Mufflers

A muffler (or silencer in British English) is a device for reducing the amount of noise emitted by the exhaust of an internal combustion engine. A US Patent for an Exhaust muffler for engines was granted to Milton and Marshall Reeves in 1897. The first muffler was invented by Hiram_Percy_Maxim to silence Guns. When used on internal combustion engines, the engine Exhaust blows out through the muffler.


The patent for an Exhaust muffler for engines was awarded to Milton O. Reeves and Marshall T. Reeves of Columbus, Indiana of the Reeves Pulley Company on 11 May 1897. US Patent Office application No 582485 states that they have invented certain new and useful Improvements in Exhaust-Mufflers for engines ....

Mufflers by Brand

Parts related to small engine mufflers and exhaust parts:  
Gaskets  

Description

Mufflers are installed within the exhaust system of most internal combustion engines, although the muffler is not designed to serve any primary exhaust function. The muffler is engineered as an acoustic soundproofing device designed to reduce the loudness of the sound pressure created by the engine by way of Acoustic quieting. The majority of the sound pressure produced by the engine is emanated out of the vehicle using the same piping used by the silent exhaust gases absorbed by a series of passages and chambers lined with roving fiberglass insulation and/or resonating chambers harmonically tuned to cause destructive interference wherein opposite sound waves cancel each other out. An unavoidable side effect of muffler use is an increase of back pressure which decreases engine efficiency. This is because the engine exhaust must share the same complex exit pathway built inside the muffler as the sound pressure that the muffler is designed to mitigate.

Some vehicle owners remove or install an aftermarket muffler when Engine tuning in order to increase power output or reduce fuel consumption because of economic or environmental concerns, recreational pursuits such as motorsport and hypermiling and/or for personal aesthetic acoustical preferences. Although the legality of altering a motor vehicles OEM exhaust system varies by jurisdiction, in most developed parts of the world, modification of a vehicles exhaust system is usually highly regulated if not strictly prohibited.

Types and positions of mufflers
With cars, lengthwise underneath, blowing backwards at the rear
To the sides before the rear wheels.
With large diesel-powered trucks:-
Mounted vertically behind the cab
Crosswise under the front of the cab, blowing sideways.
With motorcycles:
Usually, beside the engine and rear wheel blowing backwards.
In more modern motorcycles, under the seat blowing backwards from under the back of the seat. (Under-slung)
Under-engine exhausts first reached popularity with Buell motorcycles, though by 2008 most manufacturers began using the under-engine design as well.
Motorcycle enthusiasts sometimes use the term "raygun," "drag pipes", "pea-shooter" or "hotdog-style" for the old shape of motorcycle exhaust silencer/muffler with a long straight cylindrical barrel that merged roundedly at each end into the pipe.

Additional information and source: Muffler