making noise.
 
Well I was going to suggest electric, but since you mow your grass early in the morning you're going to need something more powerful to get through those clumps of wet grass!
 
They claim to lower the noise of a 5HP B&S to 95 dB at 20" with th 3S/resonator combo. That's the same level of noise as a subway train at 200 feet. To put it in a different perpective, you should not be exposed to a normal power mower, without ear protection, for more than 1 hour. 95 increases that to 4 hours.

It decreases it to 70 dB at 50' which is the quiter than the average car interior on the highway, as opposed to 80, which is the same as a dishwasher.

Keep in mind that dB is not a linear measure, but a logarithmic one.
 
That looks like a pretty good muffler, however, my intek doesn't have a threaded exhaust for it.
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They may make a threaded flange to bolt on. I have used a flange from the plumbing departmnent. I think I had to drill new holes in it.
 
I prefer to mow in the afternoon/evening when the grass is drier
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... but the quiteness issue remains the same.

Think Big. You'll probably need a small passenger car muffler (Suzuki Samurai, Geo Metro, Toyota Echo, etc ...) mated to the exhast port/flange. Route/sit the thing wherever there's room (up top, away from the intake and pull-start. Turn the exhaust tip downward.

But, is this really practical and cost effective? Of course not ... but this is BITOG where extremist measures are a virtue.
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--- Bror Jace
 
quote:

Originally posted by ZmOz:
Sometime I like to mow my lawn very early in the morning...like right after the sun comes up. My neighbors don't partiularly like that.
grin.gif
I was thinking today, my jeep is almost 200hp, and 242ci. With the muffler it has it's amlost silent. My lawnmoer is not quite 7hp, and about 12ci. It sounds, well, like a lawnmower.
smile.gif
Why are lawnmowers so loud?? Is there an aftermarket muffler I can get to make it nearly silent?


Consumer level lawnmowers usually run cheap exhaust systems, but you quickly realize that even on high-quality mowers, such as the Lazer-Z I mowed on last summer, that the bulk of the noise, at least on big-deck mowers, comes from the deck itself.

I'm really sensitive to loud noise, and while I can stand the noise of the engine itself (a air-cooled, OHC, V-Twin gas), the noise once you engage the deck is overwhelming, and ear protection is needed.

If you're really serious about this though, I agree with Bror that the best thing to do is to go buy an automotive muffler and weld it up. Cut the pipe coming from the engine before it gets to the factory muffler, and then run some new pipe from the old pipe to the new muffler. I don't know if you can weld or not...but just bring it by a muffler shop. They can do it for you.

Like I said, the deck itself makes a great deal of noise, but running an automotive muffler will significantly reduce engine noise, and on consumer sized decks, the noise shouldn't be too great...
 
As I think about it, the noise level does go up when you engage the blades on a mower deck. Even quieting the motor won't stop that.

The real solution to noise is electric. Too bad they never caught on. I am still running the one I bought in 1973. I must admit that is only due to extraordinary efforts on my part. It is a GE E8M. It has 3 large deep cycle batteries and a separate motor for drive and each of the 2 blades. Yes I have spent a fortune replacing batteries over the years. It is worth paying extra for things that work well. Besides, better, cheaper, rechargeable batteries have always been coming soon, even going back to the 40's. Much of the noise it makes, comes from drive line noise and the blades themselves. It is belt driven to a 3 speed transaxle. The blades are directly driven by their motors without belts and pulleys.

I think part of the problem was typical mid 70's American quality combined with the lawn mower people knowing small engines, but not electrical. Think about how much easier it is to find people to fix mechanical problems than electrical ones.
 
I've used electric mowers that have a standard lawn mower blade, and while they were still relatively noisy, due to the blade, the whooshing noise is much less grating than the "brah" noise of the gasoline engine. The "brah" also seems to carry further than the whoosh. Muffling that "brah" noise would still help a lot.

I think Blue99s idea would be the quietest though.
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Yeah, definately alot of the noise is from the engine alone. I have quite a few small engines and am working on them all the time, they are still really loud when there is nothing attached to the crankshaft.
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I happen to like the sound of the engine...I have a generator with an open header.
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I just don't like pissing the neighbors off at 5:00 in the morning...
 
One way i have seen done was to thread pipe from the exhaust going 90 degrees into a hole drilled into the deck. then a small muffler was attached to the pipe, right where the deck is. There was enough room between the muffler and the blade, but not too much. It was really quiet, but I don't know if it ever lasted or not.
 
It depends on what mood I'm in. Sometimes I like the sound of an engine, sometimes not.

Besides, I'f I'm not burning gas, checking engine oil, etc ... I don't feel I've accomplished as much in the yard. The oversized-desk-fan-on-its-face concept probably works well, but you won't see me with one anytime soon.
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Yeah, however exhaust attaches to this engine, you would have to start there and build/adapt a flange and then fabricate the steel tubing yourself to accept the muffler. I'm talking proper tube bending and careful welding. Not an easy thing to do. I know I don't have the tools.
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I'd be sure to have at least one 90 degree bend to help cancel out the noise.

Plus "Muffzilla" (even the smallest aftermarket automotive mufflers are gonna be massive) is gonna need an extra bracket or two attached to the deck to hold it in place.

Forget the long and skinny mufflers designed for ricers.
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You want something shaped like a swollen football ... fat is phat.
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--- Bror Jace
 
The blade does make alot of the noise. Also the type of deck you have will make a difference as well. Steel decks will be noisier that cast aluminum or plastic decks.
 
Good thread. I've been wanting to find a way to silence my power generator. Remember the 2003 Blackout? It came during a heatwave. And I live in suburbia. The people sleeping with their windows open and the LOUD generators grinding away through the night didn't make for a good mix. (Just so you don't jump to conclusions, I lent my generator to the neighbor across the street for that night).

Would a small automobile muffler cobbled to the exhaust port silence my generator enough so the neighbors and myself can have peace during the next outage?
 
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