How a Car Engine Works(jacoboneal.com)
jacoboneal.com
How a Car Engine Works
http://jacoboneal.com/car-engine/
46 comments
Direct injection implies the fuel is injected at the top of compression stroke, but the animation shows the fuel being added during the intake stroke. This is just an inaccurate drawing showing the injector attached to the cylinder rather than the intake manifold.
Interestingly, this could be a drawing of a ultra modern gas direct injection system running in classic mode. Ford's EcoTech will, under certain conditions, operate like this picture, though I am sure that is not what the author had in mind.
Interestingly, this could be a drawing of a ultra modern gas direct injection system running in classic mode. Ford's EcoTech will, under certain conditions, operate like this picture, though I am sure that is not what the author had in mind.
Beat me to it!
This totally amazed me when I started working on cars. Both carburetors and direct injection creates a mixture of gasoline and air BEFORE this mixture enters the cylinder. Direct injection now seems like a misnomer ;) It makes a lot of sense if you think about the incredibly violent conditions inside the cylinder head though. I'm always surprised that spark plugs survive as easily as they do, I imagine a high accuracy injector nozzle in that situation would not last as long as current injectors. Has anyone done a true direct-injection design?
Jacob, can you update the drawing slightly? "The fuel injectors spray gas into the cylinder..." is incorrect, it should be closer to "The fuel injectors spray gas into the intake manifold where it mixes with air before being sucked into the cylinder"
This totally amazed me when I started working on cars. Both carburetors and direct injection creates a mixture of gasoline and air BEFORE this mixture enters the cylinder. Direct injection now seems like a misnomer ;) It makes a lot of sense if you think about the incredibly violent conditions inside the cylinder head though. I'm always surprised that spark plugs survive as easily as they do, I imagine a high accuracy injector nozzle in that situation would not last as long as current injectors. Has anyone done a true direct-injection design?
Jacob, can you update the drawing slightly? "The fuel injectors spray gas into the cylinder..." is incorrect, it should be closer to "The fuel injectors spray gas into the intake manifold where it mixes with air before being sucked into the cylinder"
There are true common-rail direct cylinder injection gasoline engines out there. They're not so common though, since there aren't as many advantages to it compared to a diesel engine.
Cars marketed as GDI, such as the Ford EcoBoost, inject directly in the cylinder.
Cars marketed as GDI, such as the Ford EcoBoost, inject directly in the cylinder.
Are you sure this is a direct injection? I'm seeing the injector directly behind the inlet valves which would make it multi point.
I just took a close look at it, and I think you're right. It's not the easiest thing to see due to the wireframe, but with a second look it does appear that the injectors are just behind the valve.
So yes, it's multi-point injection, rather than direct injection which is the new hotness for gasoline. Formula 1 will allow it from next year with the new V6 formula!
So yes, it's multi-point injection, rather than direct injection which is the new hotness for gasoline. Formula 1 will allow it from next year with the new V6 formula!
I'm currently rebuilding a 2.0 TDCI engine .. an interesting feature is the crowns of the pistons. With direct injection the fuel is aimed at specifically shaped depressions in the piston crowns which causes vortices between the atomised fuel and air improving the mix for a cleaner burn.
V6 formula!?!? Validating my decision several years ago to quit following F1. ;-)
V6 turbo with energy recovery on the turbo itself. They're also allowed to use that energy to re-spool the turbo to eliminate lag. They've also hugely bumped the KERS and built it in to the throttle map - no more button for it.
I can't remember the exact figures, but it means that they have so much torque when they go full throttle it'll spin the wheels at almost any speed.
I'm looking forward to them slipping around the corners again. Also to engines blowing up, since that doesn't happen much due to 5 year old engine designs.
I can't remember the exact figures, but it means that they have so much torque when they go full throttle it'll spin the wheels at almost any speed.
I'm looking forward to them slipping around the corners again. Also to engines blowing up, since that doesn't happen much due to 5 year old engine designs.
For me it was when they kept changing the rules (in 2005) just to ensure that Schumacher lost. Haven't looked back since. I hear they can't even refuel these days (the horror!)
Which is actually very accurate. Modern injectors are positioned to spray fuel on the back of the valve. This helps cool the valve which protects them from heat-related damage, and also helps vaporize the fuel.
The other difference is Diesel engines ignite the fuel by compressing it rather than with a spark.
(Also Diesel is the engine type not the fuel http://en.wikipedia.org/wiki/Diesel_engine)
(Also Diesel is the engine type not the fuel http://en.wikipedia.org/wiki/Diesel_engine)
Well they both work on compression, diesels simply rely on it more than gasoline engines.
Diesel engines work on what's called adiabatic compression heating. In other words, the compression causes the air to heat to a point higher than the ignition point of the fuel. Diesel engines usually use glow plugs to compensate for the lack of adiabatic compression heating when the engine is cold.
Diesel engines work on what's called adiabatic compression heating. In other words, the compression causes the air to heat to a point higher than the ignition point of the fuel. Diesel engines usually use glow plugs to compensate for the lack of adiabatic compression heating when the engine is cold.
See also the awesome fire piston, a relatively ancient technology using the same principles:
https://en.wikipedia.org/wiki/Fire_piston
https://en.wikipedia.org/wiki/Fire_piston
yep the original diesel engine was designed to run on coal dust, unlike the modern light fuel oil diesels (kerosene, jet-A, home heating oil, and diesel fuel are all very close to the same thing, differing mainly in additives).
Also note that it has a distributor, which is uncommon on new cars. New cars generally have one coil for each cylinder (or pair of cylinders that fire 360 degrees apart).
Ah, carburetors - how I hated those things. Simple in theory, yet so complicated and fickle in practice...
I do love old diesel engines with mechanical belt-driven high pressure pumps and mechanical injectors - those things were easy to fix and built to last...
I do love old diesel engines with mechanical belt-driven high pressure pumps and mechanical injectors - those things were easy to fix and built to last...
I drive a 30 year old Mercedes diesel as my primary car and it still runs like a swiss watch. You do have to adjust the valve clearance every so often, which is not necessary in a modern diesel or even ones slightly newer than mine.
If it's the 3.0 liter 5 cylinder diesel (OM617) - those are considered to be some the most reliable diesel engines ever made :-)
I drive a seven year old motorcycle and carburetors + ethanol = nightmare. A tank of gas with the ethanol admixture will often go bad enough to gum up the carbs in just a few weeks. I've had the engine stall out under me in potentially dangerous situations twice because of this. Damn corn farmer lobby.
maybe also worth noting that this is OHC and not pushrod
Hi fellow gear-heads... very cool engine graphics!
On a related note, I wanted to add that, if you are not familiar with dual-clutch transmissions [1], they are pretty interesting.
One example (many manufacturers offer this type of transmission) is the Porsche Doppelkupplungsgetriebe (or simply PDK) [2], developed by Porsche. It is essentially two gearboxes in one complete transmission package, where both gearboxes possess their own clutch. When a gear is selected in one gearbox, the next gear is pre-selected in the other gearbox. The result is a nearly-instantaneous gear change, with smooth power delivery.
[1] https://en.wikipedia.org/wiki/Dual-clutch_transmission
[2] https://www.youtube.com/watch?v=C7Zh-nQPh_8&t=33
On a related note, I wanted to add that, if you are not familiar with dual-clutch transmissions [1], they are pretty interesting.
One example (many manufacturers offer this type of transmission) is the Porsche Doppelkupplungsgetriebe (or simply PDK) [2], developed by Porsche. It is essentially two gearboxes in one complete transmission package, where both gearboxes possess their own clutch. When a gear is selected in one gearbox, the next gear is pre-selected in the other gearbox. The result is a nearly-instantaneous gear change, with smooth power delivery.
[1] https://en.wikipedia.org/wiki/Dual-clutch_transmission
[2] https://www.youtube.com/watch?v=C7Zh-nQPh_8&t=33
The new Corvette does something interesting - there's a sensor on the manual gear shift lever that predicts what gear you're going to select, and will do the rev matching for you. Result is a perfect downshift, every time.
Yep, Nissan's 370Z has had SynchroRevMatch as part of its Sport/NISMO packages for a few years now, and from what I've heard through friends it's very simple and works really well... Although it makes me wonder at what point on the spectrum does a "manual" become an "automatic"
http://en.wikipedia.org/wiki/Synchronized_down_shift_rev-mat...
http://en.wikipedia.org/wiki/Synchronized_down_shift_rev-mat...
Sometimes I do not have the right shoes on to rev match so I can see this feature being useful. I would consider a car a manual if the user has to press a clutch in before changing gears.
Right... shoes?
I haven't driven a stick regularly since high school, don't people rev match with their ears ?
I haven't driven a stick regularly since high school, don't people rev match with their ears ?
Yes right shoes. If you want to heel toe, you can't do it in your steel capped boots
http://www.youtube.com/watch?v=muxVLOaw2ik
Eh, you can revmatch without heel-toeing. I did it for years before I started driving at the track and learned how to heel-toe. You just brake enough for the turn, then let off the brake entirely and blip the throttle and drop the clutch while turning.
That's one of the major reasons the GT-R is so quick off the line and down the quarter mile.
It was the first production car with a dual-clutch transmission that was actually realistically priced, and it's still arguably the most cost-effective.
It was the first production car with a dual-clutch transmission that was actually realistically priced, and it's still arguably the most cost-effective.
Actually VW sold a dual clutch DSG transmission in the 2003 R32, years before the GTR hit the market, and for a fraction of the price. All other things the same, a dual clutch is not much faster than a properly-operated manually-clutched gearbox, but in the case of the GTR, we'll never be able to make that comparison.
>All other things the same, a dual clutch is not much faster than a properly-operated manually-clutched gearbox
Formula One drivers in the early 90s were the only ones really able to come close, with shift times between 150 and 200ms. The average person is more around 300 - 400ms when shifting aggressively. You can be faster than 300 - 400ms, but not with 100% consistency, especially on downshifts, and especially with some transmissions with odd clutch engagement points or shift levers that require more deliberate effort.
A modern DCT, like Porsche's 2nd generation PDK, has a shift time of 150ms. Porsche's 3rd generations are even faster -- the PDK-S in the new GT3 is 100ms. The version in the 918 Spyder is 50ms. All of these are perfectly rev-matched, every time.
I've driven many tremendously good manual transmissions. However, generation two PDK is good enough that after four test drives (two with a 6-speed, two with PDK + Sport Chrono) I've actually decided to order my Cayman S with PDK since it's unquestionably better. The only thing I wish is it had the "burnout/donut mode" of the 3rd gen.
Formula One drivers in the early 90s were the only ones really able to come close, with shift times between 150 and 200ms. The average person is more around 300 - 400ms when shifting aggressively. You can be faster than 300 - 400ms, but not with 100% consistency, especially on downshifts, and especially with some transmissions with odd clutch engagement points or shift levers that require more deliberate effort.
A modern DCT, like Porsche's 2nd generation PDK, has a shift time of 150ms. Porsche's 3rd generations are even faster -- the PDK-S in the new GT3 is 100ms. The version in the 918 Spyder is 50ms. All of these are perfectly rev-matched, every time.
I've driven many tremendously good manual transmissions. However, generation two PDK is good enough that after four test drives (two with a 6-speed, two with PDK + Sport Chrono) I've actually decided to order my Cayman S with PDK since it's unquestionably better. The only thing I wish is it had the "burnout/donut mode" of the 3rd gen.
I'm a little surprised. I figure most people buying a Cayman S are buying it for fun. I've never driven with a DCT, but most people who have that I've heard from generally say that manual is more fun, while DCT is better in every other respect.
Did you find DCT to be at least as fun as manual? I think I'd miss the feeling of nailing the revs perfectly on a downshift while braking for a turn on the track.
Any thoughts?
Did you find DCT to be at least as fun as manual? I think I'd miss the feeling of nailing the revs perfectly on a downshift while braking for a turn on the track.
Any thoughts?
People buy Porsches for fun or track duty. Some for both, in which I'm in the latter crowd. I autocross my cars, and do DEs -- my current MX-5 has been on at least 13 different race courses in the country, including some of the very best (Watkins Glen, Mid-Ohio, Road Atlanta, Road America, Infineon, Laguna Seca, Sebring, VIR, Lime Rock). It's also my daily when I need to use a car to commute.
As for the Cayman S, it's a damn serious car. My load out hits 60 in 4.1-4.2s with launch control, and the 1/4 mile in around 12.6-12.7 @ 110mph (and 175mph in ~49 seconds). A set of Michelin Pilot Super Sports will get it to hold around 1.1g of lateral grip (sustained, not peak). You can't go anywhere near its limits on public roads, except in a straight line. If you want sideways fun, there's the MX-5 and BRZ/FR-S for exactly that.
In a more powerful car (trust me, 325HP is still a lot in a 2900lb car!), DCTs give you a nice quick immediate jolt from the power surging in almost immediately. It keeps a wonderful engine note (and boy does a Cayman S with sport exhaust make some noise) uninterrupted and always on boil. Once Porsche changes its PDK shift levers to those like the GT3 (pull to upshift), those who want to think they're in a racing car with a sequential box can. If I could get PDK-S in a Cayman S, I would and would mostly use the shift lever.
I find most detractors of a good DCT haven't driven a car with one. Additionally, not all manuals are great to begin with, which can be frustrating when you're trying to be quick. The MX-5 is ridiculously good for what the car cost. The Type 997 911 had a great 6-speed as well. My Lancer Evolution VIII MR had an extremely heavy clutch, and I'd say the last few BMW M cars have had a heavier clutch than I'd prefer (and dev money was mostly spent on DCTs). Corvette Z06s and Vipers (last drove a third gen/ZB) require a very deliberate use of the shift lever.
As for the Cayman S, it's a damn serious car. My load out hits 60 in 4.1-4.2s with launch control, and the 1/4 mile in around 12.6-12.7 @ 110mph (and 175mph in ~49 seconds). A set of Michelin Pilot Super Sports will get it to hold around 1.1g of lateral grip (sustained, not peak). You can't go anywhere near its limits on public roads, except in a straight line. If you want sideways fun, there's the MX-5 and BRZ/FR-S for exactly that.
In a more powerful car (trust me, 325HP is still a lot in a 2900lb car!), DCTs give you a nice quick immediate jolt from the power surging in almost immediately. It keeps a wonderful engine note (and boy does a Cayman S with sport exhaust make some noise) uninterrupted and always on boil. Once Porsche changes its PDK shift levers to those like the GT3 (pull to upshift), those who want to think they're in a racing car with a sequential box can. If I could get PDK-S in a Cayman S, I would and would mostly use the shift lever.
I find most detractors of a good DCT haven't driven a car with one. Additionally, not all manuals are great to begin with, which can be frustrating when you're trying to be quick. The MX-5 is ridiculously good for what the car cost. The Type 997 911 had a great 6-speed as well. My Lancer Evolution VIII MR had an extremely heavy clutch, and I'd say the last few BMW M cars have had a heavier clutch than I'd prefer (and dev money was mostly spent on DCTs). Corvette Z06s and Vipers (last drove a third gen/ZB) require a very deliberate use of the shift lever.
Thanks for the reply :) Hope it's a blast. The Cayman S is my #1 dream car. (I currently drive a Z4 3.0si coupe and take it up to Brainerd International once or twice a year.)
The cayman/s has very high limits that you wont reach on a public road. If you are driving it solely on public roads, the PDK is actually great. Its good in stop and go traffic, making that occasional/daily commute to the office much more pleasant.
I should point out that it doesn't matter how long it takes to downshift as long as you're in the right gear by the time you start turning.
> a dual clutch is not much faster than a properly-operated manually-clutched gearbox
That's not correct. When the GT-R first came out I read a great article about why it was so damn quick down the 1/4 compared to super cars that are 2-6x more expensive. The reasons were:
1. Most of them dyno at around 480hp AT THE WHEELS. So it's making more power than Nissan claims.
2. It's the first car to get all the electronics (stability control, etc. etc.) good enough to actually make it faster, not just get in the way
3. The dual-clutch gearbox changes were so fast, they did a comparison of how long the GT-R is in neutral during the 1/4 compared to other supercars with regular manual gearboxes. I remember the time difference being in the .4-.8 second range. That was the #1 reason it was so fast - it spends an extra 0.5 seconds actually putting power to the road, which is obviously huge in a ~12 sec 1/4.
That's not correct. When the GT-R first came out I read a great article about why it was so damn quick down the 1/4 compared to super cars that are 2-6x more expensive. The reasons were:
1. Most of them dyno at around 480hp AT THE WHEELS. So it's making more power than Nissan claims.
2. It's the first car to get all the electronics (stability control, etc. etc.) good enough to actually make it faster, not just get in the way
3. The dual-clutch gearbox changes were so fast, they did a comparison of how long the GT-R is in neutral during the 1/4 compared to other supercars with regular manual gearboxes. I remember the time difference being in the .4-.8 second range. That was the #1 reason it was so fast - it spends an extra 0.5 seconds actually putting power to the road, which is obviously huge in a ~12 sec 1/4.
I suspect that a big limitation in shift speed is often the angular mass of the crankshaft and flywheel - that energy has to go somewhere in an upshift, and doing that quickly on a typical car with wide gearing and a heavy flywheel puts an incredible amount of stress on things. Gear ratios cancel out in the real world, since with close ratios you're also shifting more often.
I would expect something like the GT-R to have much less crank/flywheel angular mass than the average car, as well as beefed up transmission components. Even so, IIRC they had to dial things back a bit because transmissions were blowing up.
DCTs get rid of the delay from matching the input and output shafts of a conventional manual. Very helpful, but not a cure-all. My car (automated manual, non-DCT) spends much more time matching the engine to the input shaft than the input to the output shaft.
I would expect something like the GT-R to have much less crank/flywheel angular mass than the average car, as well as beefed up transmission components. Even so, IIRC they had to dial things back a bit because transmissions were blowing up.
DCTs get rid of the delay from matching the input and output shafts of a conventional manual. Very helpful, but not a cure-all. My car (automated manual, non-DCT) spends much more time matching the engine to the input shaft than the input to the output shaft.
You seem to have ignored my "All other things the same" qualifier - that means you have to assume that power, weight (except for the difference between the gearboxes,) suspension, environment, tires, and everything else, is identical for the quoted part of my sentence to apply.
I don't see how your first two points are relevant to what I said, or your original post. You can love the GTR all you want, I don't mind, and I never claimed that there was anything wrong with it.
As for point 3, if you were to compare to a theoretical manual transmission GTR, that half a second of extra power would still only net you a couple tenths advantage, since acceleration and aerodynamic drag are nonlinear.
And I stand by my claim that a couple tenths on a 12 second quarter mile is 'not much faster.'
I don't see how your first two points are relevant to what I said, or your original post. You can love the GTR all you want, I don't mind, and I never claimed that there was anything wrong with it.
As for point 3, if you were to compare to a theoretical manual transmission GTR, that half a second of extra power would still only net you a couple tenths advantage, since acceleration and aerodynamic drag are nonlinear.
And I stand by my claim that a couple tenths on a 12 second quarter mile is 'not much faster.'
> I don't see how your first two points are relevant to what I said
They're not, I just wanted to include them for the curious.
> You can love the GTR all you want, I don't mind, and I never claimed that there was anything wrong with it.
It's an amazing car, but it's not like I have one or even want one.
>As for point 3, if you were to compare to a theoretical manual transmission GTR, that half a second of extra power would still only net you a couple tenths advantage, since acceleration and aerodynamic drag are nonlinear. And I stand by my claim that a couple tenths on a 12 second quarter mile is 'not much faster.'
You've never tried to build a 12 second car have you? A couple of tens is HUGE for a well behaved road car with a sound system, air conditioning and creature comforts. You could easily spend tens of thousands on a drag car in an attempt to get that. (I just looked it up, Motor Trend ran an 11.6, which is F-A-S-T)
They're not, I just wanted to include them for the curious.
> You can love the GTR all you want, I don't mind, and I never claimed that there was anything wrong with it.
It's an amazing car, but it's not like I have one or even want one.
>As for point 3, if you were to compare to a theoretical manual transmission GTR, that half a second of extra power would still only net you a couple tenths advantage, since acceleration and aerodynamic drag are nonlinear. And I stand by my claim that a couple tenths on a 12 second quarter mile is 'not much faster.'
You've never tried to build a 12 second car have you? A couple of tens is HUGE for a well behaved road car with a sound system, air conditioning and creature comforts. You could easily spend tens of thousands on a drag car in an attempt to get that. (I just looked it up, Motor Trend ran an 11.6, which is F-A-S-T)
> with a sound system, air conditioning and creature comforts
Reminds me of that episode with May saying something on the lines of "We're going at 400kmph... and we've got air-conditioning and radio". Now, that is serious engineering.
Reminds me of that episode with May saying something on the lines of "We're going at 400kmph... and we've got air-conditioning and radio". Now, that is serious engineering.
Since we're talking robo-manual transmissions, I think you guys would appreciate Koenigsegg's clever design. They use a wet clutch (as a brake) on the input shaft of their transaxle to quickly match the speed required by the next gear. End result is a lighter weight single clutch transaxle that shifts just as quickly as the DSG/PDK dual clutch designs. Let's just ignore the 1.5M price tag.
My parents' car has something like this (DSG). It takes forever between pressing the gas and actually moving forward. After that the car is fast and has power, it's just not fast to get going when you press the gas, you gotta anticipate. It's really very annoying and I much prefer a normal car, I really can't recommend it to anyone, but maybe it just takes getting used to.
I'm going to suggest that if you want to call yourself an engineer in any field, you should be able to quickly understand, among other things, how engines and air conditioning work. If not, there's always the management track ;) Good to see there are some other gearheads here.
A professor in college once told me that if you can't explain a technology, you might as well assume it's magic.
Cue the Arthur C. Clark quote:
“Any sufficiently advanced technology is indistinguishable
from magic.”That's Clarke's Third Law. I'm fond of the First Corollary to Clarke's First Law (allegedly first mentioned by Benford):
"Any technology which is distinguishable from magic is insufficiently advanced."
Can't edit my comment, and no one will care at this date, but...
s/First Law/Third Law/
Obviously the quote I posted is the corollary to the quote negativity posted. Derp derp derp.
s/First Law/Third Law/
Obviously the quote I posted is the corollary to the quote negativity posted. Derp derp derp.
I'm a Sagittarius and we're skeptical.
Isn't that how medicine works?
I agree. When I first started looking into medications like Aderall, it was surprising to find how little we actually know about how medicine works.
Take the above example - we really don't know how it works. We measure the amount of dopamine/serotonin in the spine before and after you take it so we assume it increases the presence of those chemicals in the brain, but it's not really mapped out.
A lot of people have the misconception that we understand the body the way we understand other technologies. That you can balance a chemical equation and deduce how something will effect the body.
While we understand a lot, this really isn't the case. And for all practical purposes it sometimes is treated like "magic".
Take the above example - we really don't know how it works. We measure the amount of dopamine/serotonin in the spine before and after you take it so we assume it increases the presence of those chemicals in the brain, but it's not really mapped out.
A lot of people have the misconception that we understand the body the way we understand other technologies. That you can balance a chemical equation and deduce how something will effect the body.
While we understand a lot, this really isn't the case. And for all practical purposes it sometimes is treated like "magic".
We even have a Ministry of Medical Magic in the US now: http://nccam.nih.gov
Thats really depressing.
You know what they call alternative medicine that works?
Medicine.
(cf: Tim Minchin, 'Storm' http://www.youtube.com/watch?v=HhGuXCuDb1U)
You know what they call alternative medicine that works?
Medicine.
(cf: Tim Minchin, 'Storm' http://www.youtube.com/watch?v=HhGuXCuDb1U)
The brain (and how it works) specifically is an area that modern medicine really hasn't figured out yet. I learned this when my father had a stroke. Talking to the doctors I learned that, unlike the rest of the body, our understanding of the brain is still sufficiently primitive that it's treated as sort of a black box.
Yes. As an example, you'd be surprised by how few MDs that are experts in their respective fields have a detailed understanding of the pharmacokinetics of the drug they're prescribing. They just take the dose the drug company did trials at and go with it.
One reason is that it takes a lot of modeling to understand why to dose 1x twice a week vs 2x once a week, so everyone gets roughly the same dose.
One reason is that it takes a lot of modeling to understand why to dose 1x twice a week vs 2x once a week, so everyone gets roughly the same dose.
that wasn't really very helpful or education of your professor. What, I wonder was, their point? I can't explain why the earth's core is still so damn hot after cooling for several billion years, but I know it's not magic. I could name you many areas that I'm not an expert in, but I know for a fact none of them rely on magic, except possible quantum mechanics. The jury's still out on that being magic.
The cooling of the earth and why the core is hot is actually a very interesting topic. Lord Kelvin (who has the temperature unit named after him) came up with an argument that the earth had to be 20 to 40 million years old if you assumed it started as a molten lump of rock and solved the equations for how long it would take to cool. (This age for the earth made both the evolutionists and creationists unhappy, by the way.)
He had a very clever argument, but the factor he was missing was radioactive decay, which provides an additional heat source. He also carefully figured that the Sun couldn't be more than 20 million years old, but here he was missing the existence of fusion as a power source.
He had a very clever argument, but the factor he was missing was radioactive decay, which provides an additional heat source. He also carefully figured that the Sun couldn't be more than 20 million years old, but here he was missing the existence of fusion as a power source.
For an old school look at internal combustion engines, check out this episode of The Secret Life of Machines:
http://www.youtube.com/watch?v=gfr3_AwuO9Y
The whole show is well worth the time.
http://www.youtube.com/watch?v=gfr3_AwuO9Y
The whole show is well worth the time.
The whole series was great. Worth watching for sure.
You guys are unreal with your comments - is it jealousy or something. Whatever it is it make me want to never come here again
Spot on.
Everything posted here is viewed as an opportunity for critique. It's driving me away as well. Perfect is truly the enemy of the good.
Truth be told, it was a few diagrams similar to these (though non-moving) that I saw and studied when I was probably about ten years old that fired up my interest in the mechanics of automobiles specifically. That turned into a long-term pursuit and I even spent several years working professionally as a mechanic and delving into some custom and high-performance work. It was doing engine performance management and working with ECUs that I dove into electrical signalling and decided to shift gears a little and get into the high-tech world, so I put myself through college at night. I still think of those diagrams from time to time.
Someone's creation of a few diagrams like this years ago opened up this kid's mind in a lasting way. I'm sure there were plenty of criticisms to be made on them, but they still had an important and lasting impact.
Everything posted here is viewed as an opportunity for critique. It's driving me away as well. Perfect is truly the enemy of the good.
Truth be told, it was a few diagrams similar to these (though non-moving) that I saw and studied when I was probably about ten years old that fired up my interest in the mechanics of automobiles specifically. That turned into a long-term pursuit and I even spent several years working professionally as a mechanic and delving into some custom and high-performance work. It was doing engine performance management and working with ECUs that I dove into electrical signalling and decided to shift gears a little and get into the high-tech world, so I put myself through college at night. I still think of those diagrams from time to time.
Someone's creation of a few diagrams like this years ago opened up this kid's mind in a lasting way. I'm sure there were plenty of criticisms to be made on them, but they still had an important and lasting impact.
Never underestimate the pedantry of a crowd of IT-types. I used to be like that, but I grew out of it.
The main problem seems to be that it's either a simplification - which is needed because the real thing is too complex to absorb at once - or the technology choice doesn't meet their expectations.
As someone who knows all about engines, I think it's neat. Too many people don't have the faintest idea about how their car works. Though I guess most don't care and it's my desire to know how everything works that makes me odd.
The main problem seems to be that it's either a simplification - which is needed because the real thing is too complex to absorb at once - or the technology choice doesn't meet their expectations.
As someone who knows all about engines, I think it's neat. Too many people don't have the faintest idea about how their car works. Though I guess most don't care and it's my desire to know how everything works that makes me odd.
I agree. People need to realise the market that this guy was targeting - it is average Joe on the streets, not the HN nerdy types. I know a fair amount engines and how they work, I still think it's very informative. The guy is a self taught graphic designer that judging by his portfolio works mainly with Photoshop. Instead of some people complaining about "it should be tech X or tech Y", maybe reach out to the guy and try to work with him.
I'd like to see one on airplane and jet engines next :)
I'd like to see one on airplane and jet engines next :)
this particular instance isn't the pedantry of IT-types, it's the pedantry of car-types.
every car forum / mailing list / meetup ever is full of this kind of one-upmanship.
every car forum / mailing list / meetup ever is full of this kind of one-upmanship.
I don't know what you're talking about, most comments look very positive to me.
I had a rather vague idea of these processes so it was great to see everything laid out simply.
As a Subaru driver, I was trying to picture how the cylinders in a flat/boxer engine are attached to the crankshaft: http://en.wikipedia.org/wiki/Flat_engine has a simple animation that shows it if anyone else is interested.
As a Subaru driver, I was trying to picture how the cylinders in a flat/boxer engine are attached to the crankshaft: http://en.wikipedia.org/wiki/Flat_engine has a simple animation that shows it if anyone else is interested.
How a gasoline car engine works, specifically a piston car engine with injection. There are lots of other variations on the theme of car engine. For instance, Diesel, Natural Gas, LPG, electricity (non-hybrid) and another configurations for the hot chamber, for instance a Wankel engine. Instead of injection there is carburation (an older, less efficient process for getting the fuel air mixture into the cylinders), and then there are turbo variations.
Of course gasoline, piston car engines are extremely common but the number of diesels can be very large depending on where you are (for instance, in Europe they are very common).
So for the general North-American view of what a car engine is this infographic is mostly correct but please don't take it as the be-all end-all of car engines, there is a lot more to it than that.
Of course gasoline, piston car engines are extremely common but the number of diesels can be very large depending on where you are (for instance, in Europe they are very common).
So for the general North-American view of what a car engine is this infographic is mostly correct but please don't take it as the be-all end-all of car engines, there is a lot more to it than that.
Indeed. It also assumes an overhead cam configuration, and ignores the possibility of a pushrod / lifter based cam/valve system. And showing a distributor glosses over the electronic timing systems that newer cars use, whereby they don't need a traditional distributor at all, just a crankshaft position sensor.
Still, for an engine neophyte, that was a pretty decent explanation.
Still, for an engine neophyte, that was a pretty decent explanation.
Even weedwackers have electronic ignition these days. That is why they are so easy to start. You don't have to fight the the preset advance.
Not to mention superchargers and turbo and supercharger combinations (AKA twinchargers). VW's 1.4TSI is a great twincharged engine:
http://en.wikipedia.org/wiki/Twincharger
http://en.wikipedia.org/wiki/Twincharger
Or Wankel engines: https://en.wikipedia.org/wiki/Wankel_engine
I was fascinated by the wankel geometry, and found other even more original shapes, unfortunately I forgot the name but that's close : http://www.youtube.com/results?search_query=engine+spherical
The analogical continuity of their surfaces and the discrete states of engines is very inspiring.
The analogical continuity of their surfaces and the discrete states of engines is very inspiring.
This is pretty cool. When I was younger I built a mini engine (from a kit[1], I wasn't fabbing components) which gave me a nice intro to the basics of how a car engine operates, but whilst parts of it are pretty simple to get it's helpful to see the process.
Even if it's a monolithic gif that annoys web developers. Or if it only shows one kind of engine design.
[1] http://www.scientificsonline.com/smithsonian-gas-engine-mode... is pretty close, but mine was a bit more basic. 15 years seems to have improved science kits a bit.
Even if it's a monolithic gif that annoys web developers. Or if it only shows one kind of engine design.
[1] http://www.scientificsonline.com/smithsonian-gas-engine-mode... is pretty close, but mine was a bit more basic. 15 years seems to have improved science kits a bit.
I had that same engine you link to as a kid except mine was orange instead of blue. It's definitely one of my more memorable childhood toys and even though a fairly basic representation of an engine, I agree that it was a great intro. On a side note, I remember the screwdriver that kit came with was ridiculously bad. It made stripping the included screws really easy and made putting together the model more of a chore than it should've been.
I always found this one video (http://youtu.be/K4JhruinbWc) on differentials enlightening.
Those old Handy organization films are incredible, here is my favorite but GM commissioned a lot of them.
http://www.youtube.com/watch?v=CCtJlgtZnBY
The US Army also has many very nice ones intended to introduce mechanics as well, there is one about power steering that is very good, but many more as well.
http://www.youtube.com/watch?v=AlpvyWAA8a0
http://www.youtube.com/watch?v=CCtJlgtZnBY
The US Army also has many very nice ones intended to introduce mechanics as well, there is one about power steering that is very good, but many more as well.
http://www.youtube.com/watch?v=AlpvyWAA8a0
Here's another one http://www.youtube.com/watch?v=mkQ2pXkYjRM : gears.
Water boil at exactly 100 degrees Celsius... not the conversion of 212 degrees Fahrenheit. Americans. ;-)
Nice job still.
Nice job still.
If you're going to take it that far you have to add "at standard pressure".
Also, I was under the impression that coolant does not boil at that high a temperature at standard pressure. The point of the sealed coolant system is to increase the pressure and hence the boiling point, but if it boiled at that temperature by default that would be unnecessary since no engine runs that hot.
Those are exactly the same, it's not an approximation. (212 - 32) / 9 * 5 = 100 exactly. Water boils at exactly 212 Fahrenheit under 1 atm pressure.
~95°C here (Denver, CO). Flatlanders. ;-)
> Water boil at exactly 100 degrees Celsius
Few people live exactly under 1 atm for any length of time.
Few people live exactly under 1 atm for any length of time.
Now here's a good website with nice animated illustrations. But it's all one giant animated GIF. It won't scale up or down and it's already running short on colors. This is something where WebGL would excel, you could get the full color palette and make it interactive. So far all WebGL demos I have seen are tech demos or simple games that look like OpenGL games did in 2004, and they have not been really used inside websites, only as a separate square.
Or SVG. But I don't want to take anything anyway from his effort - it's a wonderful work of art/education he's created.
Yes, SVG would work too but it is not ideal for 3d. The ability to rotate the view and zoom in to see the details would make this infographic even better.
I wish the 3d models that were used to draw this would be shared so I could try animating them in 3d.
And don't get me wrong, I think that this was an excellent inforgraphic.
I wish the 3d models that were used to draw this would be shared so I could try animating them in 3d.
And don't get me wrong, I think that this was an excellent inforgraphic.
Another benefit of not using a monolithic gif is the ability to translate the page to different languages. I could see a huge interest in non-English speaking countries for this.
If you find this sort of thing interesting, it might be fun to mess around with designing your own engine in Automation[1]. I've always been interested in cars, but playing around in this (currently in-development) simulation/game gave me a bunch of new insight into various engine parameters.
[1] http://www.automationgame.com
[1] http://www.automationgame.com
Since we've got a bunch of awesome gearheads commenting, can someone tell me why manual transmission is so easy to stall out? Particularly between say 1st and 2nd (although I'm sure it's got nothing to do with the actual gears). Just curious.
...aside from obvious commentary of my abilities driving manual ;)
...aside from obvious commentary of my abilities driving manual ;)
The only time I have stalled out is when I am pulling away in first and let the clutch come up to fast. If you are stalling your engine going from 1st to 2nd you are doing something wrong, since the wheels are moving at that point. Even if you let the clutch come up too fast the engine won't stall because the wheels will keep turning it. It might shudder and definitely not like the low RPM's, but it shouldn't stall.
With a manual all there is between the engine is the clutch and the transmission. When the clutch is engaged your engine to your wheels is a single straight line (with some gears in between, but lets ignore those for now). If your engine has a lot of power it will simply turn the wheels, however in most cases the engine is just simply not strong enough to break the friction of the tires agains the ground, especially in lower RPM's.
When you slowly let the clutch up, what you are doing is having the engine turn faster than the pipe connected to the wheels, by using some friction material you transfer SOME of the power from the engine to the pipe connected to the wheels, as you continue rolling eventually the pipe connected to the wheels catches up and spins at the same speed as the engine (once again, ignore gearing), at that point you can let the clutch up entirely (thereby basically connecting it directly).
When you go from first to second, you use RPM matching to have the engine spin at the same speed as the pipe on the other end. When the RPM's match, you let the clutch up and from there you can start providing more power by pushing the gas pedal.
See more about clutch construction here: http://en.wikipedia.org/wiki/Clutch
---
In most automatics there is a device called a torque converter that takes care of the friction part of the clutch for you. Interestingly enough it does this using fluid rather than friction material. There are fins on both sides of the torque converter, the two sides can freely spin. One side is connected to the engine, the other side is connected to the gear box. As you press the gas pedal, one side forces fluid through a series of fins, this whips the fluid into motion, this fluid is then forced through another series of fins on the other half. Because of the pressure difference in the fluid it will eventually have enough power to start forcing the other side (attached to the gear box and the wheels) to start moving. At some point the engine side is spinning just as fast as the wheel side, at that point most torque converters will actually lock. Now the torque convertor is directly connecting the engine to the transmission to the wheels.
When it switches gears, it disengages the torque converter lock, lowers the engine RPM's (even if you keep pressing the gas, it will use the computer to inject less gas temporarily), switch gears in the gear box, let the torque converter do it's thing, and once RPM's match closely re-engage the torque convertor lock.
See: http://en.wikipedia.org/wiki/Torque_converter
With a manual all there is between the engine is the clutch and the transmission. When the clutch is engaged your engine to your wheels is a single straight line (with some gears in between, but lets ignore those for now). If your engine has a lot of power it will simply turn the wheels, however in most cases the engine is just simply not strong enough to break the friction of the tires agains the ground, especially in lower RPM's.
When you slowly let the clutch up, what you are doing is having the engine turn faster than the pipe connected to the wheels, by using some friction material you transfer SOME of the power from the engine to the pipe connected to the wheels, as you continue rolling eventually the pipe connected to the wheels catches up and spins at the same speed as the engine (once again, ignore gearing), at that point you can let the clutch up entirely (thereby basically connecting it directly).
When you go from first to second, you use RPM matching to have the engine spin at the same speed as the pipe on the other end. When the RPM's match, you let the clutch up and from there you can start providing more power by pushing the gas pedal.
See more about clutch construction here: http://en.wikipedia.org/wiki/Clutch
---
In most automatics there is a device called a torque converter that takes care of the friction part of the clutch for you. Interestingly enough it does this using fluid rather than friction material. There are fins on both sides of the torque converter, the two sides can freely spin. One side is connected to the engine, the other side is connected to the gear box. As you press the gas pedal, one side forces fluid through a series of fins, this whips the fluid into motion, this fluid is then forced through another series of fins on the other half. Because of the pressure difference in the fluid it will eventually have enough power to start forcing the other side (attached to the gear box and the wheels) to start moving. At some point the engine side is spinning just as fast as the wheel side, at that point most torque converters will actually lock. Now the torque convertor is directly connecting the engine to the transmission to the wheels.
When it switches gears, it disengages the torque converter lock, lowers the engine RPM's (even if you keep pressing the gas, it will use the computer to inject less gas temporarily), switch gears in the gear box, let the torque converter do it's thing, and once RPM's match closely re-engage the torque convertor lock.
See: http://en.wikipedia.org/wiki/Torque_converter
Ack, yes, you're right, I meant starting up, rather than from 1st to 2nd. I've driven a manual exactly twice roughly 15 years ago when I was getting my license; it was more of an abstract question regarding engine workings than a specific question about how to avoid stalling :)
> Since we've got a bunch of awesome gearheads commenting, can someone tell me why manual transmission is so easy to stall out? Particularly between say 1st and 2nd (...)
It's not easy, only if use it wrong. It's easy to stall going from neutral to 1st if you don't apply enough gas (for instance, if you're on a slope, or the car is loaded), but it will only stall from 1st to 2nd if you're trying to do it from too low RPM (in this case the engine may take a while to stall completely, you can still avoid it by unclutching), or if you work the clutch too fast (the engine stalls right away).
It's not easy, only if use it wrong. It's easy to stall going from neutral to 1st if you don't apply enough gas (for instance, if you're on a slope, or the car is loaded), but it will only stall from 1st to 2nd if you're trying to do it from too low RPM (in this case the engine may take a while to stall completely, you can still avoid it by unclutching), or if you work the clutch too fast (the engine stalls right away).
You might look at what RPM you are shifting from 1->2. As the other poster said, 1->2 stalls are uncommon because the vehicle is in motion and the power from the forward inertia coming up the drive train into the engine is frequently enough to spin the motor, even if its shut off. However, if you upshift too soon, the engine with the 2nd gear ratios will be spun too slowly for the engine to pull itself out, and will instead drag the car to a stop.
I agree with the others, you might be shifting too early and so the RPM will be too low for 2nd. Did you have trouble at higher RPM to shift into 2nd, like the gear shift would not move it, so you started trying to do so sooner? If so it may be that you were trying to shift too quickly (the actual action of shifting). It's okay to push the clutch in, go into N briefly, and let the RPM drop a bit before shifting into second. So say you start the shift at 3500RPM, maybe let it drop to 2700, every car is different though. A mechanical explanation might be that your throw-out bearing is shot, but I think you would hear or feel it if it was that bad.
I loves this kind of graphical information.
If your more curious, here is a really old video with a really good explanation on differentials:
http://www.youtube.com/watch?v=F40ZBDAG8-o
http://www.youtube.com/watch?v=F40ZBDAG8-o
Some other cool configurations if anyone is interested.
Di Pietro http://www.youtube.com/watch?v=ZGiviT-C_oY
Rotary(wankel) http://www.youtube.com/watch?v=6BCgl2uumlI
Fibonacci Offset Rotary http://www.youtube.com/watch?v=tklMGxqRtw4
k-jetronic fuel system: http://www.youtube.com/watch?v=a4fJAfXYxWk
Di Pietro http://www.youtube.com/watch?v=ZGiviT-C_oY
Rotary(wankel) http://www.youtube.com/watch?v=6BCgl2uumlI
Fibonacci Offset Rotary http://www.youtube.com/watch?v=tklMGxqRtw4
k-jetronic fuel system: http://www.youtube.com/watch?v=a4fJAfXYxWk
This is an awesome infographic. One of the most used books in our home school curriculum was "The Way Things Work" which, for the most part, covered pretty much all of the things that we needed it to. We also took apart a few things to get a more 'hands on' appreciation of the mechanics.
For engines though, the "Suck, Squash, Bang, Blow" mantra used in the Secret Life of Machines was perhaps the most durable for my kids.
For engines though, the "Suck, Squash, Bang, Blow" mantra used in the Secret Life of Machines was perhaps the most durable for my kids.
suck squeeze bang blow
http://en.wikipedia.org/wiki/Four-stroke_engine
Mirror here: http://visual.ly/how-car-engine-works-animated
93 octane is premium fuel in the US? Petrol in the UK starts at 95 and premium is 98. What’s the practical difference then?
There are two measurements that can be made; RON (Research Octane Number, measuring fuel behavior at 600rpm) and MON (Motor Octane Number, measuring fuel behavior at 900rpm).
MON is typically 8-10 points lower than the RON.
In the US/Canada and some other parts of the Americas, they use the average of the two. Hence lower.
In most other places, they just use the RON.
http://en.wikipedia.org/wiki/Octane_rating#Measurement_metho...
MON is typically 8-10 points lower than the RON.
In the US/Canada and some other parts of the Americas, they use the average of the two. Hence lower.
In most other places, they just use the RON.
http://en.wikipedia.org/wiki/Octane_rating#Measurement_metho...
Octane is the US is the average of MON and RON as stated in the other reply, which usually places it about 5 point below the RON number which is used in Europe and many other places. Also, in higher altitudes you don't need as high an octane, so where I live (4000ft-9000ft) premium is 91.
My car asks for 91 octane fuel. I have no idea where I'm supposed to get that when all I see is 87, 89, and 93. Since it's an Italian-designed car, I was expecting that 91 is a common European designation. Perhaps not?
It's generally an 'at least', you probably don't need to worry about 93.
If it is modern and fuel injected, 89 or 87 will probably also be fine, it just won't perform quite as well (but the computer will notice and back off of the timing).
If it is modern and fuel injected, 89 or 87 will probably also be fine, it just won't perform quite as well (but the computer will notice and back off of the timing).
Yeah, I put in 93 once and had a small but noticeable increase in power. From my understanding, this only really happens if your knock sensor is retarding your timing with 87 octane and 93 lets it advance the timing further. It's 87 minimum, 91 recommended with my engine.
Since I secretly wish my car was a small diesel, the slight lack of power with 87 doesn't bother me too much :)
Since I secretly wish my car was a small diesel, the slight lack of power with 87 doesn't bother me too much :)
Now that the price difference between 87 and 93 is typically under 10%, using 93 may actually improve your gas mileage enough to make up for the difference in price. If your drive enough that fuel expenses are meaningful, it may be worth testing if this is the case for your car.
This will only work if your engine can achieve high enough compression to take advantage of the higher octane number. Many engines can't.
But if the engine is running on lower power because of the knock sensor, higher octane should be called for, right?
Yes, because that means the knock sensor is reducing compression because it senses lower octane gasoline.
Another note I've learned on higher octane gas: in areas prone to freezing temperatures (I live in the northern Midwest), 87 octane will, during winter, have ethanol added into the mix as an anti-freeze. This is commonly called the "winter blend", and is federally regulated to only be on the market during certain times. The ethanol has lower energy density than gasoline, and can hurt your mileage. Higher octane gas does not have extra ethanol added in. So there's a benefit to using midgrade or premium in cold weather.
It replaced MTBE as an oxygenate. It's present in some blends all the time.
Compression is fixed by the engine design. The only thing the ECU can do as a result of knock sensor input is retard ignition and close the throttle (and, on a turbocharged engine, lower charge pressure).
Retarded ignition does result in lowered gas mileage, but throttling down does not. It just decreases your maximum available power.
Plus, if you notice the decrease in power, your driving is not suitable for comparing gas mileage... ;-)
Retarded ignition does result in lowered gas mileage, but throttling down does not. It just decreases your maximum available power.
Plus, if you notice the decrease in power, your driving is not suitable for comparing gas mileage... ;-)
Compression is fixed by the engine design
The maximum possible compression is, yes, since it is determined by the size of the cylinders and the piston stroke.
But retarding the timing amounts to reducing the effective compression--basically you are wasting some of the compression that's available by delaying the spark until the cylinder has started expanding again. I should have made it clear that it was effective compression that I was talking about.
The maximum possible compression is, yes, since it is determined by the size of the cylinders and the piston stroke.
But retarding the timing amounts to reducing the effective compression--basically you are wasting some of the compression that's available by delaying the spark until the cylinder has started expanding again. I should have made it clear that it was effective compression that I was talking about.
Omg I can't believe they omitted the V-4!
This is a fun video about ignition order: http://youtu.be/MwEbwKBic6w (though it's more complicated since there are both 180 and 360 degree-firing V4s).
This is a fun video about ignition order: http://youtu.be/MwEbwKBic6w (though it's more complicated since there are both 180 and 360 degree-firing V4s).
It also left out the inline-6 (different from the flat-6) and the wankel. Here's a couple more piston configurations:
http://en.wikipedia.org/wiki/Category:Piston_engine_configur...
http://www.caranddriver.com/features/the-physics-of-engine-c...
Another fun subject is harmonic vibration and balance. Certain configurations require things like balance shafts and harmonic balancers (arguably unnecessary fluff) to offset the intense vibration, and modifying your engine can result in it self-destructing if this isn't taken into account. Inline and flat 6's and 12's are the best balanced, though the inline is more efficient and requires less maintenance than the flat.
http://en.wikipedia.org/wiki/V6_engine#Balance_and_smoothnes...
http://www.physicsforums.com/showthread.php?t=509340
http://en.wikipedia.org/wiki/Category:Piston_engine_configur...
http://www.caranddriver.com/features/the-physics-of-engine-c...
Another fun subject is harmonic vibration and balance. Certain configurations require things like balance shafts and harmonic balancers (arguably unnecessary fluff) to offset the intense vibration, and modifying your engine can result in it self-destructing if this isn't taken into account. Inline and flat 6's and 12's are the best balanced, though the inline is more efficient and requires less maintenance than the flat.
http://en.wikipedia.org/wiki/V6_engine#Balance_and_smoothnes...
http://www.physicsforums.com/showthread.php?t=509340
other notable omission are: the 2 stroke engine (commonly found in 2 wheel urban vehicle now these days) and the Miller cycle that was used in the Mazda Xedos 9.
Carbibles has great explanations of most car systmes with really nice animations. Here is the engine part:
http://www.carbibles.com/fuel_engine_bible.html
http://www.carbibles.com/fuel_engine_bible.html
Love engines!
Just put 500 break-in-miles on a recent VW Boxer "Shortblock" Rebuild I did this summer!
This one is an early Bosch Fuel Injection(DigiFant), almost like sensor-assisted carburetor.. it's funky. Totally "hackable"..
Just put 500 break-in-miles on a recent VW Boxer "Shortblock" Rebuild I did this summer!
This one is an early Bosch Fuel Injection(DigiFant), almost like sensor-assisted carburetor.. it's funky. Totally "hackable"..
this is really cool. would love to see one breaking-down wankel engines as well.
though i'm not technical by any means, i've always sort of got the high-level around how reciprocating/piston-based engines function. wankel engines seem a lot more efficient in terms of design but also weirdly complex. still kind of a mystery to me as to how they work and unfortunately there aren't too many cars around these days that run on em to check out..
though i'm not technical by any means, i've always sort of got the high-level around how reciprocating/piston-based engines function. wankel engines seem a lot more efficient in terms of design but also weirdly complex. still kind of a mystery to me as to how they work and unfortunately there aren't too many cars around these days that run on em to check out..
The underlying math: http://en.wikipedia.org/wiki/Otto_cycle.
This is a great illustration that demonstrates why gasoline engines NEED to die and be replaced by better, more efficient engines.
The problem isn't the efficiency of the engine, but the efficiency of storing energy. Gasoline and diesel are very good at that, and are easily replenished. If your concern is the complexity of all the moving parts, rotary engines and 2-stroke engines are significantly simpler, but ultimately 4 stroke reciprocating engines make more sense.
Especially the following quote about halfway down in the infographic:
"Engines get hot - the cooling system of a car going down the freeway dissipates enough heat to keep two average-sized homes warm!"
Think about that for a while. ICE's just have a thermal efficiency of about 30%, the rest becomes heat.
"Engines get hot - the cooling system of a car going down the freeway dissipates enough heat to keep two average-sized homes warm!"
Think about that for a while. ICE's just have a thermal efficiency of about 30%, the rest becomes heat.
Thank you very much! I'm trying to get better at understanding how cars work and this presentation helps immensely.
Air != oxygen. Only 20% of air is oxygen.
If the air to fuel ratio is 10, then the oxygen to fuel ratio is only 2.
If the air to fuel ratio is 10, then the oxygen to fuel ratio is only 2.
Nowadays hybrids are smarter. Combustion engine is used to charge batteries and provide power to the electric motor, it's more efficient way of using energy from gasoline. Using combustion with electric motor stands out to be much less efficient.
AFAIK we're still not doing it right. The best way is to make the electric motor the main motor, and having the gasoline engine be small and tuned to run at a consistent peak efficiency RPM, and only used to charge the batteries. This was figured out in 1979! http://www.motherearthnews.com/green-transportation/electric... (see the diagram in the fourth image).
Yes, that is exactly what I meant. There are already some cars that do it almost properly.
http://www.fiskerautomotive.com/ https://en.wikipedia.org/wiki/Yo-Mobile
Btw Yo-Mobile is interesting since they are using rotary engine to do power generation.
http://www.fiskerautomotive.com/ https://en.wikipedia.org/wiki/Yo-Mobile
Btw Yo-Mobile is interesting since they are using rotary engine to do power generation.
Thanks for the fisker link. I saw one on the road the other day but forgot to look it up later. They are as pretty as Teslas.
That isn't true, most hybrids still have a mechanical connection between the combustion engine and the drive wheels. That is, the Prius, Ford hybrids, GM hybrids, I'm sure others.
AFAIK, the Chevrolet Volt (and Opel clone, etc) is the only one where the engine just charges the batteries, and the drive wheels are run by the electric motor alone.
From a technical standpoint, it's a good design for a hybrid - you can optimize each part of the system separately. But GM didn't quite get the car as a whole correct -- it has some ergonomic problems, priced higher than the value (perceived and actual) the customer got, and so on.
From a technical standpoint, it's a good design for a hybrid - you can optimize each part of the system separately. But GM didn't quite get the car as a whole correct -- it has some ergonomic problems, priced higher than the value (perceived and actual) the customer got, and so on.
I actually checked before my comment. This article states that the combustion engine participates above 70 mph:
http://gm-volt.com/2010/10/11/motor-trend-explains-the-volts...
Maybe later models altered that arrangement.
http://gm-volt.com/2010/10/11/motor-trend-explains-the-volts...
Maybe later models altered that arrangement.
^ - this. Volt fires up gas motor to optimum efficiency point to serve as a generator for the electric motor, which is the only motor connected to the drivetrain
>the electric motor… is the only motor connected to the drivetrain
This is a common misconception. The Volt will drive the wheels directly from the gasoline engine when driving at high speed (>70 mph).
http://blogs.cars.com/kickingtires/2010/10/the-great-chevy-v...
This is a common misconception. The Volt will drive the wheels directly from the gasoline engine when driving at high speed (>70 mph).
http://blogs.cars.com/kickingtires/2010/10/the-great-chevy-v...
Agree, Prius and others aren't actually efficient in terms of fuel usage. And they aren't "green".
They're more efficient than the same sized non hybrid car. And define "green"
It's not about what engine size do you have, it's all about engine efficiency and how you drive. Small car can be efficient without any fancy hybrid technologies, big engine can be efficient with smart engineering.
Love it, best thing on HN today! Could you add diesel and 2 stroke?
Don't forget the Wankel (rotary) engine! Few people have even heard of them, and even fewer have any idea what they are or how they work. I love my dorito on a stick.
Down the street from where I lived in Stuttgart someone owned a NSU Ro 80.
I also remember seeing a few Mazda rotary pickups in my early years in the US - very cool but apparently not very reliable and very inefficient.
I also remember seeing a few Mazda rotary pickups in my early years in the US - very cool but apparently not very reliable and very inefficient.
Relevant visual reference: http://www.animatedengines.com/wankel.html
http://www.animatedengines.com/index.html
Even steam engines.
Even steam engines.
I always loved how internal combustion engines can be summed up into 4 words: Suck, Squeeze, Bang, Blow.
Of course that means intake, compression, combustion and exhaustion :)
Awesome. Would be cool to add the W engine configuration as well.
That would probably just serve to confuse people, as it's essentially two VR* engines grafted together. The VR6 is, while more common than the W's, still fairly obscure even within the VAG line of autos, and certainly outside of it.
So, yes, they're cool machines, but probably not a whole lot of utility in this context as they work the same way, but in a funky shape :)
So, yes, they're cool machines, but probably not a whole lot of utility in this context as they work the same way, but in a funky shape :)
Compressed air car engine would be interesting https://en.wikipedia.org/wiki/Air_car
I love this video for explaining how steering works.
https://www.youtube.com/watch?v=yYAw79386WI
https://www.youtube.com/watch?v=yYAw79386WI
Well I finally know what octane means.
Am I the only one who sees all that complexity and yearns for a Tesla? (3 moving parts.)
Which is the same number of moving parts as a basic two stroke engine.
The trouble is the damn heavy and slow to charge batteries plus of course the environmental efects of mining all the battery materials.
What we need is a fuel cell based car with electric drive.
The trouble is the damn heavy and slow to charge batteries plus of course the environmental efects of mining all the battery materials.
What we need is a fuel cell based car with electric drive.
Great illustration. Thanks!
Finally I can learn how a car works and become a real man, thanks!
Is anyone else getting a 403 error? I think HN crashed his site.
I am now more useful in a post-apocalyptic world. Awesome!
Loved it! Had actually no idea how a car engine worked.
Now, if software was that modular... Sigh...
Not MY engine.
Rotary :D
Rotary :D
One day, when the sun is shining and the birds are happily chirping away in the trees, someone is going to submit a similar headline. "How X works", with X being something interesting. "How slowing down your metabolism with paint thinner works" or something.
I'll click on the article link, like I usually do and one day the article will be just one sentence.
"Well"
I'll click on the article link, like I usually do and one day the article will be just one sentence.
"Well"
Until the early 2000s most fuel injected gasoline engines were multi-point injection - the fuel was injected in to the incoming air stream immediately before the cylinder, and before that indirect injection which injected where the carburettor was.
Then there are carburettor engines.
Most diesel engines have been direct injection for many decades now, due to the behaviour of the fuel.