Why don't inline 4's use this type of crank? Balances primary forces like normal but without fucked rocking couples?
Why don't inline 4's use this type of crank?
Why don't inline 4's use this type of crank? Balances primary forces like normal but without fucked rocking couples?
You're just shifting the problem to another aspect.
How?
Fortnine did a nice video on it recently. Motorcycles, but engines are engines.
Can you please post the link, just for clarification I'm not talking about a crossplane online four I'm talking a flatplane but in that configuration
Yamaha R1 uses a crossplane I4.
I'm not talking about a crossplane, the picture I posted is a up down up down FLAT plane
Whereas in the Yamaha it's TDC middle middle BDC
The primary forces will be worse, you are creating two rocking couples because pistons traveling the same direction are a different distance away from the center of mass.
>pistons traveling the same direction are a different distance away from the center of mass
This is the reason regular I4s have a perfect primary balance, it's secondary forces that are the problem because momentum of pistons and whatnot and IIRC that's a problem that can't really be fixed with four cylinders without greatly negatively affecting primary balance
like said, the primary balance will be worse. the engine would rock back and forth due to the center of gravity for each piston pair having been offset
See
the red line i put on your original image marks the center of the engine, now look at the rocking couples that i outlined in squares in relation to the center line.
I know what a rocking couple is but the two rocking couples in this situation cancel out because two rotational forces going in the same direction but connected to each other cancel each other this is why two gears meshed together can't be spun in the same direction because the right side of the first rocking couple is trying to rotate the crankshaft down while the left side of the second crankshaft is trying to rotate it up it should have BETTER balance because in the up down down up crankshaft the two rocking couples are BOTH exercising a downward pressure on the inside of the crank and and upwards pressure on the ends
As I said, the distance of (pistons traveling in the same direction) from the center of mass is different
This means that the levers are unequal, therefore the resulting forces are unequal and won't cancel themselves out. This is literally high school physics
And if that doesn't convince you, don't you think that over the last 100 years, car manufacturers who spend billions on r&d wouldn't come up with and adopt this configuration if it was any good?
What the fuck are you talking about the centre of a rocking couple is at the centre of the next closest piston moving down lmfao, both situations have two distinct rocking couples at the exact same position
jesus christ anon. if you can't see why the engine wouldn't rock back and forth in that pic then i can't help you any more.
except it does dude, you can't just say it doesn't. This is why every single makers have 1 and 4 opposing 2 and 3
i'm talking about the lower half where 1 and 3, and 2 and 4 are paired.
why do you think straight 6s have opposing pistons paired?
I thought we were talking about i4's
just pretend cylinders 1 and 6 don't exist. the point is to show the opposing pistons cancelling each other out. if it was paired 1-4, 2-5, 3-6, there'd be crazy vibrations.
Take two gears try spinning them disconnected in the same direction then change direction now mesh those gears and try to do the same thing, you can't because the rotational forces cancel out and there's no back and forth motion lmfao
fml. i meant if you can't see why the engine WOULD rock back and forth in the bottom pic.
>the first rocking couple is trying to rotate the crankshaft down while the left side of the second crankshaft is trying to rotate it up
Ok, a little practical exercise, since you don't seem to get this
Stand up straight and put your arms out to your sides, like a crucifix position
First, try to move your arms up and down, both in the same direction. Like a bird would flap its wings, do it as fast as you can
Second, try to move them in opposite directions. Move one arm up while moving the other down. Again, as fast as possible
Now compare, in which of the two did your torso move less?
This is exactly what primary forces are, your configuration would cause the engine to shake from side to side because the forces try to make it rotate
That's fucking retarded situation because in that situation the second situation that is a single rocking couple and the first situation it's two
I'm getting a feeling that this is simply premium quality bait because no one can actually be *this* retarded
Like, even actual downies have some inherent, instinctual understanding of balance
In case it's not bait, well, you're wrong OP, you should've paid attention in high school physics but don't worry about it, not everyone is built to be an engineer
judging by OP's latest response, i don't think this is bait at all now.
godspeed in your engineering adventures OP
Couples prevent the pistons from stressing the crank.
Ok maybe this is an actual answer that makes sense, up down up down would prevent rotational vibration but result in a increase of stress at the crankshaft where the rocking couples connect
The couples balance each other during combustion stroke.
The Mustang GT350 does that, but with 2 of them in a flat plane V8. It requires massive dampers to deal with the primary imbalance, and it would only be worse on an I4.