What's the difference between a V6 and and normal engine?
Discussion
I'm going to get labelled a n00b here but I've been looking at cars on trader for ages including the tech specs and stuff but cannot really see a lot of difference in speed between for instance a BMW 3 series 330 "straight 6" or a Jag X type 3.0 V6. In fact the straight 6 seems better.
So what's all the hype with V6's or indeed V8 and V12... although I've never heard of a Straight 8 or 12. Some V6 engines seem pathetic as well eg the Hyundai V6 Coupe.
So what's all the hype with V6's or indeed V8 and V12... although I've never heard of a Straight 8 or 12. Some V6 engines seem pathetic as well eg the Hyundai V6 Coupe.
Lots of info here:
http://auto.howstuffworks.com/engine9.htm
There are certainly Straight 8 engines around, very old ones though. V engines are inherently smoother than straight engines because they are better balanced, with the exception of the Straight 6 (BMW being the biggest manufacturer of these) which is inherently well balanced.
http://auto.howstuffworks.com/engine9.htm
There are certainly Straight 8 engines around, very old ones though. V engines are inherently smoother than straight engines because they are better balanced, with the exception of the Straight 6 (BMW being the biggest manufacturer of these) which is inherently well balanced.
Balmoral Green said:
tomTVR said:
If they make a straight 12 then sign me up.
Wärtsilä-Sulzer RTA96-CWouldn't normally go to Wikipedia for "facts" but those are some big numbers
Edited by Mark-C on Tuesday 18th November 19:30
Edited by Mark-C on Tuesday 18th November 19:31
Mark-C said:
Balmoral Green said:
tomTVR said:
If they make a straight 12 then sign me up.
Wärtsilä-Sulzer RTA96-CWouldn't normally go to Wikipedia for "facts" but those are some big numbers
Essentially its the 'shape' of the engine. Most engines in mainstream cars are an in-line four, or straight four, i.e four cylinders in a row. I can't think of a current V4 but they exist and are popular in the biking world as well. They are essentially two pairs of cylinders opposite each other, rather than four in a line. So a V6 vs. straight 6 is the same, either 6 in a line or 2 pairs of three opposite each other. A straight six 'should' be smoother but is obviously 6 cylinders long and so is a very long engine. A V6 is only 3 cylinders long but is wider that a straight 6. Generally speaking, a V6 will be more compact. There should be no real reason why one configuration should be more powerful than another though they sound subtly different.
ETA, should have said that the V refers to the fact that the cylinder banks are leant over in relation to each other. Simplistically, if they're banked over at 180 degrees, you have a flat engine or a 'boxer' engine.
ETA, should have said that the V refers to the fact that the cylinder banks are leant over in relation to each other. Simplistically, if they're banked over at 180 degrees, you have a flat engine or a 'boxer' engine.
Edited by Gad-Westy on Tuesday 18th November 19:36
wildoliver said:
miniman said:
V engines are inherently smoother than straight engines because they are better balanced
Total rubbish. Couldn't be more wrong. Straight engines are the smoothest V engines are inherently out of balance.I owned a BMW 328 straight 6 then went onto a vectra GSI which is a 2.5 V6. I know the BMW was slightly bigger but it felt like it had a lot more low end torque and i think this is a generic trait of the "straight" engine. They are also really smooth as the firing sequence is very close so one piston fires very soon after the last in laymans terms.
I'm sure those links will explain it better but thought i'd comment as i've owned both.
(also owned a Range rover V8 but we won't go there ......ever again
)
I'm sure those links will explain it better but thought i'd comment as i've owned both.
(also owned a Range rover V8 but we won't go there ......ever again
)Gad-Westy said:
Essentially its the 'shape' of the engine. Most engines in mainstream cars are an in-line four, or straight four, i.e four cylinders in a row. I can't think of a current V4 but they exist and are popular in the biking world as well. They are essentially two pairs of cylinders opposite each other, rather than four in a line. So a V6 vs. straight 6 is the same, either 6 in a line or 2 pairs of three opposite each other. A straight six 'should' be smoother but is obviously 6 cylinders long and so is a very long engine. A V6 is only 3 cylinders long but is wider that a straight 6. Generally speaking, a V6 will be more compact. There should be no real reason why one configuration should be more powerful than another though they sound subtly different.
Well put Sir!G
wildoliver said:
miniman said:
V engines are inherently smoother than straight engines because they are better balanced
Total rubbish. Couldn't be more wrong. Straight engines are the smoothest V engines are inherently out of balance.No thought has gone into this question ... it's just gut feel .... and obviously a radial isn't much use in a car, although I bet some nutter genius in a shed has done it.
wildoliver said:
miniman said:
V engines are inherently smoother than straight engines because they are better balanced
Total rubbish. Couldn't be more wrong. Straight engines are the smoothest V engines are inherently out of balance.Admittedly this is just Wikipedia but if you like I'll dig out something more "credible"
http://en.wikipedia.org/wiki/Engine_balance
wikipedia said:
More than two cylinders
The number of possible configurations with more than two cylinders is enormous. See articles on individual configurations listed in Category:Piston engine configurations for detailed discussions of particular configurations.
There are four different forces and moments of vibration that can occur in an engine design: free forces of the first order, free forces of the second order, free moments of the first order, and free moments of the second order. The straight-6, flat-6, and V12 designs have none of these forces or moments of vibration, and hence are the naturally smoothest engine designs. (See the Bosch Automotive Handbook, Sixth Edition, pages 459-463 for details.)
Engines with particular balance advantages include:
* Straight-6
* Flat-6
* Flat-12
* V12
Engines with characteristic problems include:
* Flat-4 boxer and straight-4 have no better kinetic energy balance than a single, and require a relatively large flywheel.
* Crossplane V8, which requires a very heavily weighted crankshaft, and has unbalanced firing between the cylinder banks (producing the distinctive and much-loved V8 "burble").
* Flatplane (180° offset crankshaft) V8.
In modern multi-cylinder engines, many inherent balance problems are addressed by use of balance shafts. Tear is reduced only when the crankshaft is partly balanced before it touches any bearing as it is done in the flat and the V-engines. A balancer shaft transfers its force via bearings onto the crankshaft and rather increases tear.
The number of possible configurations with more than two cylinders is enormous. See articles on individual configurations listed in Category:Piston engine configurations for detailed discussions of particular configurations.
There are four different forces and moments of vibration that can occur in an engine design: free forces of the first order, free forces of the second order, free moments of the first order, and free moments of the second order. The straight-6, flat-6, and V12 designs have none of these forces or moments of vibration, and hence are the naturally smoothest engine designs. (See the Bosch Automotive Handbook, Sixth Edition, pages 459-463 for details.)
Engines with particular balance advantages include:
* Straight-6
* Flat-6
* Flat-12
* V12
Engines with characteristic problems include:
* Flat-4 boxer and straight-4 have no better kinetic energy balance than a single, and require a relatively large flywheel.
* Crossplane V8, which requires a very heavily weighted crankshaft, and has unbalanced firing between the cylinder banks (producing the distinctive and much-loved V8 "burble").
* Flatplane (180° offset crankshaft) V8.
In modern multi-cylinder engines, many inherent balance problems are addressed by use of balance shafts. Tear is reduced only when the crankshaft is partly balanced before it touches any bearing as it is done in the flat and the V-engines. A balancer shaft transfers its force via bearings onto the crankshaft and rather increases tear.
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