Quote:
Originally Posted by Efthreeoh
This is a complicated subject. But the basics are this:
Engines vibrate for a bunch of reasons, but mainly because of a phenomenon called the "rocking couple". It's when two pistons don't balance each other. Put a third piston (cylinder) in the system and it can counteract the rocking couple effect. But that depends on the bank angle of the block and design (position) of the crankthrows. An inline six has natural elimination of two rocking couples, which makes it inherently smooth and vibration free. A flat 6 is nothing more than an inline six laid down flat, which is why flat sixes are low vibration designs. Inline and flat sixes are known as naturally balanced engines. I have both designs in my vehicles. The other engine I have is a small block. The Wife's Z4 has the M44 in it, which is a paint shaker in comparison.
A 90 degree block angle (an inline engine block is zero-degree and a flat block is 180 degree) for a V8 is another very low vibration design. A 60 degree V6 is also very low in vibration (harmonics) as well.
A lot of car companies to save tooling costs will build 90 deg. V6 engines because they can be built on the same 90 deg. engine line as the V8 engine. Mercedes did this back in the early 90's when it dropped the inline 6. Most good V6's are 60 deg. blocks. 90 deg. V6 blocks need a balance shaft to act as counter weight to eliminate the rocking couple effect.
Anyway that's a real short explanation in simplistic terms. But as others have said, it all depends on packaging of the driveline and desired architecture of the vehicle.
|
I could be wrong, but aren't flat sixes and V-sixes configured somewhat differently than an inline six as the block is a lot shorter?