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Whine Connoisseur
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Besides the obvious (size) what prompts a manufacturer to configure the cylinders in a "V" formation as opposed to "I". What are some of the adv. disadv. of each set-up?
 

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I just juxed this off of howstuffworks.com
http://howstuffworks.lycoszone.com/question366.htm


Question

I am buying a car and they talk about engines being an "inline" or a "V" configuration. Does it matter how you arrange the pistons?

Answer



There are actually three different engine configurations commonly used in automobiles:
Inline -- the cylinders are arranged in a line in a single bank:

Click on image to see animation



V -- the cylinders are arranged in two banks set at an angle to one another:

Click on image to see animation



Flat (also known as horizontally opposed or a boxer) -- the cylinders are arranged in two banks on opposite sides of the engine:

Click on image to see animation


You can find, for example, inline 6 cylinder engines, flat 6 cylinder engines and V-6 engines. If you built all three of these six cylinder engines to the exact same specifications -- same displacement, same valves, same intake and exhaust systems, etc. -- they would likely perform nearly identically. Displacement is displacement.

However, there would be a number of differences between the engines in use. Here are several of them to give you a taste:

An inline engine is long and narrow. In small cars in particular, a long, narrow engine mounted transversely can allow a very short hood. In an air-cooled engine, the inline configuration is sometimes harder to cool.
A flat engine is wide and flat. This gives it a low center of gravity.
A V engine is a compromise between the two. It tends to be more cubical in shape.
The inline shape needs only half as many camshafts as a V configuration (if using overhead cams), which can lighten things slightly.
There can be differences in the amount of metal required in the block, meaning that one type might be lighter than the other.
There can also be cost differences during manufacture.
Designers choose among a number of variables when deciding which configuration to use in a car. Variables include cost, space available under the hood, position requirements, existing manufacturing facilities, power to weight ratio, etc.

People sometimes get religious about engine configuration. If you are religious about any of these configurations, please write to me at [email protected] and explain your point of view. If there are some good comments I will publish them next week.
 

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There is no substitute.
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I heard from word of mouth (or advertising) that inline 6 is generally more efficient than V6 (ie. BMW 3-series use inline 6).
 

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ya i bolded the important stuff.. heh
if your talking about inline vs straight configuration
I would think a V format is better..
then again, indy, f1, cart, nascar, etc all use the v configuration
unless you mean just v6's
 

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I heard that the inline-6 configuration is one of the only configurations that's naturally balanced or something, that it doens't need counter-balancers to dampen engine vibration. Or somethign like that anyway....that's one of the advantages of inline-6, except that it's usually too big so they use V-6 if they want 6 cylinders, it's not as balanced but fits in a smaller space....
something like that anyway....
 

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Yeah, you got the point Naito. The I-6 is a balanced engine and can run smooth without balance shafts. I'd take an I-6 over an V6 any day, but many manufacteurers have gone from I to V, becuase you can make your cars more compact, since the V block is alot shorter than the I block.
 

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my impression was... there's the same... just diff configuration..
and also.. the balance.. but that would be very minor thing...
oh.. i thought boxer is more stable than inline... @@
 

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93 Z24 and 78 Bronco
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V6 just gives slightly better response and acceleration

but a I6 give out so much torque compared to a V6 that it'll kill anything off the line

i used to race my dad's 93 volvo 960 wagon against a lot of shit and smoked them huge, including 3rd gen camry's v6's (which is what i drive now)

this wagon'll do over 230, that's how far i pushed it and it wanted to keep going, but with rubber only rated to 170 (around there)
 

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in an inline engine, you also have a lot less wear than a V configuration. All your motion is going in two directions, not four and thus bearing loads are generally smaller and the engine will last longer.

The only truly ballanced engine though, is a boxer. With an inline engine, you still need crankshaft counterweights to act against the inertia of the pistons. With a boxer engine however, the crank can be counterweight free, as the pistons inherintly balance themselves with their sideways motion.

when it all comes down to it though, it all depends on the manufacturer. Look at Chryslers 2.2L and 2.5L fours from the Daytonas. Its an inline motor, but was so terribly designed that it needed 2 ballance shafts to keep it from shaking apart. Even then, it was a rough motor. Compare that to the 4AG and SR20DE and you'll see they have no balance shafts at all. They are just a better, more carfully designed engine.

Cheers,

Aaron
 

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Oldman said:
V6 just gives slightly better response and acceleration

but a I6 give out so much torque compared to a V6 that it'll kill anything off the line

i used to race my dad's 93 volvo 960 wagon against a lot of sh*t and smoked them huge, including 3rd gen camry's v6's (which is what i drive now)

this wagon'll do over 230, that's how far i pushed it and it wanted to keep going, but with rubber only rated to 170 (around there)
Yup, since the "I" config. pushes down, gives it more torque. Then the "V" config. that pushes at an angle, thus loosing torque. One good example of a an Inline-Sixer is the Supra (MKIV) the engine is virtually bulet proof. Capable of handeling horsepower in upwards of 800-900 on stock internals, and is capable of very high-milage.
 

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does anyone know if a 1990 Volvo GLE 760 is I6 or V6?
all i know is 760 has 6cyc...
 

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93 Z24 and 78 Bronco
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i know that the 86 760 was v6, but there was a big change around 1990 (front grill) maybe the engine too, not sure, now i`m interested though, i`ll have to have a look

edit: 89 760 has a 2.8 v6

re-edit: 90 had a v6 as well
 

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From what I remember, I6's vibrate less which means better response and less wear on the engine. And yes, it does mean better balance for the internals also.

V's are nice because they take up less room than a I6, but I'd still take reliability over everything. I mean, look at a MK4 Supra and the ole' 240Z's? The 240 doesn't make monster power gains but damn is it a potent lil' machine on the circuit.
 

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Another consideration is the degrees of crank rotation between power stroke on a 4-stroke engine. Remember that you havew 2 complete revolutions of crank rotation before all cylinders fire (720 degrees). On an inline six you have a power stroke every 120 degrees. With a 90 degree 'V' configuration you add & subtract 45 degrees off center. If you remember the early Buick V6 then you know how rough they run. When GM decided to not be cheap and actually design separate crankpins for each individual cylinder instead of sharing between 2 cylinders, they morphed into the 'even-firing' V6 on which the current Gen II 3800 is based.
On a four you have firing pulses ever 180 degrees, that is to say that the TDC cylinder fires at the same time an opposing piston reaches BDC. Fours as a result tend to have a 'vibration period' naturally occuring at 4000 rpm and again at 8000 rpm.
Anyway I wish I could explain it better but it made perfect sense when I learned it.
 

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300ZX twin turbo had more hp in stock form than both these cars and employed a 3L V6 engine to accomplish the fact. Whether it is a 'supercar' is debateable.

F1 Chris said:
trueno92 said:
the new z car is the first japanese'supercar' to use a v-anything engine.
the NSX has always had a V6
 

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Tailgating You
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I would say that the new Z and the old ZX are in the same league...GT cars...same with the Supra and the RX7.

NSX is a GT car with an exotic price...only 270hp? Pathetic.

911 Porsche would be approaching exotic level...but not quite...exotic yet...

A 360...Carrera GT...Merceilago...drooling yet?
 

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Cylinder configuration has very little to do with how much torque an engine produces (with a fixed displacement). Whether it's V6, I-6 or Flat-6, engines with the same rod/stroke and bore/stroke will have a very similar powerband regardless of the configuration. It's the rod/stroke that affects torque output as well as where the torque comes in the rev range. Engines with shorter rods and longer stroke (low R/S ratio) generally produces more torque especially at lower RPM's; however, high RPM power/torque suffers with a long stroke and short rod engine (like an SUV engine). Engines with very long rod and short stroke will make very little low-end torque, but it would take RPM's like nothing and make power up in high RPM's (ie: Hondas).

I-6 engines are known to be more "performance-bred" because of the exhaust harmonics that can be achieved with one exhaust header. In a V-engine, the firing order is not the "desired" pattern for exhaust harmonics unlike an inline engine which has an ideal firing order to achieve good exhaust efficiency. Of course, that's just one of the examples because there are much much more that comes into play as far as making an engine run well. I'd say any configuration is just as good.

As for the extra loads on the V-engines, the wear is negligable because the piston rings float inside the cylinders anyway. The rings always move around, so there isn't any "fixed" wear on the rings that would cause a much faster rate of wear and tear.
 
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