Straight 6 Vs V6

[Jack-]

I heard the the straight 6 is smoother running, and produces more low torque in the rev range than V6's...

I don't really know :S

What's better a V6 or a straight 6 and why?

[itchy]

after owning a RB25DET, and a 6A13TT, i'd say the straight 6 makes a better note, but the V6 is better in every other way.

the V6 has plenty of torque all through the range

Edited May 23, 2008 by mungell

[Black Widow]

I heard the the straight 6 is smoother running, and produces more low torque in the rev range than V6's...

I don't really know :S

What's better a V6 or a straight 6 and why?

Ok this may not be the most educated answer ever..but i would believe it depends on the actual motor...like i'm sure an RB26 would run differently to like an commonwhore motor

[KezR33]

My Dad told me that my grandfather used to own a sports car with a dirty great straight eight under the hood.

I just like the sound of straight eight.

[FATAZZ]

does the gravity difference between straight 6's and V6's have any effect on performance/wear?

Just thinking how ones straight up and down and the other is angled,does it help? any benefit?

[GTR-32U]

or another question...which has the beefier bottom end...I still prefer the straight 6...

Edited May 23, 2008 by GTR-32U

[Interloper]

too many questions, lol.

Straight 6's are definitely the smoothest running - i read that in a recent issue of Motor Mag .

[Kinks]

inline 6 and flat 6 engines are intrinsically balanced, so they run very smoothly. every other type of engine (until you get to 12 cylinders) is not balanced. balance shafts are installed next to the crank which offset this vibration but you can never do the job perfectly.

The torque curve has more to do with the other design aspects of the motor. You can design an inline-6 to have massive low-end torque (most serious diesel engines are inline-6).

after owning a RB25DET, and a 6A13TT, i'd say the straight 6 makes a better note, but the V6 is better in every other way.

the V6 has plenty of torque all through the range

That's not really a fair comparison, the Galant engine is a twin turbo which gives you more flexibility in how you develop boost (and by relation, torque). Also, Galants are rally cars.. where midrange torque is your bread and butter. Skylines are circuit cars, and it's all about top end on a circuit.

[VB-]

V6's have a much shorter crank, which should add to strength i think, but obviously theres alot of other factors which contribute to that too

V6's are also more compact, so they can fit into smaller cars, and theres some reason that they are better for emissions apparently.

Edited May 24, 2008 by VB-

[Ronin 09]

generally inline 6s are cantered over to one side to allow better clearance and lower COG.

just FYI

Straight six is "simpler" too in that you don't need two sets of heads, etc (let's disregard VW's 15deg V6 for the timebeing as it's a cheater broken straight six anyway... lol)

[R34GT-t_07]

A v6 can produce more power then a strait 6 when modefied but the the strait 6 can hold power better then the v6 Example: Strait6 500hp V6 500hp the v6 would crack faster then the strait 6 would under havy driving.

[R338OY]

They're different configurations so you're wasting your time seeing which is 'better'. They've both been around for many decades so obviously they both work effectively.

I like the I6 better for its smoothness, but i wouldn't knock a V6 based on that reason. Being behind an RB or a VQ engine, they both sound and rev great and both are torquey.

The torque curve has more to do with the other design aspects of the motor. You can design an inline-6 to have massive low-end torque (most serious diesel engines are inline-6).

Skylines are circuit cars, and it's all about top end on a circuit.

You can design an engine to do anything you want. The parameters between all engine components functions, cylinder head capability, use of forced induction, displacement, gear ratios, fuel maps etc. are so wide that a 4 cylinder can be built to outdo an I6. It depends on the engineering requirements.

And no, Skylines are road cars.

Depending on the circuit of course, midrange and torque are usually more important than top end. Torque pulls you through corners, and is what allows easier overtaking. What's 10,000RPM going to achieve over usable torque? Nothing, because top end RPM's are a measure of the engine's speed, not the maximum power available to pull you through a hairpin.

V6's have a much shorter crank, which should add to strength i think, but obviously theres alot of other factors which contribute to that too

How many RB cranks break?

generally inline 6s are cantered over to one side to allow better clearance and lower COG.

just FYI

Straight six is "simpler" too in that you don't need two sets of heads, etc (let's disregard VW's 15deg V6 for the timebeing as it's a cheater broken straight six anyway... lol)

Spot on. The COG is even better on a flat-6.

Yes, a V6 is more complex (in the number of parts anyway).

A v6 can produce more power then a strait 6 when modefied but the the strait 6 can hold power better then the v6 Example: Strait6 500hp V6 500hp the v6 would crack faster then the strait 6 would under havy driving.

They can both produce big power. No, they won't just crack because of their piston configuration. Detonation or an oil failure would be more likely to kill the engine rather than its shape. A conrod might crack from excessive heat/force, but that can happen on any overpowered engine.

But in saying that I6's are used more commonly for large industrial machinery. It's better balance, hence reduced vibration, makes it more suited to large power (esp. torque) applications. Think of trucks used for mining, carring thousands of tonnes of cargo. A V6's inherent configuration would be unsuitable in this regard.

To illustrate, think of a TOLL truck's 80L or 90L I6 engine used to ship packages interstate. The vibrations we feel in 2.6L engines are amplified greatly in a 90L engine. It's 34.5 times greater displacement, so imagine 34.5 times more vibration coming from your engine bay.

Then imagine you have a V6 in the same situation

Edited May 24, 2008 by R338OY

[Sandeep]

i don't really know which is better but here's some pics:

vg30dett in Z32:

RB26 in Z32:

rb engine is longer, the radiator was moved further forward so there's going to be more weight further forward, not sure about the weight difference between vg30 and rb26 either. but much more room to work

[Kinks]

A v6 can produce more power then a strait 6 when modefied but the the strait 6 can hold power better then the v6 Example: Strait6 500hp V6 500hp the v6 would crack faster then the strait 6 would under havy driving.

Great. Thanks for that gem of knowledge.

And no, Skylines are road cars.

The "GT" designation stands for "Gran Turismo" or "Grand Touring". Skylines were built as enduro racers, not dropping down to the shops to get some milk. A Hyundai Excel is a road car.

What's 10,000RPM going to achieve over usable torque?

What's usable torque going to achieve if you have to change up a gear at 3,000RPM? When was the last time you were out-dragged by a bus? Why do you think F1 cars rev to the sky rather than rely on bottom end torque?

It's all down to gearing. It's better to make torque at high RPM because you can be in a lower gear, and the effective torque at the wheels is better.

To illustrate, think of a TOLL truck's 80L or 90L I6 engine used to ship packages interstate. The vibrations we feel in 2.6L engines are amplified greatly in a 90L engine. It's 34.5 times greater displacement, so imagine 34.5 times more vibration coming from your engine bay.

90L engine? hahahaha.. you're kidding right. I think you mean 9.0L. Most prime movers use turbo diesels around the 9.0L mark (eg Volvo FM-9 prime mover is 9.4L turbo diesel). Don't pull figures out of your arse.

I think I'm done in this thread.

[VB-]

LOL @ TOLL trucks imagine fuel costs on a 90l motor hahah

[Duncan]

yeah the long crank in the straight 6 never causes problems. thats why rb motors never have problems with bent cranks, cracked oil pumps or spun bearings.

[Haysey]

V6 is better, you can have two dirty big turbos hanging out of the bonnet on either side...

Example

Bird Eater!!

[chris_r31]

AMEN^^^^^^^^

[mystery_kid]

where can i get me one of these 90 litre engines?

[Kranker]

You cant really say which one is "better"

V6 is more compact, but is more complicated (ie complex intake, double the cams)

Straight 6 is simpler but has a longer crank, so more load on the end furthest from the flywheel but is smoother and has some natural balance.

Its not the configuration of the cylinders that makes or breaks an engine it is how it is designed. Bore, stroke, compression ratio, head configuration etc has a far greater affect on an engine than whether its a V or straight.

There are examples of good and bad I6 and V6 engines

And to Kinks,

the reason F1 cars rev to 18k+rpm is that they are limited to a very small capacity. Being as Kw = (Nm x rpm)/9550, for these little (ie. not very torquey) engines to make the power levels that they do, they need to rev like crazy and be designed to make what little torque they can at those high revs.

And you are right, it is all down to gearing, but that same principle applys to low revving cars aswell, just look at the Audi diesle Le Mans race car, it wont even pull 5,000rpm, but thanks to clever gearing the thing is increadibly fast. But this is all off topic.