So Rick, should the pilot screw go in or out?

How clean is your chamber?

 

Just as I had always imagined.
Thanks Mac, that was kinda neat.

 

Amazing!
Wow.
And, the Slo-mo even picked-up the Spark Plug firing!

 

This video is awesome! Did you notice the air leaking in around the intake valve while the piston was moving down during the power stroke? Or that the plug fired before the piston was all the way up. And all the carbon on the piston face? You can see it spark up when the fuel detonates.

Tons of information to be had in there.

 

If you watch closely enough ... you can see a backfire, or at least a "Popping-back" from a tight Intake Valve ...

 

when any of you be willing to explain what exactly is going on in detail in that video. its amazing. but alas, i am noob when it comes to engine workings. what are the right and left valves doing? is that air coming in when the right valve opens up. its really interesting.

 

How internal combustion engines work.

 

The INTAKE Stroke.
Intake Valve Opens, Piston from TDC to BDC draws-in Air~Fuel Mixture

The COMPRESSION Stroke
Valves Closed, Piston from BDC to 7~9 Degrees Before TDC. Air~Fuel Mixture is quickly compressed for detonation.

The POWER Stroke
The SPARK PLUG Fires, Mixture is Ignited, Piston forced down by exploding gases.

The EXHAUST Stroke
The Exhaust Valve Opens, Burn (or partially burned) gases forced out the Valve on the Up Stroke ... Exhaust Valve closes ... Intake Valve Opens:

The Cycle begins again!

 

The video shows an [incomplete] engine revolution: intake, compression, power then exhaust. (For some reason, the maker of the video omitted the exhaust stroke.) This engine is a "four stroke" engine. Each stroke is one of those listed above. A stroke is one complete piston travel, i.e. up or down. The intake stroke is when the piston--moveing down--sucks air and full into the combustion chamber by way of the open intake valve. As the piston changes direction, the intake valve closes and the piston then compresses the mixture--usually at a ratio of about 10:1--on the compression stroke. When the piston reaches top-dead-center, the plug sparks igniting the mixture. The mixture expands violently in all directions. By design, the most movable part is the piston so it is driven back downward in the power stroke. The force of the explosion is enough to carry the piston all the way down and around again to push the exhausted gasses out of the combustion chamber. As the piston comes back up on the exhaust stroke, the exhaust valve opens allowing the gasses to exscape. The process then repeats... and you go vrrrrooommmm!

Of course, this explanation is over simplified, but gives you a pretty good idea of what's going on inside the engine.

 

Suck, Squeeze, Bang, Blow, in that order .

 

The Exhaust Stroke and the Intake Stroke happen in the same revolution.
In many applications the "Leftover exhaust" not forced out is part of the Mixture for the next Intake Stroke.

That's why Headers and Straight Pipes change the Mixture to Lean. Without restriction, there's little leftover exhaust gases to help make-up the following Intake. Consequently, the Mixture becomes Lean as a result.

With stock pipes and exhaust the back-pressure prevents complete evacuation of the Chamber and the leftover becomes part of the next quantity of fuel to compress.

Headers and straight pipes just let it all out and the Intake needs to be adjusted for its absence or the new Intake Mixture is Lean.

 

Here's a link to an animated clip of what's being shown on the first link of this thread.

http://www.k-wz.de/vmotor/v_omotore.html

Hope this helps those who asked for more info.

 

This is obviously a fuel injected engine. judging by the speed of the incoming fuel charge. It's also a 4 valve head, though it is difficult to see initially. There is no valve problem with this engine, the mixture isn't uniform, which is why you get some yellow flame near the edges, which is actually curling up from the piston crown if you look closely.

 

I wonder why they used censorship to prevent us from seeing the exhaust valve close? Is this some kind of sinister political correctness? Perhaps they were trying to cover up the fact that it's not slow motion at all, but real time film of a H*rdley Driv*able at full throttle.

 

It's definitely a conspiracy! :lol:

 

oh man thanks for that explanation! i dont know why i never knew this.

but heres my next question...

how does the engine time the intake valve and the exaust valve? seems like they both happen on the up stroke of the piston. how does it know to not draw in air/fuel on the 4th cycle.

i am a sponge.

 

The Crankshaft is connected to the Cam Shafts by a Chain Drive and Sprockets.

The Cam Shafts are "Timed" to open and close the valves at the right instant.

 

Here's an animation of a 4 Stroke engine showing the cam and valves operating.


Here is a Video of a Camera in a 4 stroke cylinder