Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your Flat Engine shopping experience:
1. Compare - without doubt the biggest advantage that the Flat Engine offers shoppers today is the ability to compare thousands of Flat Engine at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.
2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about
3. Testimonials - don't know anybody that has bought a Flat Engine? Wrong! If the Flat Engine is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.
4. Questions - Got a question about Flat Engine then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....
5. Reputation - Never heard of the company selling Flat Engine? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about Flat Engine and build up a picture of their reputation for sales, returns, customer service, delivery etc.
6. Returns - still worried that even after all of the above your Flat Engine wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.
7. Feedback - happy with your Flat Engine then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.
8. Security - check for the yellow padlock on the Flat Engine site before you buy, and the s after http:/ /i.e. https:// = a secure site
9. Contact - got a question about Flat Engine, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.
10. Payment - ready to pay for your Flat Engine, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.
A
flat engine is an
internal combustion engine with pistons that are all relatively horizontal. A straight engine canted 90 degrees from straight up is a flat engine, as is one in which the
cylinder (engine)s are arranged in two banks on either side of a single
crankshaft. In both configurations, the motion of all the pistons is in the horizontal plane.
German engineer
Karl Benz patented his design for the first internal combustion engine with horizontally opposed
pistons in 1896. There are two main types of these engines:
- The boxer engine (also known as a horizontally opposed engine) in which the corresponding pistons reach top dead centre simultaneously. Boxer engines should not be confused with opposed piston engines, which use a completely different concept.
- The 180° V engine, in which corresponding pistons share a crank pin, and thus each will reach top dead centre half a crankshaft revolution after the other. Flat engines with more than eight cylinders are most commonly V engines.
Configuration
Flat engines are more compact than in-line engines, and have a lower
center of gravity than any other common configuration. Automobiles and
motorcycles powered by a flat engine generally have a lower center of gravity, giving better stability and control. These engines, however, are also wider than more traditional configurations and are more expensive to build. The extra width may cause problems fitting the engine into the engine bay of a front-engined car owing to the interference with the steering wheels, and create cornering problems for a motorcycle.
The flat configuration also fits very well with
air cooling and aircraft engines. Air-cooled designs such as in the VW Beetle used a
flat-4, as did the Porsche Porsche 356 and
Porsche 912. The
Chevrolet Corvair used
Chevrolet Corvair engine, a rarity in American designs. Both the older and newer models of the
Porsche 911 use a
flat-6, at first air cooled but later models are water-cooled. These automobiles situate the engine in the rear rather than the front, where its width does not interfere with the steering of the front wheels; the use of air-cooling obviates the need for connecting the engine to a radiator, and also reduces the weight even more.
Front-mounted air-cooled
flat-twin engines were used by Citroën in their model
Citroën 2CV and its derivatives, while the
Citroën GS used a
flat-4, and a
flat-6 was proposed for the Citroën DS, but rejected. BMW uses an air-cooled flat-twin in many of their
motorcycles.
Boxer engines
Boxer engines probably got their name because the pistons of the motor, when observed from the top, resemble the fists of a boxer pummeling his opponent. Boxer engines of up to eight cylinders have proved highly successful in both
automobiles and motorcycles, and continue to be popular for light aircraft engines.
One benefit of using a boxer engine versus a V-engine is that the design provides good balance because each piston's momentum is counterbalanced by the corresponding piston movement of the opposite side. Boxers are one of only four layouts that have a natural dynamic balance; the others being the
straight-6, the
V12 engine and the
wankel engine. These engines can run very smoothly and free of vibrations with a four-stroke cycle and do not require a balance shaft or counterweights on the crankshaft to balance the weight of the reciprocating parts, which are required in other engine configurations. (Note that this is true of all boxer engines regardless of the number of cylinders, but not true for all V and straight, or inline engines.)
Boxer engines tend to produce more noise than inline and V-engines because valve clatter is not so well dampened due to lack of covering by air-filters and other components, and produce a larger torsional vibration than a V-engine, and so, tend to require a larger flywheel. They have a characteristic smoothness throughout the rev range and, combined with the mounting position immediately ahead of the rear axle, offer a low center of gravity and more neutral handling.
Notable boxer engines
- In 1896, Karl Benz invented the first internal combustion engine with horizontally opposed pistons
- In 1923 Max Friz designed the first BMW motorcycles, choosing a 500cc boxer engine and unit transmission with shaft drive
- The Volkswagen air cooled engine used in the Volkswagen Beetle, SP2 and Karmann Ghia, and later developed further for the Volkswagen Type 2(Bus) transporters and Volkswagen Type 3 cars
- The air-cooled flat-2 "foot-warmer" motorcycles produced for many years by BMW motorcycles, and as of 2005 now back in their range by popular demand after an attempt to discontinue the design
- The Citroën 2CV and Panhard air-cooled flat-2 engines, both influenced by the flat-2s of BMW
- The air-cooled Chevrolet Corvair flat-6
- The flat-4 engines in Alfa Romeo's Alfasud, Alfa Romeo Sprint, 33 and early versions of the 145 (last of the line was a 1712 cc flat four, 16 valves, producing up to 137bhp)
- The water-cooled front-mounted flat-4 and flat-6 engines used by Subaru in all of its mid-sized cars; Subaru refers to these as boxer engines in publicity commentary, and include a variety of naturally aspirated and turbo driven engines; in their turbo engines from 1984 to current, both closed and semi-closed short blocks have been used
- The water-cooled SOHC 1832cc flat-6 as fitted to the Honda Goldwing
- The air-cooled flat-4, flat-6, flat-8 and flat-12 engines were used for many years in early Porsche#Models
- The water-cooled flat-6 engines in the Porsche Boxster, Porsche Cayman and later Porsche 911 models
180° V-engines
Flat V engines are used in performance and racing cars, normally a 180 degree V12.
Ferrari used a 180° version of the
Ferrari Colombo engine V12 in the
Ferrari Testarossa and Ferrari Berlinetta Boxer models.
See also
Flat engine designs
Other engine designs
A
flat engine is an internal combustion engine with pistons that are all relatively horizontal. A
straight engine canted 90 degrees from straight up is a flat engine, as is one in which the cylinder (engine)s are arranged in two banks on either side of a single crankshaft. In both configurations, the motion of all the pistons is in the horizontal plane.
German engineer Karl Benz
patented his design for the first internal combustion engine with horizontally opposed
pistons in
1896. There are two main types of these engines:
- The boxer engine (also known as a horizontally opposed engine) in which the corresponding pistons reach top dead centre simultaneously. Boxer engines should not be confused with opposed piston engines, which use a completely different concept.
- The 180° V engine, in which corresponding pistons share a crank pin, and thus each will reach top dead centre half a crankshaft revolution after the other. Flat engines with more than eight cylinders are most commonly V engines.
Configuration
Flat engines are more compact than in-line engines, and have a lower center of gravity than any other common configuration.
Automobiles and motorcycles powered by a flat engine generally have a lower center of gravity, giving better stability and control. These engines, however, are also wider than more traditional configurations and are more expensive to build. The extra width may cause problems fitting the engine into the engine bay of a front-engined car owing to the interference with the steering wheels, and create cornering problems for a motorcycle.
The flat configuration also fits very well with air cooling and
aircraft engines. Air-cooled designs such as in the
VW Beetle used a flat-4, as did the Porsche
Porsche 356 and
Porsche 912. The
Chevrolet Corvair used Chevrolet Corvair engine, a rarity in American designs. Both the older and newer models of the
Porsche 911 use a flat-6, at first air cooled but later models are water-cooled. These automobiles situate the engine in the rear rather than the front, where its width does not interfere with the steering of the front wheels; the use of air-cooling obviates the need for connecting the engine to a
radiator, and also reduces the weight even more.
Front-mounted air-cooled
flat-twin engines were used by
Citroën in their model
Citroën 2CV and its derivatives, while the Citroën GS used a flat-4, and a
flat-6 was proposed for the
Citroën DS, but rejected.
BMW uses an air-cooled flat-twin in many of their
motorcycles.
Boxer engines
Boxer engines probably got their name because the pistons of the motor, when observed from the top, resemble the fists of a boxer pummeling his opponent. Boxer engines of up to eight cylinders have proved highly successful in both
automobiles and motorcycles, and continue to be popular for light aircraft engines.
One benefit of using a boxer engine versus a V-engine is that the design provides good balance because each piston's momentum is counterbalanced by the corresponding piston movement of the opposite side. Boxers are one of only four layouts that have a natural dynamic balance; the others being the straight-6, the V12 engine and the
wankel engine. These engines can run very smoothly and free of vibrations with a four-stroke cycle and do not require a balance shaft or counterweights on the crankshaft to balance the weight of the reciprocating parts, which are required in other engine configurations. (Note that this is true of all boxer engines regardless of the number of cylinders, but not true for all V and straight, or inline engines.)
Boxer engines tend to produce more noise than inline and V-engines because valve clatter is not so well dampened due to lack of covering by air-filters and other components, and produce a larger torsional vibration than a V-engine, and so, tend to require a larger flywheel. They have a characteristic smoothness throughout the rev range and, combined with the mounting position immediately ahead of the rear axle, offer a low center of gravity and more neutral handling.
Notable boxer engines
- In 1923 Max Friz designed the first BMW motorcycles, choosing a 500cc boxer engine and unit transmission with shaft drive
- The Volkswagen air cooled engine used in the Volkswagen Beetle, SP2 and Karmann Ghia, and later developed further for the Volkswagen Type 2(Bus) transporters and Volkswagen Type 3 cars
- The air-cooled flat-2 "foot-warmer" motorcycles produced for many years by BMW motorcycles, and as of 2005 now back in their range by popular demand after an attempt to discontinue the design
- The Citroën 2CV and Panhard air-cooled flat-2 engines, both influenced by the flat-2s of BMW
- The air-cooled Chevrolet Corvair flat-6
- The flat-4 engines in Alfa Romeo's Alfasud, Alfa Romeo Sprint, 33 and early versions of the 145 (last of the line was a 1712 cc flat four, 16 valves, producing up to 137bhp)
- The water-cooled front-mounted flat-4 and flat-6 engines used by Subaru in all of its mid-sized cars; Subaru refers to these as boxer engines in publicity commentary, and include a variety of naturally aspirated and turbo driven engines; in their turbo engines from 1984 to current, both closed and semi-closed short blocks have been used
- The water-cooled SOHC 1832cc flat-6 as fitted to the Honda Goldwing
- The air-cooled flat-4, flat-6, flat-8 and flat-12 engines were used for many years in early Porsche#Models
- The water-cooled flat-6 engines in the Porsche Boxster, Porsche Cayman and later Porsche 911 models
- The engines of light private aircraft are often air-cooled flat-4s and flat-6s of the type famously made by the companies Lycoming Engines, and Continental Motors
180° V-engines
Flat
V engines are used in performance and racing cars, normally a 180 degree V12. Ferrari used a 180° version of the
Ferrari Colombo engine V12 in the
Ferrari Testarossa and
Ferrari Berlinetta Boxer models.
See also
Flat engine designs
Other engine designs
