Smoothness of V6 compared to S6 engine.

Sep 07, 2013 63 Replies

Saturday's pointless question...



I understand that S6 engines are mechanically balanced in such a way that they are inherently smoother than 4 or 8 cylinder engines. Does the same apply for a V6, or does the move to a V formation reduce its smoothess in any way?



Thanks in advance.


The latter.

After a straight 6, a V12 is best.

Chris

But V12 can be noisy; just the chorus of cylinders.

S6, V12 can give nauseating roll movement of car when you blip the pedal e.g. in neutal while the car is stationary.

S6 and maybe V12 can have cooling problems for the rearmonst cylinders.

Nah T4 is actually the best engine, it can give up to smooth 300bhp these days.

T for Transverse. A boxer is compact and well suited for a low profile sporty car, but not particularly smooth. I don't think I could live with a subaru, but other people obviously dissagree.

I'm a born again biker and after buying a good used Divvy was a bit peeved at the vibration that came in at predetermined speeds.

I know the dealer and didn't doubt his comment that you won't get a

2,4,6,8 pot' engine that doesn't have any vibration at all at some speed or other. He said I would be best with a three pot machine where the engine runs much smoother.

Why are 3,9,12 pots so rarely used instead of 4,8,12 if that is the case?

Ah, memories of my 2-cyl Bradford Van, by Jowett. You could go so slow, you could count the ignition pulses. Steering, however, was a game of chicken.

F*ck it. I meant 3,9,12 etc sequences.

Not since they introduced water cooling...

Read the question the OP was actually asking; note the word 'inherently'.

Chris

surely a wankel engine is the smoothest with nothing being thrown back and forth to need counterforces to make it smooth

Sure there is water cooling, we know that. But engine still likes some air flow young Chris; it's not all about water. And what about if the water runs low, the rear cylinder is the first to go.

Who cares what OP was asking?

[...]

So stationary engines are a figment of my imagination then?

Care to cite a reference to proof of that sweeping statement?

Perhaps you might also like to clarify your statement in relation to the dominant under-bonnet layout of transverse engines?

That pretty much sums up your approach to posting I guess; spout some nonsense very loosely connected to the subject, but largely missing the point, then try to defend the indefensible.

Chris

Define "noisy".

Nothing to do with cylinder arrangement, just torque reaction that all engines generate in greater or lesser degrees.

Air cooling in car engines disappeared some time ago.

It's the cheapest (and probably lightest) conventional engine per BHP perhaps, that's all.

Tim

The orientation of an engine - longitudinal or transverse - has absolutely no bearing on the inherent vibrations from the layout.

I assumed, by your reference to power outputs, that you meant a turbocharged straight four by "T4". Again, the induction has no bearing.

The "smoothness" that the OP was referring to is solely down to the firing order versus the crankpin offsets. For V engines, the angle of the block makes a difference, too.

An inline 6 has a fundamental resonance at about 5000 rpm which needs to be addressed. But easily done with a damper on the crank nose.

With a V-6, it depends on the angle of the V. If it's 90, it will usually have balance shafts.

Db

Have you tried/owned and compared cars with longitudinal and transverse engines? Longitudinal crankshaft produces roll motion, whereas transverse produces pitch motion, which is much less due to length of car compared to width.

Yes, engine power doesn't scale so well with bulk of engine, mainly due to thermal problems.

Yes, the much maligned Jaguar 220 engine was a turbocharged V6 offcut of the Rover V8. Testers thought it sounded like a bag of nails...

[...]

But still nothing to do with the number or arrangement of cylinders then?

Chris

An S6 is usually longitudional, as are most V6. Only few exceptions.

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