WHY IS A FLAT 6 BETTER?

[samm_cvr6 0]

Does it sap more power or something if the engine is Horizontal as opposed to vertical flat 6? :?

Just thinking about why Porsche/BMW use this so much in there marketing :wink:

[Kevin Bacon 5]

Lower centre of gravity and balance :D

 

As with most engines though, they're usually packaged around space constraints. Porsche flat 6 - lack of vertical space in 911. VW VR6 - lack of space in Golf/Corrado/Passat full stop!

 

Dunno why Subaru and Alfa went with flat engines as there's enough room in their bays for normal inline 4s. Probably done for handling.... i.e. a cylinder head on either side of the crank centre line and lower down in the car.

 

AFAIK there is no power advantage with a flat/boxer engine as such.

[samm_cvr6 0]

I see, all makes sense now. Cheers, yr a wealth of knowledge!

[TomB 0]

Apparently flat engines are more reliable in terms of little niggles...but when they go wrong they do so in a big way.

[Jimjam 0]

I thought BMW's were straight six? Or am I wrong?

[dr_mat 0]

Yep, BMW use upright, straight sixes.

[Musicman 0]

Check out this site

 

http://www.autozine.org/technical_school/tech_index.htm

 

Notably the 'engine smoothness' section at the bottom.

 

Lots of interesting info about VR6 power plants in there too ;)

[Flo 0]

thats a great link!

 

I exclaimed out aloud when i saw how ingenoius the camshaft arrangement for the 24v VR6 engine was.

 

You cant beat the germans (and dub engineers) on some things.

[CoxyLaad 0]

is it not all about the inertial forces acting on the pistons?

 

if 2 pistons are going in and out symetrically on a flat 6 they will cancel each others interia out and not pull the engine about?

[willwoll100 0]

is it not all about the inertial forces acting on the pistons?

 

if 2 pistons are going in and out symetrically on a flat 6 they will cancel each others interia out and not pull the engine about?

 

That is correct, 1 gold star for Coxy :wink:

[Henny 0]

is it not all about the inertial forces acting on the pistons?

 

if 2 pistons are going in and out symetrically on a flat 6 they will cancel each others interia out and not pull the engine about?

 

That is correct, 1 gold star for Coxy :wink:

 

Bugger, was just about to write that.... :| :roll:

[rado-steve 0]

and flat 4's and flat 6's make very nice noises :)

[slot 0]

and flat 4's and flat 6's make very nice noises :)

 

Ha ha !! bugger the tech stuff , they sound the bollox :thumb right:

[samm_cvr6 0]

yea saw a new M3 really giving it some off the lights the other day and the sound- oh yes!, looked like it hit about 50 in 1st gear, just kind of sounded like a metallic sound becoming a roar.

[Kevin Bacon 5]

is it not all about the inertial forces acting on the pistons?

 

if 2 pistons are going in and out symetrically on a flat 6 they will cancel each others interia out and not pull the engine about?

 

Well not really. Jump in a Subaru, 911, Beetle or Alfa and you can feel the car physically rock side-to-side as you crank it over. Or is that what you meant in that vertical engines don't do that?

 

The only way to counter act interial forces is with counter rotating balancer shafts, which is what the 944 4 pot and 911 use.

 

Engines also exert a gyro effect at high rpms and it's better from a handling point of view to have the gyro forces lower down in the chassis.

 

Oh god Haywire's talking pap again.....feel free to disagree!

[HiAsAKite 0]

Thats right.. they use balancer shafts.. whereas an inline 6 is perfectly balanced (depending on firing order) in both first and second order vibration... hence silky smooth....

 

And a VR is almost an inline 6 (inline 6 with a burble!)

[dinkus 10]

I'm sure the good doctor will have more to say on this... :lol: