The place to ask your "Stupid Questions" thread!!

[vader]

I thought its about time to start a thread that should have been started years ago....

I have a stupid question and didn't know where to post it....

You might think the questions is stupid but someone esle might find value in the responses given....

Like What The F*ck is a Horn ring? Is it something your seatcover puts on your horn to stop you shagging your neighbour?

But my question for the day is.....

How do you increase the Brake Specific Fuel Consumption (BSFC) on a aircooled engine?

[fig]

My stupid question is WTF is brake specific fuel consumption?

[Hubcap]

Brake specific fuel consumption (BSFC) is a measure of fuel efficiency within a shaft reciprocating engine. It is the rate of fuel consumption divided by the power produced. BSFC allows the fuel efficiency of different reciprocating engines to be directly compared.

To calculate BSFC, use the formula BSFC = Fuel rate / Power
Where:

Fuel rate is the fuel consumption in grams per second (g·s-1)
Power is the power produced in watts where P = Tω
ω is the engine speed in radians per second (rad·s-1)
T is the engine torque in newton meters (N·m)
The resulting units of BSFC are grams per joule (g·J-1)

Commonly BSFC is expressed in units of grams per Kilowatt-hour (g/kWh). The conversion factor is as follows:

BSFC(g/kWh) = BSFC(g/J) * 3.6*106
The conversion between metric and U.S. units is:

BSFC_US(Lbs/(HP*Hr)) * 608.277 = BSFC_METRIC(g/kWh)
BSFC_METRIC(g/kWh) * 0.001644 = BSFC_US(Lbs/(HP*Hr))

The Relationship Between BSFC Numbers and Efficiency
To calculate the actual efficiency of an engine requires the energy density of the fuel being used.
Different fuels have different energy densities defined by the fuels heating value. The lower heating value LHV is used for internal combustion engines efficiency calculations because the heat at temperatures below 150 °C cannot be put to use.

Some examples of lower heating values for vehicle fuels are:


Certification gasoline = 18640 BTU/lb = 0.01204 kW·h/g
Regular gasoline = 18917 BTU/lb = 0.0122225 kW·h/g
Diesel fuel = 18500 BTU/lb = 0.0119531 kW·h/g

Thus a diesel engine's efficiency = 1/(BSFC*0.0119531)
and a gasoline engine's efficiency = 1/(BSFC*0.0122225)


Use of BSFC numbers as Operating values and as a Cycle Average Statistic

BSFC [g/kWh] Any engine will have different BSFC values at different speeds and loads. For example, a reciprocating engine achieves maximum efficiency when the intake air is unthrottled and the engine is running near its torque peak. However, the numbers often reported for a particular engine are a fuel economy cycle average statistic. For example, the cycle average value of BSFC for a gasoline engine is 322 g/(kW·h), translating to an efficiency of 25%. However, efficiency for that engine can be lower or higher than this average statistic depending on the operating condition. In the case of a production gasoline engine, the most efficient BSFC is approximately 225 g/(kW·h), which is equivalent to a thermodynamic efficiency of 37%.

The Significance of BSFC Numbers for Engine Design and Class
The beauty of BSFC numbers is that they remain similar over a wide range of engine sizes. These numbers only change for different engine designs and compression ratios. For example, a small one cylinder 50cc four-stroke and a large V8 engine can both have the same BSFC number. However, engines of different classes like diesels and gasoline engines will have very different BSFC numbers.

[fig]

Thanks Hubert!

That was very enlightening. I never knew you were an engineering lecturer.

[Blitzkrieg]

What are a church key?

[Hubcap]

Geez I have lot's of question that are giving me sleepless nights - for starters


Why doesn't McDonald's sell hotdogs?
At a movie theater which arm rest is yours?
What is Satan's last name?
Why do doctors leave the room when you change? They're going to see you naked anyway.
Where does the toetag go on a dead person if they don't have toes?
If your driving a federal owned car, and you run a stop sign, is it considered a felony?
Why is there a disclaimer on the Allstate Auto Insurance commericals that says "Not available in all states"?
If you dug a hole through the center of the earth,and jumped in, would you stay at the center because of gravity?
If a person dies and then springs back to life, do they get their money back for the coffin?
If you are asked to tell the truth, the whole truth and nothing but the truth and your the main witness, what if you say "no"?
Do they bury people with their braces on?
How far east can you go before you're heading west?
How does a Real Estate company sell its office without causing confusion?
Do dentists go to other dentists or do they just do it themselves?
If, in a baseball game, the batter hits a ball splitting it right down the center with half the ball flying out of the park and the other half being caught, what is the final ruling?
If you were to get drunk in a country where the drinking limit is under 21, and went to the states and were still over the limit, could they arrest you for underage drinking even though you did not do the drinking in the states.
Why do people think that swaying their arm back and forth would change the direction of a bowling ball?
If girls with large breasts work at Hooters, then do girls with one leg work at IHOP?
Why is it that everyone driving faster than you is considered an idiot and everyone driving slower than you is a moron?
If pro and con are opposites, wouldn't the opposite of progress be congress?
Why does grape flavor smell the way it is when actual grapes don't taste or smell anything like it.
If a lesbian has sex with other women but never with another man is she still considered a virgin?
If a kid refuses to sleep during nap time, are they guilty of resisting a rest?
Is it rude for a deaf person to talk (sign) with their mouth full of food?
If its 11:30 PM Dec 31 in Texas and 12:30 AM Jan 1st in New York and you have a New York driver's license that expires Jan 2007, does that mean your license has expired?
What's the difference between normal ketchup and fancy ketchup?
If a transvesite goes missing, would youu put their face on a carton of Half and Half?
Why is the Lone Ranger called 'Lone' if he always has his Indian friend Tonto with him?
When does it stop being partly cloudy and start being partly sunny?
Are eyebrows considered facial hair?
If a baby's leg pops out at 11:59PM but his head doesn't come out until 12:01, which day was he born on?
In the song Yankee Doodle, is he calling the horse or the feather "macaroni"?
Is there a time limit on fortune cookie predictions?
Since bread is square, then why is sandwich meat round?
Do they have the word "dictionary" in the dictionary?
Can you daydream at night?
Why is it that on a phone or calculator the number five has a little dot on it?
Can crop circles be square?
If ghosts can walk through walls and glide down stairs, why don't they fall through the floor?
Is it legal to travel down a road in reverse, as long as your following the direction of the traffic?
When Atheists go to court, do they have to swear on the bible?
Why is vanilla ice cream white when vanilla extract is brown?
Can animals commit suicide?
What do you do when you see an endangered animal that is eating an endangered plant?
If a doctor suddenly had a heart attack while doing surgery, would the other doctors work on the doctor or the patient?
How can something be "new" and "improved"? if it's new, what was it improving on?
Why aren't drapes double sided so it looks nice on the inside and outside of your home?
When two people marry, they say, "you may kiss the bride". What do they say if two MEN get married?
Why is it that when we "skate on thin ice", we can "get in hot water"?
Why do people say beans beans the magical fruit when beans are vegetables?
If laughter is the best medicine, who's the idiot who said they 'died laughing'?
If money doesn't grow on trees then why do banks have branches?
Why are the little styrofoam pieces called peanuts?
Why does the Easter bunny carry eggs? Rabbits don't lay eggs.
Do siamese twins pay for one ticket or two tickets when they go to movies and concerts?
Why are they called 'Jolly Ranchers'? Who said that the ranchers were jolly?
Why does caregiver and caretaker mean the same thing?
Can a short person "talk down" to a taller person?
If a bald person works as a chef at a restaurant, do they have to wear a hairnet?
If milk goes bad if not refrigerated, does it go bad if the cow isnt refrigerated?
How fast do hotcakes sell?
Do prison buses have emergency exits?
Do astronauts change their clocks when they move over different time zones in space?
Can a black person join the kkk?
When lightning strikes the ocean why don't all the fish die?
When there's two men who "get married", do they both go to the same bachelor party?
If a guy that was about to die in the electric chair had a heart attack should they save him?
Why are there interstate highways in Hawaii?
Do Jewish vampires avoid crosses or Stars of David?
If London Bridge is standing why is there a song about it falling down?
Why is it that before 9/11 they always showed the emergency broadcast system test, and on 9/11 they never used it?
If a nursing mother had her nipples pierced would the milk come out of all three holes?
Who was Sadie Hawkins?
If a stripper gets breast implants can she write it off on her taxes as a business expense?
Why do we sing "Rock a bye baby" to lull a baby to sleep when the song is about putting your baby in a tree and letting the wind crash the cradle on the ground?
If parents say, "Never take candy from strangers" then why do we celebrate Halloween?
Do the minutes on the movie boxes include the previews, credits, and special features, or just the movie itself?
Is there ever a day that mattresses are not on sale?
What does PU stand for (as in "PU, that stinks!")?
Why do we put suits in a garment bag and put garments in a suitcase?
Can cannibals be arrested for being under the influence of alcohol (e.g. drunk-driving) if they have eaten someone who was drunk?
What is the stage of a reptile when it has eggs in it but they haven't been laid. Are they pregnant?
If Mars had earthquakes would they be called marsquakes?
Why do people never say "it's only a game" when they're winning?
If an ambulance is on its way to save someone, and it runs someone over, does it stop to help them?
Why is it called a funny bone, when if you hit it, it's not funny at all?
Do you yawn in your sleep?
Why do dogs like the smell of other dogs butts?
If a cannible was on death row could he ask for the last guy that was electricuted for his last meal?
Do Chinese people get English sayings tattooed on their bodies?
Do glow-in-the-dark objects stop glowing when somebody turns the lights on?
If you died with braces on would they take them off?
If someone has their nose pierced, have a cold, and take thier nose ring out. Does snot come out of the piercing hole?
How come lemon washing up liquid contains real lemons, but lemon juice contains artificial flavorings.
Do you wake up or open your eyes first?
Did Noah have woodpeckers on the ark? If he did, where did he keep them?
Why are builders afraid to have a 13th floor but book publishers aren't afraid to have a Chapter 11?
How do you handcuff a one-armed man?
If the FBI breaks your door down do they have to pay for it?
In some books, why do they have blank pages at the very end?
Why can't donuts be square?
Why put a towel in the dirty clothes basket if when you get out of the shower you are clean?
What happens to an irrisitable force when it hits an immovable object?
If there's a speed of sound and a speed of light is there a speed of smell?
Why do overalls have bel loops, since they are held up at the top by the straps?
Do people in prison celebrate halloween.... if so how?
Do the security guards at airports have to go through airport security when they get to work?
Why are all of the Harry Potter spells in Latin if they're English?
What do Greeks say when they don't understand something?
What happens if a queen gives birth to a pair of siamese twins? Who gets to be king?
Do all-boys schools have girls bathrooms? Conversely, do all-girls schools have boys bathrooms?
Are children who act in rated 'R' movies allowed to see them?
How come cats butts go up when you pet them?
What would happen to the sea's water level if every boat in the World was taken out of the water at the same time?
How come you never see a billboard being put up by the highway?
Do the English people eat English muffins, or are they just called muffins?
How much deeper would the ocean be if sponges didn't grow in it?
Why do they call it the Department of Interior when they are in charge of everything outdoors?
Why does Jello have a smell when you add the powder in the water, but when it "gels" the smell is gone?
Why are dogs noses always wet?
If a bee is allergic to pollen would it get the hives?
Why do people say "heads up" when you should duck?
Why is it OK for dudes to slap other dudes' asses in football, but not in any other situation?
Why does triangularly cut bread taste better than square bread?
If one man says, "it was an uphill battle," and another says, "it went downhill from there," how could they both be having troubles?
Why does a round pizza come in a square box?
At what point in man's evolution did he start wiping his ass?
Do bald people get Dandruff?
Why is it that no matter what color bubble bath you use the bubbles are always white?
Why do superheros wear their underwear on the outside of their clothes?
If you get cheated by the Better Business Bureau, who do you complain to?
When sign makers go on strike, is anything written on their signs?
Why does someone believe you when you say there are four billion stars, but check when you say the paint is wet?
Can you cry under water?
Why Does Pluto Live in a dog house, eat dog food, etc. but Goofy, who is also a dog, lives in a condo and drives a car?
If you blew a bubble in space would it pop?
Are children who use sign language allowed to talk with their mouth full?
How come all of the planets are spherical?
How did the first women ever to shave their legs know that the skin wouldn't just peel right off?
when a pregnant lady has twins, is there 1 or 2 umbilical cords?
Why doesn't Winnie the Pooh ever get stung by the bees he messes with?
Why do they put holes in crackers?
Can you still say "Put it where the sun don't shine " on a nude beach?
What do people in China call their good plates?
How come toy hippos are always blue, or purple, when real hippos are brown?
Why don't woodpeckers get headaches when they slam their head on a tree all day?
If someone owns a piece of land, do they own it all the way to the center of the earth?
If an escalotor breaks down, does it become stairs?
Why do they call him Donkey Kong if he is not a donkey?
Why do they say a football team is the 'world champion' when they don't play anybody outside the US?
Do stuttering people stutter when they're thinking to themselves?
If you put a chameleon in a room full of mirrors, what color would it turn?
What are the handles for corn on the cob called?
Why do British people never sound British when they sing?
Why do we press the start button to turn off the computer?
Do your eyes change color when you die?
Were Mary and Joseph's surname Christ before Jesus was born?
If a bunch of cats jump on top of each other, is it still called a dog pile?
Do sheep get static cling when they rub against one another?
In libraries, do they put the bible in the fiction or non-fiction section?
How old are you before it can be said you died of old age?
If K.F.C Stands for Kentucky Fried Chicken, Why do they play sweet home Alabama on the comercials?
If people with one arm go to get their nails done, do they pay half price?
What type of animal is Snuffaluffagus?
If you had a three story house and were in the second floor, isn't it possible that you can be upstairs and downstairs at the same time?
Can a hearse carrying a corpse drive in the carpool lane?
If a king is gay and marries another guy what is that guy to the royal family?
Why do they call it "getting your dog fixed" if afterwards it doesn't work anymore?
Does a 'Marks-A-Lot' marker, mark any more than a regular marker?
If you really could dig a hole to China, and you did, and you fell in, would you stop in the middle because of gravity?
If the funeral procession is at night, do folks drive with their headlights off?
What happens when you put a lightsaber in water?
On Gilligan's Island, how did Ginger have so many different outfits when they were only going on a 3 hour tour?
If I had my legs amputated, would I have to change my height and weight on my driver's license?
If nobody buys a ticket to a movie do they still show it?
How do you tell when you run out of invisible ink?
Do movie producers still say lights, camera, and action when it is a dark scene?
What do you call male ballerinas?
How does Freddy Kruger wipe his butt?
Why people are so scared of mice,which are much smaller than us, when no one seems to be scared of Micky Mouse, who is bigger than us?
Why are the numbers on a calculator and a phone reversed?
Why are plastic bears the only animal you can get honey from? Why can't you get honey from a plastic bee?
Can bald men get lice?
When your photo is taken for your driver's license, why do they tell you to smile? If you are stopped by the police and asked for your license, are you going to be smiling?
Do butterflies remember life as a caterpillar?
If you undergo chemotherapy do you lose your pubic hairs?
Why do people constantly return to the refrigerator with hopes that something new to eat will have materialized?
Does the postman deliver his own mail?
Why does toilet bowl cleaner only come in the color blue?
What happens when you put hand sanitizer on a place other then your hand?
Why are women and men's shoe sizes different?
Can you "stare off into space" when you're in space?
Where do people in Hell tell other people to go?
Is "vice-versa" to a dyslexic just plain redundant?
How come you can kill a deer and put it up on your wall. but it's illegal to keep one as a pet?
Why do we say we're head over heels when we're happy? Isn't that the way we normally are?
If prunes are dehydrated plums, where does prune juice come from?
Is it appropriate to say "good mourning" at a funeral?
If there's an exception to every rule, is there an exception to that rule?
When you're caught "between a rock and a hard place", is the rock not hard?
Was Jesus a virgin when he died?
Why is there a light in the fridge and not in the freezer?
Doesn't a lightning rod on top of church show a lack of faith?
Who coined the phrase, 'coined the phrase?'
If there were a thousand seaguls in an airplane while its flying, each weighing two pounds a piece, but they were all flying in the airplane, would the airplane weigh 2000 pounds more?
If you soak a raisin in water, does it turn back into a grape?
How important does a person have to be before they are considered assassinated instead of just murdered?
Why do they call steam rollers, steam rollers? They don't produce, get rid of, or have anythong to do with steam
What is another word for "thesaurus"?

[Blitzkrieg]

Nice one Hubcap!

[Pine]

My stupid question: If you fail to pay your excorcist's bill - do you get RE-posessed?

[bugspray]

You guys kinda sorta killed vaders idea hey. Hahahaha.

[vader]

Par for the course....

[vader]

Here is why I asked.....

I’m sure we can find a use for them somewhere.


Maximum power: 108,920 hp at 102 rpm
Maximum torque: 5,608,312 lb/ft at 102rpm




The Wartsila-Sulzer RTA96-C turbocharged two-stroke diesel engine is the most powerful and most efficient prime-mover in the world today. The Aioi Works of Japan 's Diesel United, Ltd built the first engines and is where some of these pictures were taken. It is available in 6 through 14 cylinder versions, all are inline engines. These engines were designed primarily for very large container ships. Ship owners like a single engine/single propeller design and the new generation of larger container ships needed a bigger engine to propel them. The cylinder bore is just under 38" and the stroke is just over 98". Each cylinder displaces 111,143 cubic inches (1820 liters) and produces 7780 horsepower. Total displacement comes out to 1,556,002 cubic inches (25,480 liters) for the fourteen cylinder version.
Some facts on the 14 cylinder version:

Total engine weight: 2300 tons (The crankshaft alone weighs 300 tons.)

Length: 89 feet

Height: 44 feet

Maximum power: 108,920 hp at 102 rpm

Maximum torque: 5,608,312 lb/ft at 102rpm
Fuel consumption at maximum power is 0.278 lbs per hp per hour (Brake Specific Fuel Consumption). Fuel consumption at maximum economy is 0.260 lbs/hp/hour. At maximum economy the engine exceeds 50% thermal efficiency. That is, more than 50% of the energy in the fuel in converted to motion.
For comparison, most automotive and small aircraft engines have BSFC figures in the 0.40-0.60 lbs/hp/hr range and 25-30% thermal efficiency range.
Even at its most efficient power setting, the big 14 consumes 1,660 gallons of heavy fuel oil per hour.
A cross section of the RTA96C:

The internals of this engine are a bit different than most automotive engines.
The top of the connecting rod is not attached directly to the piston. The top of the connecting rod attaches to a "crosshead" which rides in guide channels. A long piston rod then connects the crosshead to the piston.
I assume this is done so the the sideways forces produced by the connecting rod are absorbed by the crosshead and not by the piston. Those sideways forces are what makes the cylinders in an auto engine get oval-shaped over time.
Installing the "thin-shell" bearings. Crank & rod journals are 38" in diameter and 16" wide:


The crank sitting in the block (also known as a "gondola-style" bedplate). This is a 10 cylinder version. Note the steps by each crank throw that lead down into the crankcase:

A piston & piston rod assembly. The piston is at the top. The large square plate at the bottom is where the whole assembly attaches to the crosshead:

Some pistons: And some piston rods:



The "spikes" on the piston rods are hollow tubes that go into the holes you can see on the bottom of the pistons (left picture) and inject oil into the inside of the piston which keeps the top of the piston from overheating. Some high-performance auto engines have a similar feature where an oil squirter nozzle squirts oil onto the bottom of the piston.
The cylinder deck (10 cylinder version). Cylinder liners are die-cast ductile cast iron. Look at the size of those head studs!:

The first completed 12 cylinder engine:

[vader]

too lazy to post the picks sorry Blitz...
Mybe TonyZ will do it..

This is something he sent me and I got to wondering about BFSC as this ships engines efficiency exceeds 50% thermal efficiency @ max economy....

[vader]

You guys kinda sorta killed vaders idea hey. Hahahaha.

It is also a good place to post those stupid questions like, "How do I get access to the Offered section?"

[Chris]

Is the Darkside cursed?

[vader]

Is the Darkside cursed?

BWWWWWHHHAHAHAHAHAHAHAHAHA F*ck thats funny....














Funny But True....