I6 vs V6

[LethalLeigh]

It seems that the inline 6 motor is often panned as archaic technolgy as compared to the V6, yet most of the V6s I have encountered seem harsh. Is it just me, but is almost all of the 'famous' six cylinder motors we revere a straight six?

I thought I'd pass it to the crowd to see some comments and opinions.

[Fairlane]

The finest 6's in the world are I6's, nissan RB motors, BMW motors, classic HEMI 6 and the Jaguar 3.8L.

In fact i pretty sure that an I6 has about the best balance of any motor except for a V8 or a V16. Other motors need balance shafts and all that, personally i mainly prefer the I6 because its easier to work and yes ive have had both I6 and V6 motors.

Pros- Damn easy to work on
only one set of rocker gear/head - less to go wrong
inherent balance and reduced vibration

Cons- Takes up a lot of space
-Can upset balance of car with considerable length
-Useless for FWD configuration

[Joes_meat]

I really like straight sixes. They make a much better noise than v6's - especially at high revs (Just listen to the BMW M3.) Straight sixes are inherently very balanced, as fairlane said above. No balance shafts required - lower rotating mass. Straight 6's are so easy to work on. Changing an O2 sensor on the EF compared to the VS - guess which one had me laying in the dirt.

The Buick V6 that's in the Commodores used to be in Buick trucks in the 60's. Back then it didn't have a balance shaft. The engine was so rough that they'd regulaly snap engine mounts.

The problem with straight sixes, is they eat into interior space. In the Falcon it's not a problem so much, as it can be opioned with a V8. But for a car that only comes with one type of motor, a V6 makes more sense, because you can make the engine bay shorter and have more interior space in the same sized car. It's not a big difference, but this is the reason Audi push their motors as close the the headlights as possible.

There have been some great V6 engines too. Like the 3.5L Nissan in the Maxima/350Z/Murano is widely regarded as one of the best engines ever made. And the uh... Can't think of any more.

[SSBUB]

Originally Posted by LethalLeigh

It seems that the inline 6 motor is often panned as archaic technolgy as compared to the V6, yet most of the V6s I have encountered seem harsh. Is it just me, but is almost all of the 'famous' six cylinder motors we revere a straight six?

I thought I'd pass it to the crowd to see some comments and opinions.

your asking this q in a ford site? :togo:

[4.9 EF Futura]

A V6 is inherently unbalanced, is it not? i.e. 3 pistons either side... hence need for a balancing shaft??

V6 may be considered more advanced because they are often shoe horned into smaller FWD cars??

[Raptor]

Oh goody, this old favourite again.

Rather than have me rant on read through this and make up your own minds;
http://www.autozine.org/technical_sc...dex.htm#Engine
Particlularly the pages on smoothness

In short a V6 is better if packaging and both N-S and E-W orientation is a priority, also some benefits by localised mass in a shorter length - get the weight well within the wheelbase. For just about everything else an I6 is better

Originally Posted by Fairlane

.....
In fact i pretty sure that an I6 has about the best balance of any motor except for a V8 or a V16......

You've let the V8 brainwashing get to you Fairlane. An I6 is better balanced than a V8 (which is really only 2x4cyl spliced together) though a V8 will deliver smoother power delivery as there is a pulse each 90deg of crank rotation. The only thing better balanced than an I6 is a V12 (2xI6)

[DivHunter]

Sorry I can't see how a V can be more balanced than an inline of any shape or size if you ignore anything but the piston configuration.

[MRJUCY]

A V engine has nothing to do with technology it is just a way of packaging.

[Polyal]

the I6 engine is AWESOME, if only they would make a serious HP version that revs more id be even happier.

[gozza]

i love my I6...smooth and its sounds nice with a good system...a nice burble....doesn't sound as good as an 8 but better than most 6's

[macca_779]

Horses for courses I've driven a TT V6 RS4 and it makes a Falcon Straight 6 feel like a bumbling idiot. Then again thats how the Falcon 6 makes an Alloytech look.

[troppo]

Originally Posted by LethalLeigh

Is it just me, but is almost all of the 'famous' six cylinder motors we revere a straight six?

With the exception of the V6 engines in the 70's GT Capri's, yes.

[Stav]

I dont know guys?? If the car goes and doesnt use too much fuel..who cares? V6 V8 V20 or straight 6.If the engine is designed well then it should be ok. It depends what you are used to .

[Ryan]

Of course im going to go with the I6s. :

After all, one of the best 6 Cylinders Holden ever had, was the RB30.

Like I always say "The RB30 is the best engine, Holden never built".

[gozza]

has there ever been a I8?

[WILDTRAKPX2]

Originally Posted by SSBUB

your asking this q in a ford site? :togo:

And Ford don't have V6's : Good one!

[Ryan]

Originally Posted by gozza

has there ever been a I8?

Yeah mate.

They were used in the 30s, I think.

[LethalLeigh]

Originally Posted by SSBUB

your asking this q in a ford site? :togo:

I ask this question because I have an interest in what constitutes good engine design. Whilst some people here can be one eyed Ford fans quite a few of the folk on here have taken a liking to Fords after years of experience. The Falcon and Territory are probably the only Fords left that use an I6 motor anyhow.

Also, I think FIAT used an I8 before WWII. It's rarely used now because of packaging (ie length and weight).

[4.9 EF Futura]

Leigh - some good reading to be had here:

http://www.autozine.org/technical_sc...ne/smooth1.htm

It appears to address the nature of your query....

[AU:PROJECT:UTE]

Its remotely related to this thread but my tractor has a 6.8l inline 6, big turbo'd John Deere tractor. Only revs to 2800rpm but its the 560nm of torque that it produces at 2200rpm is enough to tear tree roots out of the ground like no tomorrow when ripping a paddock :thebirds:
Funny how its only rated at 135hp
Fooken big donk though :
Just thought I'd add something odd for a fridy arvo!
Have a good weekend :

[aimzes]

has there ever been a I8?

yeah theres one in the mechanical area at the UTS. i think its a rolls royce... im sure it had that cast into the block, been a while since i saw it though. and no they wouldnt start it up for me lol.

freakin huge thing.

[act2617]

Originally Posted by gozza

has there ever been a I8?

Yes a few.

http://encyclopedia.thefreedictionary.com/Straight-8

http://encyclopedia.thefreedictionary.com/Straight-12

[Rev28K]

Originally Posted by Joes_meat

There have been some great V6 engines too. Like the 3.5L Nissan in the Maxima/350Z/Murano is widely regarded as one of the best engines ever made. And the uh... Can't think of any more.

There have been a couple of other good V6’s –
Mitsubishi’s 3.5 (Pajero Evo model),
Fiat/Ferrari 206 GT alloy blocked 2.0 litre V6 – later on the iron blocked 2.4 litre V6 (shared with the Lancia Stratos),
Alfa V6 (started of in the GT 2600 I believe and went out to 3.2 litre (and 3.5 litre Autodelta mods)),
Cologne Capri V6 from the 70’s Capri,
Nissan VG30TT,
Audi RS4 (and Allroad) TTV6,
Renault F1 Turbo V6 (Turbo V6 was the packaging go in those days).
Expand the V out in to 180 and you get a Porsche flat 6 (started out at 2.0 wound up as 3.8).

Do you think that Lexus would go to V6's on their new models if they couldn't get them well balanced? The Holden V6s need a balancer shaft because they are a 90 degree V6 (cut down V8) where as most V6s designed from scratch are 60 degrees.

Volvo is fiddling with a transverse straight 8 for FWD applications now.

[4.9 EF Futura]

Originally Posted by AU:PROJECT:UTE

Funny how its only rated at 135hp
:

hp = torque x rpm /5252!!!!

A friend took me for a ride in a bentley a few years back... 4L inline 4... cylinders the size of your head.... never sounded like it was revving but still gave a good kick in the backside.

Lol - more attention was paid to operating the crash type gear box!! Crunch crunch...

[SSBUB]

Originally Posted by Shockwave XR8

And Ford don't have V6's : Good one!

this is true, but when you think ford, do you think v6 or inline 6? your first thought is inline 6 no matter what you say :yeees:

and just to throw some a spanner in the works, the alloytech recently named in the top 10 engines in Wards Autoworld and Wards Engine and Vehicle Technology Update.

But before anyone gets their back hairs up, the 3.6l wasnt the award winner - it was the 2.8l turbo found in Saabs 9-3 aero and Opel's Vectra.

But i do agree with one of the statements made previously. As long as it goes, doesnt give you too many hassles and has a descent amount of poke, then who cares?

[turboute]

The only reason that V6's appear to be smoother than some I6's is the amount of money spent on counterbalance shfts etc. I6's (and their multiples) are the only engines that do not require counterbalance shfts to stop them vibrating to peices. 60 deg V6's still have this problemalthough it is not as pronounced as in a 90deg V6 (same with V8's). Also the lack of counterbalance shafts means that I6's will have less rotating mass.

[Rev28K]

From: http://www.roadandtrack.com/article....4&print_page=y


Slant On Sixes
I was told by a reputable mechanic that out of all types of engines, a straight-6 is the perfect configuration. It is the smoothest, mechanically strongest and the most durable engine. As an example, the Toyota Supra and BMW M3 come to mind. Both cars had legendary engines. I write "had" because Toyota stopped making Supras and BMW will switch to a V-8 for its new M3. Was my mechanic right, and if so, then why are inline-6s not that popular and many automakers prefer V-6s or even V-8s? And why do all the big semi-trucks have straight-6s?
Giedrius Zioba
Las Vegas, Nevada
No engine configuration is perfect, and while the straight-6 offers many compelling benefits, some of its defining characteristics don't mesh well with current passenger-car fashion. Chief of these is the layout's long length and resulting packaging considerations, especially in front-wheel-drive applications where the engine sits "sideways."
Furthermore, unless laid over, à la Chrysler's Slant 6 or the celebrated Mercedes-Benz 300SL Gullwing's 3.0-liter, a conventional inline stands taller than a vee engine.
As for the inline-6 being mechanically strongest, well, it's a great layout, but its long crankshaft (longer than a V-8's) needs attention from the designer to assure adequate stiffness. This often results in an expensive-to-manufacture crankshaft and seven main bearings. That's two more bearings than for a V-8, for example, meaning more friction and engine weight. Alternatively, the designer may specify a lower rpm to avoid crankshaft stiffness issues, as in light-truck applications.
To its credit, the straight-6 is in perfect primary and secondary balance, leading to its typically smooth-running personality. But then, so is a counter-weighted 90-degree V-8, and the V-8 more easily supports a larger displacement, a shorter, stiffer crankshaft, tighter engine compartment packaging for a shorter overall vehicle length, more concentrated engine weight for snappier handling and a lower cowl height.
And just for the record, the Class 8 trucks are often powered by V-8s as well as straight-6s.

[70caprigt3k]

either way is good as long as its built well it doesn't really matter i think the main advantage to the V Configuration is that it can be a compact package due to be able to vary the valley angle so it can be more used in varying applications i.e fwd and rwd and in small and larger engine bays. i wouldn't imagine there would be a performance advantage either way except possibly more even distribution of air/fuel and flow through the V6 (carby of course) but please correct me if i am wrong. I am a little biased towards the V6 though because the Essex V6 from the 70's capri is the sweetest 6 i have ever heard and done right they are completely smooth throughout the rev range.

[Iphido]

I6 are classic engines. All the early classic cars had I6's. Most have given up for the compromise of packaging, fitting into more models, FWD etc.

However i6 dictates a long bonnet, long bonnets on sedans are sexy. I6 sound diffrent (some say droney but I say sexy), and you can feel the noticibly smoother engine balance.

Ford has to keep the I6, its what defines the falcon. Sure modernise it, tweak it etc. But the I6 is fundementally good.

[muzz]

Sort of on topic,
why aren't there more narrow angle sixes like the VW 15 degree six? They seem to be an excellent compromise between straight 6 and v6. And they sound pretty neat too.