Thread replies: 6
Thread images: 2
Thread images: 2
File: 1476487169006.jpg (19KB, 480x360px) Image search:
[Google]
19KB, 480x360px
Can anyone help me understand engine balance and shit?
Primary forces from the piston itself moving up and down are countered by the other pistons, which means that 1 piston engines, 3 piston engines, and 5 piston engines require an extra weight to counter the force of the last piston. On top of that, even 4 cyl engines have counterweights so that the balance of the several pistons dont bend the crank too much and fuck up lifespan. Right?
And the cranks have con rod journals that should be at 1/4 of the total angle of 2 crank rotations (since its a 4 stroke engine) compared to the next cyl to fire, all of this just to balance the primary vibrations, right?
But considering all that, what makes the inline 6 so special and balanced? The V8 has counterweights per cyl bank that rotate to avoid too much bearing wear, but if secondary vibrations (the ones that exist in every engine but boxer) still need their own counterweight bullshit regardless of the amount of cylinders, what makes inline 6 so special? is it that since V6 are 3 per bank they are harder to balance or what?
>>
No one replied, OP, but i also want to know:
If the angle has to be planned in such a way that its 2 revolutions / Nº of cylinders, why is it that 60º V6 exist? wouldn't that make the crank have an entire revolution in which no power is given?
>>
>ITT: what is google?
An inline six engine is in perfect primary and secondary mechanical balance, which can be achieved without using a balance shaft. The engine is in primary balance because the front and rear trio of cylinders are mirror images and the pistons move in pairs. That is, piston #1 balances #6, #2 balances #5, and #3 balances #4, largely eliminating the polar rocking motion that would otherwise result. Secondary imbalance is avoided because an inline six cylinder crankshaft has six crank throws arranged in three planes displaced at 120 degrees. The result is that differences in piston speed at any given point in rotation are effectively canceled.
>http://www.bangshift.com/forum/forum/bangshift/general-discussion/10602-does-an-inline-six-crankshaft-have-to-be-re-balanced-for-lighter-custom-pistons
>>16470268
>implying if the crank is spinning there isn't any power
no
in short, it's the best V6 possible
>A V6 engine with a 60 degree included angle between cylinder banks hits the "sweet spot" in V6 engine design due to several desirable characteristics. Unlike most other V6 layouts, 60 degree engines can be made acceptably smooth without using a balance shaft. Although the engine will not be as smooth-running as an inline six or opposed six cylinder engine, modern design and mounting techniques can eliminate objectionable vibration.
>https://en.wikipedia.org/wiki/V6_engine
>>
>>16470826
>The engine is in primary balance because the front and rear trio of cylinders are mirror images and the pistons move in pairs
But wouldn't that mean that a 4 cyl car is also in perfect balance?
>Secondary imbalance is avoided because an inline six cylinder crankshaft has six crank throws arranged in three planes displaced at 120 degrees.
Makes sense, but again, wouldn't this also happen with a 180 degree 4 cyl engine?
>no
in short, it's the best V6 possible
Is that so? because last i remember most high end V6 sports car used 120º head and cranks that produced the most vibration but apparently performed the best
Also, if an inline 6 has a 120 degree crank profile bank, what makes a V6 with half that better? what's so good about giving each piston its own crank angle? and if its truly better, why dont we see stuff like 90 degree inline 4 and 45 degree V8?
>ITT: what is google?
>implying that i didn't googled everything and posted this when i couldn't find answers to my questions
>>
File: 45degreev8.jpg (19KB, 278x394px) Image search:
[Google]
19KB, 278x394px
>>16471082
>4 cylinder in perfect balance?
just stop
>I used the google
obviously you didn't
you didn't even look at the wikipedia page I spoonfed you
>can't understand that a V6 is two I3s pasted together no matter what angle the cylinders are at
>implying V4s weren't a racing design
>implying there were never 45 degree V8s
>>
>>16471185
>just stop
why? i am trying to understand this shit.
>obviously you didn't
you didn't even look at the wikipedia page I spoonfed you
I did. I read both engine design layouts in the wikipedia, the V6 engine, the inline 6 engine, and other websites and my questions haven't been answered. Would you mind please explaining to me why is that?
>implying V4s weren't a racing design
I never implied that? i just never saw them
>implying there were never 45 degree V8s
Were they? and if there were, why aren't they made nowadays if one crank angle per piston is supposedly so much better?
Thread posts: 6
Thread images: 2
Thread images: 2