
How a Car Engine Works - kercker
http://animagraffs.com/how-a-car-engine-works/
======
delbel
I'm changing my career slightly from full stack development to repairing and
restoring old tractors and farming. I have a 1952 Case SC, a 1957 Fordson
Major, and a 1946 Ford 2N in various conditions. I'm building a shop to work
on them. Basically its an excuse to buy a sand blaster and paint room. Buy
them for $500 and sell them for $3500 restored, pay for the tools and the next
project tractor. Hopefully picking up a 1970 Ford 3600 this week. Old Diesels
fascinate me.

~~~
ndespres
I'm halfway through a similar transition to farming. It's funny how sometimes
a new task can be an excuse to buy more tools. I'd be interested in reading
more from you about your new work!

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WalterBright
I learned how they worked by taking one apart, putting it back together, and
got it to run (it was a junkyard car). My auto shop teacher told me he was
amazed, because I was a nerd and nerds had no mechanical aptitude.

~~~
tostitos1979
Did you take a class in high school? Wish there was a place for adults to
learn without a full fledged college course or certificate program.

~~~
bcook
Get a VW Bug or an ATV with an air-cooled, four-stroke engine. Buy a good
torque-wrench, a socket set, some allen wrenches, and a proper
disassembly/reassembly manual and get to work!

I have removed every rolling part of my ATV. It's quite strange to go 65MPH
knowing that you put all the parts together... I am still alive so far, ha. :)

~~~
tostitos1979
Last few cars I've owned seem to be designed to prevent the owner from even
looking under the hood. They don't seem to design them for easy user access
anymore. But then again, I came across a computer from ASUS the other day that
said you void the warranty if you open up your case. WTF???

~~~
Scoundreller
On the plus side, you have far more to work with these days than a Haynes
manual. You'll have Youtube videos, discussion forum posts on every job,
'borrow a tool' programs from stores/libraries, a range of parts-suppliers
competing for your dollars that will ship to your door...

~~~
zachrose
Indeed. After looking in the right places I was able to get the 300-page shop
manual for my motorcycle. Everything is very well diagramed and OEM parts are
readily available online for not much money.

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bcook
In my limited experience, OEM is __horrible __, unless it is the only option.

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kw71
This is funny because there is a brand called "OEM" at parts stores that sells
chinese junk.

I am all about finding the original parts that the dealer will sell, but on
the aftermarket at reasonable prices.

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semi-extrinsic
The animations are nice, but it wouldn't hurt to step up the level of detail:
there's no mention of ECU, MAF sensor, lambda sensors, injector pulse
duration, throttle body, crankshaft sensor, flywheel, turbocharging,
connection to accelerator pedal, etc..

But the most annoying detail is showing a distributor on a fuel injected
engine. Come on, this isn't 1986, at least show us a dual coil pack wasted
spark system.

~~~
mikestew
That's nice and all, but until one understands the four stroke cycle, the rest
of what you mention is noise. Suck, squeeze, bang, blow: until you know that,
knowing what a lambda sensor is just uses up space that could be used learning
Rust instead.

I mean, get real, anyone capable of understanding injector dwell is probably
not clicking that link. It's not for the likes of you and me. What's next, go
leave comments on the "Idiot's Guide to How Computers Work" about how it's not
complete if they don't explain pointers?

~~~
semi-extrinsic
My biggest gripe is not including the link to the accelerator pedal. If you
don't know how pushing the pedal makes the engine spin faster, do you even
have a basic understanding of how engines work?

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mikestew
Yeah, I'll give you that one. I think it does open a can of complexity,
though, what with explaining intake vacuum and all. OTOH, it would solve the
mystery for those that know what the accelerator cable attaches to, but have
no idea how opening a plate makes "vroom vroom" noises.

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andrewdb
The timing chain and the camshaft seems really inefficient; I'm looking
forward to when camless designs become more mainstream. Koenigsegg (among
others, I assume) has been working on this tech [0][1].

0: [http://blog.caranddriver.com/koenigseggs-camshaft-less-
engin...](http://blog.caranddriver.com/koenigseggs-camshaft-less-engine-
explained-watch-it-in-action-video/)

1: [https://youtu.be/Bch5B23_pu0](https://youtu.be/Bch5B23_pu0)

~~~
Grishnakh
It _is_ really inefficient. A lot of energy is wasted compressing the valve
springs to open the valves. This is a problem if you try to make a high-
revving engine, for instance, in order to get better fuel efficiency at low
speeds and good power at high rpms: to allow high-rpm operation, you need
stiffer valve springs, but this significantly affects your fuel economy.

They've been working on camless valve actuation for decades. I read an article
about a prototype system back in 1992. The article then said that the power
requirements of the solenoids was a big problem. I'm not sure what the problem
is these days. As you noted, Koenigsegg has a working prototype in an actual
car (not on a test stand, connected to mains power, like the one in the
article in 1992), and it seems to work fine. There's probably some kind of
problems with reliability.

~~~
userbinator
_This is a problem if you try to make a high-revving engine, for instance, in
order to get better fuel efficiency at low speeds and good power at high rpms:
to allow high-rpm operation, you need stiffer valve springs, but this
significantly affects your fuel economy._

The alternative is to just not design for high RPM; the most efficient
internal combustion engines are huge low-speed two-stroke diesels used for
ships and stationary generators.

~~~
extrapickles
Large marine diesels have very low RPM. Some of them red-line at 102 RPM, and
normally operate much less than that. A typical passenger cars idles at
1200RPM and redlines around 6-7K RPM.

Then again a single piston in the marine engine weighs 2x of an entire car so
they can easily do things that one wouldn't bother to do on a smaller engine.

~~~
Grishnakh
>A typical passenger cars idles at 1200RPM

No, they don't. 750rpm is pretty typical these days. They'll idle at higher
speeds when cold, though, to warm up faster.

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Animats
The Cartoon Network version.[1] Not bad, actually.

And, inevitably, the Jam Handy / Chevrolet film on engines.[2] There's a whole
series of these, with ones for suspensions, transmissions, differentials,
lubrication, and frames.

[1]
[https://www.youtube.com/watch?v=IQj00NTFXew](https://www.youtube.com/watch?v=IQj00NTFXew)

[2]
[https://www.youtube.com/watch?v=fKbSloJ5o7o](https://www.youtube.com/watch?v=fKbSloJ5o7o)

~~~
dsfyu404ed
Those videos aged really, really well (the 1930s ones)

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ju-st
If you like designing engines and cars then look at this game
[http://store.steampowered.com/app/293760](http://store.steampowered.com/app/293760)

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infocollector
What software do they use to make these animations? Does anyone know?

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aitolajau
Blender, Flash professional, Photoshop and Illustrator.
[https://www.behance.net/gallery/10749619/How-A-Car-Engine-
Wo...](https://www.behance.net/gallery/10749619/How-A-Car-Engine-
Works-\(animated-infographic\))

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RKearney
Previous Discussion:
[https://news.ycombinator.com/item?id=6332385](https://news.ycombinator.com/item?id=6332385)

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kevindeasis
Most of my guy friends really like cars. They know good amounts about
different parts of the cars.

I've never enjoyed reading about them. So, I've never tried learning much
about them. It also takes alot of time.

I wish there were more of these type of animated illustration. I've scanned it
for a few minutes and I grasped the concept it was trying to show me
relatively faster than anything I've ever encountered.

~~~
calsy
Theres a whole site full of them if you click the title.

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tmptmp
I have a question: exactly what causes the piston to come back after the
intake/power stroke? Let me write what I guess I have understood -

1\. The intake stroke piston movement may be considered to be caused by
gravity and/or atmospheric pressure

2\. The power stroke piston movement may be considered to be caused by gravity
and/or atmospheric pressure and/or the expansion due to explosion all taken
together

Correct me if I am wrong.

But what baffles me is this: what causes the piston movement during the
compression stroke and exhaust stroke? Any expert here to enlighten me on
this?

edit: typo

~~~
delinka
If you can find a pull-start gas engine lawn mower, you can learn lots from
it. These things generally have a single piston. The pull string that you use
to start it gets it moving in the right direction, and once it starts running
on its own, it's momentum that brings it back around for another go.

Also keep in mind that this single piston engine is _two-stroke_ and not four
as in the article.

Back to four stroke engines: Momentum and the firing of other pistons keeps
the whole thing cycling back around. The more pistons you have, the more there
are firing between each revolution of a given piston (and thus overcoming
resistance and supplementing that momentum) and thus the more power available
to drive the vehicle.

~~~
dbloom
This is a great explanation. I'd add one small clarification:

> Back to four stroke engines: Momentum and the firing of other pistons keeps
> the whole thing cycling back around

The firing of other pistons helps, but really, momentum alone is sufficient.
There are tons of single-cylinder, 4 stroke motorcycle, scooter, and off-
highway engines out there.

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capote
Wow! What a straightforwardly cool and enriching post. I've had a vague idea
of how engines work (as well as turbochargers) but somehow I've never bothered
to get it straight.

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ericjang
Does anyone know what software was used to render the animations? His
interview with Adobe suggests that he makes 3D models in Blender, but I'm not
sure about the renderer.

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ankit84
How a gun works is also an amazing piece of artwork:
[http://animagraffs.com/how-a-handgun-
works-1911-45/](http://animagraffs.com/how-a-handgun-works-1911-45/)

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m0rganic
Single piston engine technology looks pretty promising as it has proven to be
30% more efficient than 4 piston combustible engine.

[https://youtu.be/JoQkTIfAB2U](https://youtu.be/JoQkTIfAB2U)

~~~
jjoonathan
Doesn't TFA say that opposed pistons were used in the classic VW bug ("Flat
Four"), suggesting there's a good reason they aren't used elsewhere?

~~~
Grishnakh
As the other poster said, they have advantages and disadvantages. Subarus and
Posches use them (though in the Porsches, they're flat-6 engines, not flat-4).

The big advantage is center of gravity: their shape lets them sit basically
flat, near the ground, and since engines are the heaviest part of a car, this
gives the car a lower center of gravity, which is good for handling.

The main disadvantage is mechanical complexity: instead of all the cylinders
lined up in a row, with the crankshaft on one side and the valves and dual
cams on the other, you have two banks of pistons, each with their own
camshafts. So now instead of two camshafts, two camshaft gears, and one timing
belt/chain, you need double all those. This of course increases cost too.

Flat-fours also tend to have rather distinctive exhaust notes, which not
everyone finds pleasing.

Another notable place flat-4 engines are used is in small aircraft. Lycoming
and Continental engines for small (e.g. Cessna) airplanes and helicopters are
all flat-4.

~~~
brc
Porsche now makes a flat 4 engine again- the new Boxster/Cayman engines are
turbo 4.

On the cost issue, Porsche famously tried to cut costs for the 996/Boxster gen
1 by using a common cylinder head casting for both sides. This was done by
flipping it over for the other side. The only problem with this was providing
the drive for the camshaft from the rear of the engine. To do this, they
created an intermediate shaft operating at the rear of the engine. This worked
ok but it couldn't have an oil fed bearing, so they used a roller bearing.
This caused a failure rate if something like 5% of engines, and caused a class
action suit that Porsche had to settle.

The other advantage of boxer engines is their suitability for air cooling and
packaging. In fact, Porsche produced an aircraft version of the flat 6 but it
ended up being too exprensive to build and run, despite outperforming a
lycoming by a long way.

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electriclove
I like the animation on this site:
[http://auto.howstuffworks.com/engine1.htm](http://auto.howstuffworks.com/engine1.htm)

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carsongross
It may be karma-bait, but it's very nice looking karma-bait.

OTOH, no inline six, which is the platonic ideal of the ICE.

As such, I can't up vote this.

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vvanders
No rotary either!

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nimasmi
My previous car was a Mazda RX-8, and my current car is a Nissan LEAF. I feel
under-represented.

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jedanbik
Watercooling on an enthusiast/gaming PC and a car's radiator + waterpump
definitely has its similarities.

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intrasight
When I click and drag the mouse, it doesn't rotate or zoom the model. Am I
using it wrong? ;)

~~~
calsy
Yes.

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gnarbarian
Suck, squish, bang, blow.

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known
Brilliant post;

~~~
rxm
Second that. We should thank Jake for all those amazing Animagraffs on his
site. Those are a lot of work to produce.

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maerF0x0
It was only worth a few points each time its submitted. If you're going to
post something a few years old, then put the date in the title.

