Recent comments in /f/gifs

FallenFae t1_iwgrgpl wrote

The only, and I mean ONLY thing I'd change here is to put a reflective edge around the obelisk, one that moves as the blue light from the rift edge and the pink light from the clouds overpower each other. I like the obelisk being vantablack™ but it was hard for my eyes to focus on it. Other than that, fucking incredible work. I love the perspective, it feels like all the air around me would be getting sucked past and into the rift. The atmosphere you've created is incredible!

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Brandon432 t1_iwgreof wrote

Reply to comment by therandomopera in How an engine works. by ooMEAToo

This animation/video is a bit simplified. In real life, a couple things are different. The part at the top of the valve (or linked via pushrods and rockers) that actually contacts the camshaft is called the tappet. Tappers can be “flat” (not literally, they still have a bit of crown) or roller style. In either case, the tappet is made of friction resistant alloy and does NOT break contact with the cam. It follows the entire lobe so there is no “striking” just rubbing. Roller tappers greatly reduce friction but increase mass. In either case, the cam and tappets are enclosed in the engine head and continually fed motor oil to reduce friction and dissipate heat.

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Strength-Speed t1_iwgp260 wrote

Just a question if anyone knows. The cycle is intake, compression, ignition, exhaust. That would seem to indicate the piston starts in the up position then draws in air-fuel as the first step. But what draws the initial piston down, before the engine starts, as no ignitions have happened yet?

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witzed1 t1_iwgnrd3 wrote

Strange valve timing gear configuration. Usually cam and crank turn in same direction. Maybe a model artifact but definitely not representative of modern engines.

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witzed1 t1_iwgmy47 wrote

Reply to comment by DekaFate in How an engine works. by ooMEAToo

The part, the connecting rod, connecting the piston to the crankshaft breaks. Usually due to some catastrophic problem like overheating or oil starvation. Something has prevented normal piston travel.

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myawesomeself t1_iwgmva8 wrote

Reply to comment by Waldron1943 in How an engine works. by ooMEAToo

I think this is what everyone expects, that the exhaust should be open near TDC so it might overlap with intake a little, however in the model it clearly closes completely somewhere around halfway up and there is a noticeable gap between the exhaust valve closing and intake opening which is the unusual timing people are talking about.

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