Why are outdoor power equipment engines so loud?

[The motor guy]

I'm talking about why don't they put better mufflers on these things to make them quieter? Now. Let's forget for a minute that usually whatever that engine is turning is usually louder than the engine itself. Mower blades, blower fan blade etc. I'm just talking about the engine itself.

 

[walterjay]

$$$

 

[Ausfahrt]

Because they are mostly air cooled and don't have coolant jackets to insulate the noise.

 

[The motor guy]

Because they are mostly air cooled and don't have coolant jackets to insulate the noise.

I always thought that if they put an overly restrictive muffler on, it will cause it to overheat

 

[Ausfahrt]

I always thought that if they put an overly restrictive muffler on, it will cause it to overheat

You're missing the point. Water cooled engines are quieter because they have water passages instead of fins on the head(s) and the water (coolant) dissipates heat and also sound.

 

[ripcord]

In general, small gas engines have less mass and thin walls, so even if you put a big and super efficient muffler on in them, they're still pretty loud.

 

[The motor guy]

You're missing the point. Water cooled engines are quieter because they have water passages instead of fins on the head(s) and the water (coolant) dissipates heat and also sound.

No, it makes sense

 

[danez_yoda]

I saw a generator silencing video that a person tried to put a car muffler on a generator to quiet it down. Barely moved the needle. The noise came from the engine and the carburetor.

 

[4WD]

If you are talking lawn tractors - I don’t find them loud compared to small
2 strokes - especially considering the difference in power …
The mower engines also produce considerable fan noise …

 

[skyactiv]

Briggs and Stratton did market the quieter QPT engine on a walk behind gas mower and I think initially it was on a Craftsman mower for a minute 10 years ago. Few wanted it and it was offered as Sears was going out and battery mowers started to be adopted.

 

[zfasts03]

VW air cooled beetles are loud. Makes sense.

 

[tnt_motorsports]

IMO, You should be using hearing protection anyway when you run OPE. Your hearing is precious don’t throw it away on silly things.

Imagine not being able to hear a loved one’s voice or have a simple conversation with a friend or neighbor.

Just my $0.02

 

[DemoFly]

 

[Nyati]

Because they are mostly air cooled and don't have coolant jackets to insulate the noise.

That’s why Aircooled 911s at 8K RPM sound so bitchin’

 

[The_Eric]

You're missing the point. Water cooled engines are quieter because they have water passages instead of fins on the head(s) and the water (coolant) dissipates heat and also sound.

Air cooled engines radiate heat via the fins, right? Heat is a form of energy.. sound is another form of energy - it stands to reason that the same thing that is effective at shedding waste energy in the form of heat is also effective at radiating energy in the form of sound. Hence air cooled small engine are loud in spite of fancy mufflers

 

[repairman54]

Back in the day of high performance 2 strokes, ones with large 1'' long cooling fins on the heads and no cooling fans aka free air motors, they used to put rubber blocks between the fins to dampen down the ''ringing'' those fins made.

 

[mikeduf]

Well I will chime in because this hits a sore spot with me. I live in Suburbia and on Friday it appears that all of my surrounding homes have gardeners that are running the whiny two strokes and lawn mowers at Full Throttle constantly for at least 4 hours, then of course the blowers come out and they blow the crap from one side of the street to the other. Here in California all gardeners are required to use Electric equipment. My Gardener unrelated to the others actually uses a sound deadening Muffler that lowers the frequency of the mower and blowers. They're out there. But like somebody else said it's $$$

 

[The motor guy]

Well I will chime in because this hits a sore spot with me. I live in Suburbia and on Friday it appears that all of my surrounding homes have gardeners that are running the whiny two strokes and lawn mowers at Full Throttle constantly for at least 4 hours, then of course the blowers come out and they blow the crap from one side of the street to the other. Here in California all gardeners are required to use Electric equipment. My Gardener unrelated to the others actually uses a sound deadening Muffler that lowers the frequency of the mower and blowers. They're out there. But like somebody else said it's $$$

I live more out in a rural area where everyone has like 2 acres atleast. In the summertime that's all you hear are people running a lawn mower all week almost

 

[ARCOgraphite]

Our Church's Lawn-Boy ran the exhaust under the deck, I thought it was pretty quiet - or it had a less irritating drone than a Briggs 4-stroke.

Mufflers? Cost and weight for a hand held device. Then weight and cost snowballs, as with a big silencer now you need to add heat shields with an air gap over the muffler can.

Good ole Lawn-Boy

 

[jeepman3071]

With most small engines the noise is coming from the rotating assembly itself, not the exhaust.