The reason you see them in tractor pulls, is because they give speed instead of power like a four stroke. you will also find them in almost anything out there but Mac's and Cats because they build there own. They are also easier to work on and tuning is a breeze.
At 07:38 AM 9/23/2007, you wrote: >haven't heard of such, but it wouldn't surprise me. Detroits don't get put >in anything but Freightliners now, Detroit is owned by Freightliner, who is >owned by Daimler Chrysler. >Michael > > >_____ > >From: ><mailto:blindhandyman%40yahoogroups.com>[email protected] > [mailto:[EMAIL PROTECTED] >On Behalf Of robert moore >Sent: Saturday, September 22, 2007 23:58 >To: <mailto:blindhandyman%40yahoogroups.com>[email protected] >Subject: RE: [BlindHandyMan] What is the Difference Between a Two Stroke and >Four Stroke Engine? > >Ray Great post. >The article said that you will never see a 2 stroke in a car. While that may >be true there is at least one automotive acception to this. I will accept >some clarification from any diesel man on the list. There is a diesel engine >out there that is a 2 stroke engine that is used in semmy trucks. >As I recall I think it is the Detroit motor and I am not sure but I seem to >recall that it may be used in some of the Peter built trucks. >That engine is killer in a truck pull. > >-----Original Message----- >From: blindhandyman@ <mailto:blindhandyman%40yahoogroups.com> >yahoogroups.com [mailto:blindhandyman@ ><mailto:blindhandyman%40yahoogroups.com> yahoogroups.com]On >Behalf Of Ray Boyce >Sent: Tuesday, September 25, 2007 7:54 PM >To: blindhandyman@ <mailto:blindhandyman%40yahoogroups.com> yahoogroups.com >Subject: [BlindHandyMan] What is the Difference Between a Two Stroke and >Four Stroke Engine? > >To understand the mechanical differences between a two stroke and four >stroke engine, lets first consider how the four stroke engine works. The >four strokes >are: > >Intake: The piston travels down the cylinder while the intake >valve >is opened to allow a mixture of fuel and air to enter the combustion >chamber. > >Compression: The intake valve is closed and the piston travels back up the >cylinder thereby compressing the gasses. > >Combustion: The >spark plug >ignites the compressed gas causing it to explode, which forces the piston >down. > >Exhaust: The piston rises up the cylinder as the exhaust valve is opened, >allowing the piston to clear the chamber to start the process over. > >Each time the piston rises and falls it turns the crankshaft that is >responsible for turning the wheels. This is how fuel is converted into >forward motion. > >Of note here is that the spark plug only fires once every other revolution. >Also, there is a sophisticated set of mechanisms working in synchronization >to create the four strokes. A camshaft must alternately tip a rocker arm >attached either to the intake or exhaust valve. The rocker arm returns to >its >closed position via a spring. The valves must be seated properly in the >cylinder head to avoid compression leaks. In other words, a symphony of >mechanical >events occurs. > >In the two stroke engine, all four events are integrated into one simple >downward stroke, and one upward stroke. Two strokes. Intake and exhaust are >both >integrated into the compression and combustion movement of the piston, >eliminating the need for valves. This is accomplished by an inlet and >exhaust port >in the wall of the combustion chamber itself. As the piston travels downward >from combustion, the exhaust port is exposed allowing the spent gasses to >rush out of the chamber. The downward stroke also creates suction that draws >in new air/fuel through an inlet located lower in the chamber. As the piston >rises again, it blocks off the inlet and port, compressing the gasses at the >top of the chamber. The spark plug fires and the process starts over. >Significantly, >the engine fires on every revolution, giving the two stroke its power >advantage. > >However, at the lowest point of travel of the piston when the chamber is >filling with fuel/air, the exhaust port exposed above allows some >fuel/gasses to >escape the chamber. This is easily seen with an outboard motorboat, evident >by the multicolored >oil slick >surrounding the engine, but it happens with all two stroke engines. This - >along with burning oil -- creates pollution and fuel-efficiency issues. > >For these reasons, two stroke engines are reserved for intermittent use, >where weight-to-power ratio or orientation issues are important and where >mileage >isn't primary. Meanwhile manufacturers are looking for ways to add >advantages to four stroke motors, making them smaller, lighter and more >robust. > >To further understand the difference between a two stroke and a four stroke >engine let us consider the advantages and disadvantages. > >Advantages of the two stroke: >. Has more get-up-and-go because it fires once every revolution, giving it >twice the power of a four stroke, which only fires once every other >revolution. >. Packs a higher weight-to-power ratio because it is much lighter. >. Is less expensive because of its simpler design. >. Can be operated in any orientation because it lacks the oil sump of a four >stroke engine, which has limited orientation if oil is to be retained in the >sump. > >These attributes make two stroke engines very popular for a variety of uses >from dirt bikes, mopeds, >jet skis, >and small >outboard motors, >to lawn and garden equipment such as mowers, edgers, >leaf blowers, >chain saws and hedge trimmers. > >But there are other differences between the two stroke and four stroke >engines that aren't so favorable, which is why you won't see two stroke >engines in >cars. > >Disadvantages of the two stroke: >. Faster wear and shorter engine life than a four stroke due to the lack of >a dedicated lubricating system. >. Requires special two stroke oil ("premix") with every tank of gas, adding >expense and at least a minimal amount of hassle. >. Heavily pollutes because of the simpler design and the gas/oil mixture >that is released prior to, and in the exhaust (also creates an unpleasant >smell). >. Is fuel-inefficient because of the simpler design, resulting in poorer >mileage than a four stroke engine. >. Has a high- >decibel >whine that may exceed legal noise limits in some areas, depending on the >product and local applicable laws. > >Before purchasing a two stroke product you might check with your local >municipality to see if any restrictions apply. > >[Non-text portions of this message have been removed] > >[Non-text portions of this message have been removed] > > Tim trouble "Never offend people with style when you can offend them with substance." --Sam Brown Blindeudora list owner. To subscribe or info: http://www.freelists.org/webpage/blindeudora
