Mower Noise

[Auto Doc's]

I live out in the rural country where quiet exhaust on equipment is optional most of the time. ()

Trying to make an engine quieter means introducing more back pressure which in turn reduces power.

You want a large (27+HP) petrol engine that is quiet?

 

[Skippydiesel]

I live out in the rural country where quiet exhaust on equipment is optional most of the time. ()

Its realy great when the piece & relative quite, of the countryside is shattered by the noise of motorcycles - why would I consider other equipment to be any less intrusive. Even tractors are much quieter (in & out) than when I started in agriculture 50 years ago

Trying to make an engine quieter means introducing more back pressure which in turn reduces power.

Most modern engines are designed to operate with a certain level of back pressure. A correctly matched muffler will preserve the required pressure, while significantly redusing dB's. Back pressure does not necessarily reduce hp. If removed from an engine designed to run with it, will shorten its service life.

You want a large (27+HP) petrol engine that is quiet?

Maaate! I want a 500 hp tractor to be as quite as current technology will deliver.

Loud noise is a pollutant. Why would you not want to reduce it, where practical to do so?

 

[GearHead36]

IMO, all engines of a given year have about the same noise. The EPA sets noise level limits, and all mfrs meet those limits, but no mfr goes beyond that. Except maybe Honda, when Honda made gas engines. Different year engines may be quieter than others if the noise limit changes.

 

[StarTech]

Trying to make an engine quieter means introducing more back pressure which in turn reduces power.

There is a technology available that simple has not been applied to small engine exhaust systems. It is the use of sound to cancel sound without inducing more back pressure. It is the same technology used in turbo mufflers.

Matter of fact when I installed a turbo on my '79 Malibu I actually got a complaint from the next door neighbor that it was too quite. It was part of my conversion to increase the highway mileage from 16 mpg to 33 mpg with better acceleration. The same came over and ask me to start the car. Well I couldn't as it was already running. He said you got to be kidding until I raised to hood and show him the running engine.

So yes the exhaust can be quite if they really tried without a reduction in hp.