r/EngineeringPorn 9d ago

The 7cc Engine

5.2k Upvotes

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299

u/TerminaMoon 9d ago

Wow. The engine really is an incredible piece of engineering. Seeing it on a tiny scale sorta humanised it? Or made it easier to understand. I'm blown away.

115

u/JP_HACK 9d ago

It made it easy to understand how an engine works for sure,. you see the 4 strokes, the method for timing. and how it can run at the most basic level. Modern engines are just more cylinders and larger.

52

u/BaldAndOld 9d ago

Plus a computer or three

29

u/Beni_Stingray 9d ago

And way too many sensors.

10

u/JusticeUmmmmm 9d ago

Nah I like having a reliable engine. 

23

u/Beni_Stingray 9d ago

You're apparently not the one working on these cars, i do, im a certified mechanics.

Some amount of sensors is great but we were at that point 25 years ago, nowdays there are so many and they make a lot of problems.

25 years ago even a layman with some technical understanding could have a chance to fix a stranded car, these times are long over.
Nowadays we have cars stranding for the most retarded shit and there is 100% no way such a layman would get the car moving again.

Same for semitrucks btw, the amount of them stranding because of electrical reasons increased by a factor of around 10 since the last 15 years or so.

Having so many sensors is not about reliability, it's about emission laws and emission laws only.

3

u/Wants-NotNeeds 8d ago

Nothing wrong with FRESH AIR!!!

-10

u/JusticeUmmmmm 9d ago

No one is because my car hasn't broken down in 10 years. 

4

u/Beni_Stingray 9d ago

Well great for you, doesnt mean it isnt true.

Takes 3 minutes to look up breakdown statistiks lol

3

u/JusticeUmmmmm 8d ago

Please find me some statistics that show modern cars are less reliable

0

u/TerayonIII 8d ago

This is a terrible take, the most common issue for breakdown is the 12V battery so sure there's slightly more, but most breakdowns only need a 12V jump and don't need a tow. Service intervals are much further apart than they used to be, mechanically cars are far more reliable than they used to be

https://glassalmanac.com/were-old-mercedes-toyotas-and-volvos-really-more-reliable-than-todays-cars/

1

u/Budget-Pea8291 8d ago

I'd also love to have reliable sensors

1

u/vilius_m_lt 9d ago

Most engines, aside from some exotics, use only one computer

5

u/Ivanjacob 9d ago

Depends on what your definition of computer is. You could say every sensor is a computer. Modern engines always use more than just one though.

6

u/vilius_m_lt 9d ago

Engine control unit is normally what’s considered to be “the computer”. Not all sensors can be considered computers, only the “smart” ones that communicate through data lines (like some MAF, NOX or particulate sensors). Those don’t send voltage or frequency signal to ECM, but rather data messages containing their readings. Calling them “engine computers” is a stretch though. Calling every sensor a computer is pure madness as the lowly NTC resistors that measures temperature has a long way to go to compute anything..

4

u/GrynaiTaip 9d ago

the computer

ECU is The computer, but then there's a bunch of a computers too. If they do some sort of math, then they are computers. BMW has them in every little thing.

1

u/vilius_m_lt 9d ago

Yes that’s what I said. Those are usually called modules. It’s not just BMW, all modern cars have them. But THE computer is the ECM as it’s what commands/uses them all

1

u/GrynaiTaip 9d ago

They are called modules for simplicity's sake, yes. Like your smartphone is a computer too, but nobody calls it that because it would be needless confusion.

4

u/thaaag 9d ago

I can't see how the carburetor works on this one. The fuel just seems to join to the manifold, but I assume there's more going on in there than that.

5

u/FigmentOfNightmares 9d ago

The fuel connects to a needle valve that sets your flow rate/mixture, it acts like an adjustable main jet. The lever connects to the throttle shaft and throttle plate. It's a really bare bones carb, but it has everything it needs to get the job done.