Carbs vs. FI -- elegance vs. precision

[adouglas]

Just saw an ad for the Labor Day vintage races at Lime Rock. I think I'll go this year. Got me thinking about machinery and the perspective that age has granted me.

I love stuff like carburetors. When FI is so much more efficient and easy, one might wonder why. It has to do with the inherent beauty of elegant solutions.

You can go down to the corner store, and for a few cents buy a digital quartz timepiece that's more accurate and reliable than the chronometers that helped explorers in the Age of Discovery circumnavigate the planet for the first time.

Or, you can invest thousands in a Rolex... an analog machine of exquisite craftsmanship and precision. A thing of intrinsic beauty, designed to solve the same problem as that cheap quartz timepiece.

From a purely functional point of view, the cheap quartz watch wins every time.

But the Rolex has soul. It has personality. It inspires passion. It is worthy of respect and admiration because it is elegant.

I feel that way about carburetors. This is a machine finely tuned and designed to precisely meter fuel, balancing it against airflow and engine demand, using nothing but aerodynamics as a modulator. There are no electronics involved.

Think about that for a moment. It is a minor miracle. It is beautiful precisely because it is an elegant, subtle solution, rather than than the cold, brute-force answer of digital technology.

An EFI system is, without doubt, better in every way from a functional standpoint. But it's BORING. It's too easy. There is no coaxing, no negotiating, no art, no development of a relationship with the machine that is rocketing you down the road at 100 mph.

[RacinNinja]

Originally Posted by adouglas

Just saw an ad for the Labor Day vintage races at Lime Rock. I think I'll go this year. Got me thinking about machinery and the perspective that age has granted me.

I love stuff like carburetors. When FI is so much more efficient and easy, one might wonder why. It has to do with the inherent beauty of elegant solutions.

You can go down to the corner store, and for a few cents buy a digital quartz timepiece that's more accurate and reliable than the chronometers that helped explorers in the Age of Discovery circumnavigate the planet for the first time.

Or, you can invest thousands in a Rolex... an analog machine of exquisite craftsmanship and precision. A thing of intrinsic beauty, designed to solve the same problem as that cheap quartz timepiece.

From a purely functional point of view, the cheap quartz watch wins every time.

But the Rolex has soul. It has personality. It inspires passion. It is worthy of respect and admiration because it is elegant.

I feel that way about carburetors. This is a machine finely tuned and designed to precisely meter fuel, balancing it against airflow and engine demand, using nothing but aerodynamics as a modulator. There are no electronics involved.

Think about that for a moment. It is a minor miracle. It is beautiful precisely because it is an elegant, subtle solution, rather than than the cold, brute-force answer of digital technology.

An EFI system is, without doubt, better in every way from a functional standpoint. But it's BORING. It's too easy. There is no coaxing, no negotiating, no art, no development of a relationship with the machine that is rocketing you down the road at 100 mph.

Indeed! It's part of the reason I race the old beasts. Raw, mechanical beauty.

[adouglas]

Dam that makes my pants fit funny.

[adouglas]

See, there's this sense of rightness that you come to appreciate. When you've been around the block enough times, you get it.

It's not about function. It's not about form.

It's about stuff that you just know, deep down, will stir someone's soul 50 years from now.

That is art. That is beauty.

[Racer x]

I love mechanical things like carbs. I have carbs on my bike because they just work. No problems at all.
My wrist watch? It is a Seiko 5 mechanical. 75 bucks on e bay. No batteries it winds itself and keeps perfect time. Like my carbs it just works. Call me old school. I don't care. The mechanical world is not any different than the electronic/ electric world. But I like the old mechanical stuff that does not use wires and batteries. Just my preference.

[RacinNinja]

Originally Posted by adouglas

See, there's this sense of rightness that you come to appreciate. When you've been around the block enough times, you get it.

It's not about function. It's not about form.

It's about stuff that you just know, deep down, will stir someone's soul 50 years from now.

That is art. That is beauty.

Dad built it in 1977. It sat collecting dust since 1980 for 32 years until I drug it out again. He built another one to match it.....sure has a good eye for bikes!

On another note, he builds em and I tune em. Suspension too. I rode his machine at the last round of racing. I had to lower the fork tubes a total of 1 3/8" in the triples until it rode right. Couple adjustments to the rear too.....we have 10 way adjustable damping units. Once it did, I turned identical lap times on it. Talk about a clone!

[Singh2jz]

[VaFish]

If I want to work on a bike, I'll take carbs. If I want to ride a bike, I'll take fuel injection.

[Bigballsofpaint]

Ill be at Limerock on friday for the qualifying Andy, maybe ill catch ya there!

FI > Carbs, but im a young whipper snapper

[adouglas]

Originally Posted by VaFish

If I want to work on a bike, I'll take carbs. If I want to ride a bike, I'll take fuel injection.

[FrugalNinja250]

I grew up with carbs, during the so-called golden years of carbs (1970's and up), and I can say this: When FI became modern mainstream I didn't look back. Most youngsters here won't remember the days when there were cabureter overhaul/tuning shops everywhere because carbs on cars required so much maintenance to keep things working smoothly with some semblance of fuel efficiency. Andy Granatelli's Tuneup Masters, anyone? He sold that business for $60M in 1986, a business that solely focused on tuneups and carb work. It was pretty common to have to take your vehicle in every 12-24 months to have work done, adjustments to compensate for wear, replacing rubber parts like the choke pull-off, adjusting or replacing the floats because they sunk, etc. It was a PITA that we were all used to until FI came around, then suddenly we had cars that ran for years needing little more than tire and oil changes. There's a reason there are no tune-up businesses left anymore.

We could now experience what it was like to not be a slave to your car's carb. Now things just work. They always work. Cold, hot, rain, shine, FI allows cars to just work, the same way, every day.

I, for one, don't regret the passing of carbs from the mainstream. They were marvelous examples of engineering with limited materials and technology, and much was achieved with that century old technology, but FI surpassed anything a carb could ever do a long time ago.

Now I need to go overhaul the carb on my mower so I can mow my lawn, something I have to do once a year. The carb on my string trimmer finally quit responding to overhauls last year so I scrapped it and went electric. The carbs on my pregen are doing ok, but I need to go back into them soon as my gas mileage has dropped into the 50's for some reason (normally I'm in the mid-to-high 60's). I'm sure some rubber or plastic bit has become dirty or worn.

I hate carbs...

[RacinNinja]

My lawnmower is 13 years old. Never touched the carb. Run regular 87 octane.

Weedeater is 10 years old. Never touched the carb. Run regular 87 octane.

Same for leafblower.

Same goes for everything else I own. Don't understand the issues some folks have, although I run nothing but Chevron fuel.

[shift957]

If it weren't for today's government regulated sh#tty fuel, I would have more love for carbs. I had a sweet all original '88 FZR400 which was dyno tuned by a friend's shop and raced at the Maxton Mile in NC. It set a land speed record with my lightweight friend piloting it for the stock 400cc class.

Six weeks after running top notch, the carb was already gumming up from the fuel. I just got sick of cleaning carbs in that bike, my KTM 640 enduro and dirt bikes. FI doesn't require any fuel additives or special care. Owning multiple bikes, I just don't care to have that hassle any longer.

That being said, if you are out riding in the middle of nowhere and your FI goes out, you're screwed. At least with the carb'ed bike you can pull it apart and clean it, adjust whatever and get going again. Knowing carbs is certainly an art. Those who know them well, swear by them.

Thanks for the well written post, adouglas!

[Racer x]

I worked on euro cars for a long long time. Ask any BMW or Mercedes owner about there check engine light.

I am not bashing fuel injection. It is great and getting better all the time. But when it first came out. Man o man did it have growing pains. Yes carbs are going the way of the dinosaurs. And that is OK I guess. But when you know how to tune carbs they are great. Just don't let them sit with ethanol in them all winter.

[Ninja Rob]

In one of my previous posts, I posted something related to this. In my experience I have only ridden 2 250's. FI and my current carburator 04 250. The FI felt smooth but automatic. My carburator ninja overall just feels more enthusiastic. It feels like it wants to be ridden. Like you said, it has soul. Those carbs have put a smile on my face everytime. I still have not gotten bored of my 250.

[Motofool]

Copied from:
https://en.wikipedia.org/wiki/Carburetor
and from:
https://en.wikipedia.org/wiki/Fuel_injection

Carburation
The first carburetor was invented by Samuel Morey in 1826.
A carburetor was invented by an Italian, Luigi De Cristoforis, in 1876. Another carburetor was developed by Enrico Bernardi at the University of Padua in 1882, for his Motrice Pia, the first petrol combustion engine (one cylinder, 121.6 cc) prototyped on 5 August 1882.

A carburetor was among the early patents by Karl Benz (1888) as he developed internal combustion engines and their components.
Early carburetors were the surface carburetor type, in which air is charged with fuel by being passed over the surface of gasoline.

In 1885, Wilhelm Maybach and Gottlieb Daimler developed a float carburetor for their engine based on the atomizer nozzle. The Daimler-Maybach carburetor was copied extensively, leading to patent lawsuits, but British courts rejected the Daimler company's claim of priority in favor of Edward Butler's 1884 spray carburetor used on his Petrol Cycle.

Hungarian engineers János Csonka and Donát Bánki patented a carburetor for a stationary engine in 1893.
Frederick William Lanchester of Birmingham, England, experimented with the wick carburetor in cars. In 1896, Frederick and his brother built the first gasoline-driven car in England: a single cylinder 5 hp (3.7 kW) internal combustion engine with chain drive. Unhappy with the performance and power, they re-built the engine the next year into a two-cylinder horizontally opposed version using his new wick carburetor design.

Carburetors were the usual method of fuel delivery for most US-made gasoline-fueled engines up until the late 1980s, when fuel injection became the preferred method. This change was dictated more by the requirements of catalytic converters than by any inherent inefficiency of carburation; a catalytic converter requires much more precise control over the fuel / air mixture, to closely control the amount of oxygen in the exhaust gases.
.........

The main disadvantage of basing a carburetor's operation on Bernoulli's Principle is that, being a fluid dynamic device, the pressure reduction in a Venturi tends to be proportional to the square of the intake air speed. The fuel jets are much smaller and limited mainly by viscosity, so that the fuel flow tends to be proportional to the pressure difference. So jets sized for full power tend to starve the engine at lower speed and part throttle. Most commonly this has been corrected by using multiple jets.
.........

Diesel's original engine injected fuel with the assistance of compressed air, which atomized the fuel and forced it into the engine through a nozzle (a similar principle to an aerosol spray). The nozzle opening was closed by a pin valve lifted by the camshaft to initiate the fuel injection before top dead centre (TDC). This is called an air-blast injection. Driving the three stage compressor used some power but the efficiency and net power output was more than any other combustion engine at that time.

Diesel engines in service today raise the fuel to extreme pressures by mechanical pumps and deliver it to the combustion chamber by pressure-activated injectors without compressed air. With direct injected diesels, injectors spray fuel through 4 to 12 small orifices in its nozzle. The early air injection diesels always had a superior combustion without the sharp increase in pressure during combustion.
........

Mechanical injection
The invention of mechanical injection for gasoline-fueled aviation engines was by the French inventor of the V8 engine configuration, Leon Levavasseur in 1902. Levavasseur designed the original Antoinette firm's series of V-form aircraft engines, starting with the Antoinette 8V to be used by the aircraft the Antoinette firm built that Levavasseur also designed, flown from 1906 to the firm's demise in 1910, with the world's first V16 engine, using Levavasseur's direct injection and producing around 100 hp (75 kW; 101 PS) flying an Antoinette VII monoplane in 1907.

The first post-World War I example of direct gasoline injection was on the Hesselman engine invented by Swedish engineer Jonas Hesselman in 1925. Hesselman engines used the ultra-lean-burn principle and injected the fuel in the end of the compression stroke and then ignited it with a spark plug, it was often started on gasoline and then switched over to run on diesel or kerosene. The Hesselman engine was a low compression design constructed to run on heavy fuel oils.

Direct gasoline injection was applied during the Second World War to almost all higher-output production aircraft powerplants made in Germany (the widely used BMW 801 radial, and the popular inverted inline V12 Daimler-Benz DB 601, DB 603, and DB 605, along with the similar Junkers Jumo 210G, Jumo 211, and Jumo 213, starting as early as 1937 for both the Jumo 210G and DB 601), the Soviet Union (Shvetsov ASh-82FN radial, 1943, Chemical Automatics Design Bureau - KB Khimavtomatika) and the USA (Wright R-3350 Duplex Cyclone radial, 1944).
Immediately following the war, hot rodder Stuart Hilborn started to offer mechanical injection for race cars, salt cars, and midget racers,[9] well-known and easily distinguishable because of their prominent velocity stacks projecting upwards from the engines on which they were used.

The first automotive direct injection system used to run on gasoline was developed by Bosch, and was introduced by Goliath for their Goliath GP700 automobile, and Gutbrod in 1952. This was basically a high-pressure diesel direct-injection pump with an intake throttle valve. (Diesels only change the amount of fuel injected to vary output; there is no throttle.) This system used a normal gasoline fuel pump, to provide fuel to a mechanically driven injection pump, which had separate plungers per injector to deliver a very high injection pressure directly into the combustion chamber.
.......

Electronic injection
The first commercial electronic fuel injection (EFI) system was Electrojector, developed by the Bendix Corporation and was offered by American Motors Corporation (AMC) in 1957. The Rambler Rebel, showcased AMC's new 327 cu in (5.4 L) engine. The Electrojector was an option and rated at 288 bhp (214.8 kW). The EFI produced peak torque 500 rpm lower than the equivalent carburetored engine. The Rebel Owners Manual described the design and operation of the new system (due to cooler, therefore denser, intake air). The cost of the EFI option was US$395 and it was available on 15 June 1957. Electrojector's teething problems meant only pre-production cars were so equipped: thus, very few cars so equipped were ever sold and none were made available to the public. The EFI system in the Rambler ran fine in warm weather, but suffered hard starting in cooler temperatures.

[Triple Jim]

Originally Posted by adouglas

I love stuff like carburetors. When FI is so much more efficient and easy, one might wonder why. It has to do with the inherent beauty of elegant solutions.

My 250 has gotten between 60 and 70 mpg since I got it last year. What kind of mileage do the much more fuel efficient injected versions of the bike get?

[Racer x]

Of all the fuel injection systems I have worked with CIS is my favorite. Back in the day it was a simple mechanical system. Electric fuel pump was and cold start valve was the only electric part. It worked great. Then they started to add stuff and it got crazy. They replaced it with better.

Before that was an electronic system with trigger points to control the injectors and before that pure mechanical injection like a diesel.

All the old Mercedes system worked well. Until the electronic stuff was added to meet emition. Then the systems needed to be completely changed.

The is my favorite of them all.

http://www.youtube.com/watch?v=a4fJAfXYxWk&sns=em

[Racer x]

On the carburetor side. I just love the fuel system on a model T Ford. Driving a model T is more like a tractor than a car. The carb is an updraft arrangement with fuel being pulled up through the manifold and it is heated by the exhaust. There is a fuel bowl at the bottom and a fuel tank below the windshield.

What today would be blinkers stalks on the steering colume are the two levers that control timing and throttle. You pull down for more air and to advance the timing. To increase the fuel mixture there is a knob that today would be the glove box knob. That is the main jet and controls mixture.

So to drive a Model T. First there are three pedals on the floor. Right ( what would today be the gas pedal )is reverse. In the center is brake. And to the left is high low on the trans. Far left is a large lever. That is the parking brake and neutral.

So once you set the timing and fuel you pull the left hand lever . This locks the rear brakes and moved the left foot pedal to neutral. They are a strap type brake going to the rear wheels. The foot brake goes to a band inside the trans.
Once the fuel and timing are set you go out front and crank the engine. You have to be careful how that is done. And it is set up on compression with the key off.

Now you turn on the key and give the engine a quick crank and the engine starts.

Now you run back to the inside and get behind the wheel. You give it some more gas by turning the knob on the passenger side to open the jet some and you open the throttle by pulling down on the right side blinker shaft. Once the engine is purring like a kitten you put one foot on the middle pedal to apply the brakes. You put the other foot on the left pedal to hold it in the center of its travel. Down is low gear up is high gear and neutral is between.

Now you are ready to go. You release the left hand lever and open the throttle while pushing down on the left pedal. This puts in in low gear and off you go. As soon as you are moving give it some more throttle and let up on the left pedal. Now start advancing the timing and increase the fuel volume.

Once under way you are constantly adjusting everything. If a hill is coming you open the main jet and throttle to get some speed and start to pull back timing as you go up hill. On the early model you sometimes had to back up hill because the tank was under the seat. And two steep a hill would starve the carb for fuel. You really had to know the vehicle and you became connected to the engine with experience.

There are four million still on the road 100 years after they first made them.

https://goo.gl/images/QeIG3F

[Triple Jim]

And I still use my 1936 Evinrude Elto Ace, a 1.4 hp 2-stroke rope-started outboard motor. There is no throttle, and the carb has a spring loaded poppet valve on the air inlet to create the engine's intake valve. A lever controls a needle valve to set the mixture. The breaker points are on a plate that you can rotate with a lever, so you can control the engine's spark timing, and hence speed, from barely running to full speed.

For reverse, you move the timing lever over to the other side of top dead center and wrap the rope around the flywheel the other way. Giving it a pull starts it in the reverse direction, and you back up the boat. To stop the engine, you push a button on the carb that keeps the poppet valve from closing.

Having the spark lever and mixture lever in just the right places is necessary for starting, so for theft prevention, you can just mess up the lever positions, and unless the boat thief knows that engine intimately, he'll pull the rope all day and never get it running.

[Jono]

And then there are these things...

[CaliGrrl]

A Zero! In the wild!

Coolness.