In-cylinder video footage

[Steam]

This is quite interesting, I wonder how they did it?
For those of you without broadband it is a slow motion video of a piston cycle. Nothing we didn't know, but interesting to see.
If anyone else knows of similar videos, please post them.

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[Devil]

Thats pretty darn cool.

[TLMAN]

Dumb ass question time?

Why does one side open then the other in alternate?

[Marmoot]

So that both are not openning at the same time?

[idb]

Dumb ass question time?

Why does one side open then the other in alternate?

One side let's the fuel in, the other side lets the exhaust out.

[vifferman]

Actually, in the real world they ARE both open at times - it's called valve overlap, and is used to get maximum cylinder filling. The exhaust gases going out helps pull the intake charge in.

[Steam]

Actually, in the real world they ARE both open at times .

What does this lead you to believe about the video? Old-school engine?

[idb]

What does this lead you to believe about the video? Old-school engine?

Maybe a demo only.
Just to show the principle of four stroke engines.

[Dargor]

I like these illustrations from wikipedia.

http://en.wikipedia.org/wiki/Two-stroke_engine
http://en.wikipedia.org/wiki/Four-stroke_cycle

[twinkle]

another question, the intake valve looks like it opens a little just before the spark, whats going on there?

edit: nope, it doesn't, just some vapour.

[ManDownUnder]

The video is edited as you don't see the exhaust valve close (it goes from a fully open position to instantly shut). Slightly before, or slightly after - depending on the set up- the time of exhaust valve closure you would see the inlet valve opening too. Valve overlap as someone already mentioned.

Think of the 4 storked as follows:
Suck (intake)
Squeeze (compression)
Bang (ignition)
Fart (exhaust)

The video only shows suck, bang and a bit of fart...

[Mental Trousers]

I like these illustrations from wikipedia.

http://en.wikipedia.org/wiki/Two-stroke_engine
http://en.wikipedia.org/wiki/Four-stroke_cycle
Shame that 2 stroke one isn't a little larger cos it's a bit hard to make out whats happening around the piston etc. But it shows the effect of the exhaust pulse beautifully.

[deanohit]

Thats a pretty darn cool vid, imagine the pressure and heat on the camera.

[*caution*]

Thats a pretty darn cool vid, imagine the pressure and heat on the camera.

Something around 9000kPa of pressure and 3000K temperature, or 90 atmospheres and 2728C.

Depending on the fuel make up and quality, so that camera would have to be one serious piece of kit....

[Steam]

...so that camera would have to be one serious piece of kit....
Just two tiny fiber-optic fibers epoxied into a tiny drilled hole, one for the light and one to carry the image back.

[shafty]

Cool vid alright; it's always been hard for me to imagine that cycle happening 166 times A SECOND at 10,000 rpm tho!

[*caution*]

Just two tiny fiber-optic fibers epoxied into a tiny drilled hole, one for the light and one to carry the image back.

So you were lying to us all earlier?


This is quite interesting, I wonder how they did it?....

[Steam]

So you were lying to us all earlier?
You're quick to accuse aren't ya. You must live in a sadly untrusting world. Too many steroids causing mood swings and paranoia?

I wondered how they got a camera to go that fast, as the engine would be cycling at 18 times a second at idling rpm of maybe 1100 and there are a lot of frames in one of those 18 cycles to get that slow motion, that adds up to a really really fast camera.
I was wondering if they perhaps synched the frame rate to the engine speed, (like 17 frames per second when then engine is going 18 cycles per second) and so got a film that was actually made up of lots of different cycles but of course looked like a seamless cycle. Which might account for the shakiness of the film.

[stanko]

good job you guys dont work at the tax dept

10,000 rpm is 83 cycles per minute

1,100 rpm is 9.16 cycles per sec

1 cycle take 2 revolutions or 720°

[Steam]

10,000 rpm is 83 cycles per minute

1,100 rpm is 9.16 cycles per sec

1 cycle take 2 revolutions or 720°
Let he who is without sin cast the first stone. John 8:7 :2thumbsup:bleh:
But you are right, thanks for pointing that out.

[Ocean1]

Cool, clearest video I've seen. May have been shot through a quartz window, reasonably old trick. The high speed camera is impressive though...

[*caution*]

Too many steroids causing mood swings and paranoia?

Hahaha, classic....only when my dealer can't get me the good stuff!!

I've seen portable cameras that can shoot at 16,000fps, not sure what the fastest around could do, or the type you'd use for that.

[RantyDave]

This is quite interesting, I wonder how they did it?
Looking at how jittery it is I suspect they have a fairly vanilla high speed camera running very very slightly faster than the RPM of the engine. So each frame is taken at a very slightly different place in the combustion cycle, but on a completely different actual cycle. So 6000RPM = 100 per second so you'd need to take at about 100.5 fps. Easy with the right gear. Presumably they lit it with a strobe doing a similar stunt.

Must've been fun. I want to make one now.

Dave

[Wannabiker]

....thought they'd just used a really slow engine like a honda.....:msn-wink:

[Mr. Peanut]

Fairly low compression engine too (or rich), yellow flame.

[stanko]

Let he who is without sin cast the first stone. John 8:7 :2thumbsup:bleh:
But you are right, thanks for pointing that out.


Good spotting, but dont worry Im a Cathloic and we can have our sins wiped at a moments notice

[speedpro]

Something around 9000kPa of pressure and 3000K temperature, or 90 atmospheres and 2728C.

Depending on the fuel make up and quality, so that camera would have to be one serious piece of kit....

The cameraman would be a seriously "hard" dude as well, and a bit tiny.

[Steam]

Good spotting, but dont worry Im a Cathloic and we can have our sins wiped at a moments notice

Lucky bastard! I'm Buddhist and it takes about ten thousand lifetimes for us.

[Slingshot]

I wonder if you could cast an engine casing out of glass for the purpose of viewing the Otto cycle.

[Steam]

I wonder if you could cast an engine casing out of glass for the purpose of viewing the Otto cycle.

No: because as *caution* said "Something around 9000kPa of pressure and 3000K temperature, or 90 atmospheres" in an engine.
but if you just wanted a moving model, it sure would be pretty.
I will try to google it to see if someone has done it.

[Slingshot]

No: because as *caution* said "Something around 9000kPa of pressure and 3000K temperature, or 90 atmospheres" in an engine.
but if you just wanted a moving model, it sure would be pretty.
I will try to google it to see if someone has done it.

Good point...but it could be really think glass...like really really thick glass.

[Steam]

Good point...but it could be really think glass...like really really thick glass.

Yeah, a massive thick cube, with a real low pressure combustion, just enough to make it all go around. Metal parts, just a transparent engine block. Good idea for some eccentric bastard with masses of money! Or maybe a solid cubic meter of diamond.

[discotex]

Or maybe a solid cubic meter of diamond.

Nah, that'd be reserved for Posh's next engagement ring.

Edit: come to think of it having a cubic meter diamond ring with a working engine inside might be right up her alley...

[Steam]

Nah, that'd be reserved for Posh's next engagement ring.

WHAT??! Posh and Becks can't break up! Their relationship is the very foundation of Western Civilisation! If they fail then the hordes of Mecca are upon us.

[Grub]

Fairly low compression engine too (or rich), yellow flame.

Yeah and a crappy flame-front. all the fuel burn is around the edge of the intake as if it's slightly leaking. Good spot ont he mixture, I hadn't seen that.

[smoky]

What does this lead you to believe about the video? Old-school engine?

the vid is cool man

It only shows the compression and power strokes of a 4 stroke engine
- 2 strokes missing

[Slingshot]

the vid is cool man

It only shows the compression and power strokes of a 4 stroke engine
- 2 strokes missing

Looks like three and a half strokes to me.

Intake, compression, power and the first part of the exhaust stroke.

Remember, more that two strokes is a wank.

[smoky]

Looks like three and a half strokes to me.

Intake, compression, power and the first part of the exhaust stroke.


your right - you can see three, wonder why they didn't show the exhaust

[discotex]

your right - you can see three, wonder why they didn't show the exhaust

My guess is that they ran out of tape/storage on the high speed camera.

[Roj]

Cool, clearest video I've seen. May have been shot through a quartz window, reasonably old trick. The high speed camera is impressive though...

Nah, they have developed a camera that can catch an aussie with their mouth shut:chase:

[Ghost_Bullet]

Awesome clip. Interesting to see the real deal of what is goin on in the inside.

[Mr. Peanut]

The intake cycle makes me think of the human heart. Funny that.

[EJK]

lol Nitros hitting at 00:40:?
More Nitros at 1:00? lol