Difference between a regular V6 and inline 6?

[driverdriver]

I'm curious to know what is the difference between a regular V6 engine and an inline 6, like the ones found in BMW and Lexus IS300 are? Is there an advantage in power and economy in an inline 6? Different mechanical workings?

Simply curious.

[Jesda]

Technically I do not know the difference. But from the driver's point of view, it is said that the I6 has more torque and smoother acceleration.

[Q45tech]

Assuming the bore and stroke are equal both designs can make the same torque.

http://autozine.kyul.net/techn...3.htm

[PoorManQ45]

ISn't a I6 better balanced than a V6.

[PalmerWMD]

An inline 6 will be smoother than a V6 if everythin else is equal,

There is potential for better packaging efficiency in a V6 though ( less lenght) also the greate lenght of an inline arrangment places greater ( proportionate) stresses on the crankshaft.

Fred..

[DR.Q]

H-6 baby! That's where you get the balance. And some sweet sound to go with it.

[maxnix]

Thought 60° and 120° V6 were in primary balance also, not just 180° flat sixes.

Liewise, V12 engines of the same cylinder bank spacing are in primary and secondary balance.

Oh, perhance to dream!
Modified by maxnix at 9:29 AM 10/27/2004

[JedCoop]

A V6, has power and first order balance. However only 90 degreee V8's and I6's naturally have second order balance. Its been a *few* years since my automotive engineering courses, so I am scraping to come up with the precise definition of second order balance. I think it has to do with cancelling out sidewards shaking due to connecting rods.

[louiegz]

I guess another question would be, What's the diferance between an inline 4 and boxer 4 engine? I don't know about the sixes, all I know is that the 3.0 BMW inline 6 is a wonderful engine.

Thought 60° and 120° V6 were in primary balance also, not just 180° flat sixes.

One more to add would be the VW VR6. That one was, I think, a 30° V6. It made it great to fit in a tight space but they had to get around a heat issue witht the heads.

[DR.Q]

[QUOTE=louiegz]I guess another question would be, What's the diferance between an inline 4 and boxer 4 engine? I don't know about the sixes, all I know is that the 3.0 BMW inline 6 is a wonderful engine.

A boxer is horizontally opposed.

[JedCoop]

I looked this up, it bugged me I didn't remember this stuff.

In-line fours vibrate more than an opposed four. Both have first order balance, i.e. no mechanical vibrations that occur at the same frequency as the crankshaft RPMs.

Both I4's and opposed 4s have second order vibrations (shaking at twice the frequency of the crankshaft).

The opposed four is smoother having only "secondary" second order vibrations.... The inline four has "secondary force" vibrations, meaning it tries to "hop" twice every revolution, where-as the opposed four's vibration tries to rotationally "wiggle" the engine which is less noticable.

For a while Mitsubishi made 4bangers with a counter-rotating shaft to offset the crankshaft/piston secondary vibrations.

I believe that V6's have only rotational secondary vibrations. My old VW Quantum/Passat's five cylinder engine could never be even that smooth.

[louiegz]

I'm curious to know what is the difference between a regular V6 engine and an inline 6, like the ones found in BMW and Lexus IS300 are? Is there an advantage in power and economy in an inline 6? Different mechanical workings?

Simply curious.

I would think that another reason BMW uses the inline 6 would be for weight distribution. They boast about the 50/50 balance in their 3s. I guess with the I6, more of the engine can go behind the front axle so the car wont be as front heavy. The G35 tries to get as much of the engine behind the front wheels to try to do the same with a V6, but they only get 52/48. I guess with the V6 being so wide, there's only so far back you can go.