I6s are harder to get even air distribution. Most older designs had the outer runners much longer than the inner runners so each cylinder was "tuned" a little different. Some of the newer designs are much better. I've heard there is more crankshaft flex but I've never built an I6 so I can't comment. The I6 does have more main bearings though. All things being equal I would take an I6 over the V6 but it's kind of hard to do in a FWD configuration.
Observations regarding NA I4 vs V6 engines
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v4's were made! i just remembered this. my german made linde forklift has a v4 ford engine in it.
never seen a v4 before i got this forklift.
never seen a v4 before i got this forklift.
To compare a V6 to an I6 is worthless. There are a lot of V6's out there and hardly any I6's. Also as stated there are many V6 models out there that offer a similar model with an I4. If you are like me and do all your own maintenance most of the V6 models will scare you away. Some of the regular maintenance on V6 cars is beyond acceptable.
Originally Posted By: BarkerMan
To compare a V6 to an I6 is worthless. There are a lot of V6's out there and hardly any I6's. Also as stated there are many V6 models out there that offer a similar model with an I4. If you are like me and do all your own maintenance most of the V6 models will scare you away. Some of the regular maintenance on V6 cars is beyond acceptable.
What in particular are you talking about? I can think of a couple FWD setups that made me feel sorry for the poor guy that had to change the plugs on the firewall side. My TL looked difficult but proved to be a 30 minute job.
To compare a V6 to an I6 is worthless. There are a lot of V6's out there and hardly any I6's. Also as stated there are many V6 models out there that offer a similar model with an I4. If you are like me and do all your own maintenance most of the V6 models will scare you away. Some of the regular maintenance on V6 cars is beyond acceptable.
What in particular are you talking about? I can think of a couple FWD setups that made me feel sorry for the poor guy that had to change the plugs on the firewall side. My TL looked difficult but proved to be a 30 minute job.
Originally Posted By: Bror Jace
Question is, why are I6s smoother than V6s?
They're saying the firing frequencies of an inline six are evenly spaced; but by comparison, the firing frequencies of a V-6 are not evenly spaced.
My Buick 3800 V6 is pretty smooth, but it does have a rotating counterbalance shaft and is mounted on hydraulic engine mounts.
Canadian Driver
Question is, why are I6s smoother than V6s?
They're saying the firing frequencies of an inline six are evenly spaced; but by comparison, the firing frequencies of a V-6 are not evenly spaced.
My Buick 3800 V6 is pretty smooth, but it does have a rotating counterbalance shaft and is mounted on hydraulic engine mounts.
Canadian Driver
V6 vs I6 is a weight and packaging battle. The inline 6 is longer, too long to fit under the hood of a FWD car along with a transaxle, and the block and head weigh more as well. A V6 crank is little more than half the length of an I6 crank.
An inline 6 is inherently balanced because it's crank throws are 120 degrees apart so piston motion is cancelled out, same for a V12. This assumes the crank shaft 1&6,2&5,3&4 throws are in the same plane.
V4s are used when you have a packaging problem. They are unbalanced to the point where I don't know if a balance shaft can smooth all of the piston and rocking motions inherent to the design.
An inline 6 is inherently balanced because it's crank throws are 120 degrees apart so piston motion is cancelled out, same for a V12. This assumes the crank shaft 1&6,2&5,3&4 throws are in the same plane.
V4s are used when you have a packaging problem. They are unbalanced to the point where I don't know if a balance shaft can smooth all of the piston and rocking motions inherent to the design.
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Originally Posted By: Master ACiD
v4's were made! i just remembered this. my german made linde forklift has a v4 ford engine in it.
never seen a v4 before i got this forklift.
What about Subaru? Very common use of a "flat" V-4. Several motorcycles also use a V-4 setup.
v4's were made! i just remembered this. my german made linde forklift has a v4 ford engine in it.
never seen a v4 before i got this forklift.
What about Subaru? Very common use of a "flat" V-4. Several motorcycles also use a V-4 setup.
Originally Posted By: punisher
V4s are used when you have a packaging problem. They are unbalanced to the point where I don't know if a balance shaft can smooth all of the piston and rocking motions inherent to the design.
Interesting that my three year old daughter, upon being in a Subaru at startup for the first time, remarked: this car rocks side to side at first, doesn't it? It really does! Of course, it's just for a moment, then, it's very smooth, although a little noisy...which I don't mind.
V4s are used when you have a packaging problem. They are unbalanced to the point where I don't know if a balance shaft can smooth all of the piston and rocking motions inherent to the design.
Interesting that my three year old daughter, upon being in a Subaru at startup for the first time, remarked: this car rocks side to side at first, doesn't it? It really does! Of course, it's just for a moment, then, it's very smooth, although a little noisy...which I don't mind.
Originally Posted By: rationull
Originally Posted By: ShiningArcanine
From what I have read, I have come to believe that V6 engines have technological advantages over I6 engines ...
This piqued my interest. What technological advantages are you citing here? An I6 has more main bearings, and is much better balanced than a V6. It only has one cylinder head (and one head gasket), only requires one set of cams (assuming OHC), and can use a shorter timing chain (again, assuming OHC).
The only technical disadvantages I can see are that a longer head, cam, and crankshaft might be more prone to warpage or breaking but it doesn't seem like that's been a huge problem historically.
As stated above, clearly the V6 has great packaging advantages, but I'm curious as to what technological advantages you see here.
I had been under the impression from what I had read online more than a year ago that V engines gave better performance than equivalent inline engines. I had also been under the impression that smaller engines give lower performance and as an engine becomes smaller, the fuel economy increases. Therefore it seemed logical that a V engine could give better fuel economy than an inline engine while delievering the same horsepower. To me, that makes it technologically superior.
Originally Posted By: BarkerMan
To compare a V6 to an I6 is worthless. There are a lot of V6's out there and hardly any I6's. Also as stated there are many V6 models out there that offer a similar model with an I4. If you are like me and do all your own maintenance most of the V6 models will scare you away. Some of the regular maintenance on V6 cars is beyond acceptable.
I am working on a Biochemistry/Computer Science Double Major Chemistry/Mathematics Double Minor. On computer review sites, they do apples to apples comparisons with only one factor changing. Scientific experiments strive to minimize all differences between the control and experiment such that the only thing that varies is the variable that is being studied.
As far as what is technological advantageous is concerned, a I4 to V6 comparison cannot yield any information that would enable you to form a table where you can claim two directions to be superior on some basis and the opposite directions to be inferior on the same basis. An example of this is the periodic table in terms of electronegativity, where generally speaking, moving left and/or up across the table yields atoms of higher electronegativity and moving right and/or down across table yields atoms of lower electronegativity.
By the way, I think that when considering conventional automotive technologies, a V4 engine is optimal. I am not an mechanical engineer, but I imagine that a V4 engine could be placed with the V facing the front and back of the car rather than the sides as my Toyota Avalon's V6 engine faces. Doing that should allow easy access to all of the spark plugs and manifolds, making spark plug changes much easier than they are in my Avalon (which needs to be brought to the dealership for them) and placing both of the manifolds within access, rather than just one.
Originally Posted By: ShiningArcanine
From what I have read, I have come to believe that V6 engines have technological advantages over I6 engines ...
This piqued my interest. What technological advantages are you citing here? An I6 has more main bearings, and is much better balanced than a V6. It only has one cylinder head (and one head gasket), only requires one set of cams (assuming OHC), and can use a shorter timing chain (again, assuming OHC).
The only technical disadvantages I can see are that a longer head, cam, and crankshaft might be more prone to warpage or breaking but it doesn't seem like that's been a huge problem historically.
As stated above, clearly the V6 has great packaging advantages, but I'm curious as to what technological advantages you see here.
I had been under the impression from what I had read online more than a year ago that V engines gave better performance than equivalent inline engines. I had also been under the impression that smaller engines give lower performance and as an engine becomes smaller, the fuel economy increases. Therefore it seemed logical that a V engine could give better fuel economy than an inline engine while delievering the same horsepower. To me, that makes it technologically superior.
Originally Posted By: BarkerMan
To compare a V6 to an I6 is worthless. There are a lot of V6's out there and hardly any I6's. Also as stated there are many V6 models out there that offer a similar model with an I4. If you are like me and do all your own maintenance most of the V6 models will scare you away. Some of the regular maintenance on V6 cars is beyond acceptable.
I am working on a Biochemistry/Computer Science Double Major Chemistry/Mathematics Double Minor. On computer review sites, they do apples to apples comparisons with only one factor changing. Scientific experiments strive to minimize all differences between the control and experiment such that the only thing that varies is the variable that is being studied.
As far as what is technological advantageous is concerned, a I4 to V6 comparison cannot yield any information that would enable you to form a table where you can claim two directions to be superior on some basis and the opposite directions to be inferior on the same basis. An example of this is the periodic table in terms of electronegativity, where generally speaking, moving left and/or up across the table yields atoms of higher electronegativity and moving right and/or down across table yields atoms of lower electronegativity.
By the way, I think that when considering conventional automotive technologies, a V4 engine is optimal. I am not an mechanical engineer, but I imagine that a V4 engine could be placed with the V facing the front and back of the car rather than the sides as my Toyota Avalon's V6 engine faces. Doing that should allow easy access to all of the spark plugs and manifolds, making spark plug changes much easier than they are in my Avalon (which needs to be brought to the dealership for them) and placing both of the manifolds within access, rather than just one.
I understand your logic now. I had always heard that I6s would tend to get better fuel economy than V6s, although it does seem that performance and fuel economy concerns have more to do with displacement and engine management/other technologies than with configuration.
FWIW I agree with you that while the comparison isn't a terribly scientific one, it is a worthwhile one (and kinda fun to discuss
)
Also, V6s are placed longitudinally, as opposed to transversely all the time. Just not usually in FWD configurations. This is one reason why in general RWD cars are easier to maintain (barring things like newer cars having tons of stuff under the hood while older cars, even FWD ones, give you more room to work).
FWIW I agree with you that while the comparison isn't a terribly scientific one, it is a worthwhile one (and kinda fun to discuss
Also, V6s are placed longitudinally, as opposed to transversely all the time. Just not usually in FWD configurations. This is one reason why in general RWD cars are easier to maintain (barring things like newer cars having tons of stuff under the hood while older cars, even FWD ones, give you more room to work).
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Try your chart again after you do the same service work on both an I4 and a V6. Try a timing belt or changing the spark plugs yourself and you will begin to see a difference. Front plugs on a V6 in a transverse engine are easy enough but try the rear plugs. But all this is only a concern for the diy owner that keeps his car past the payments or lease. Otherwise just pay a mechanic and don't bother with it all.
A V6 is an exercise in excellence in engineering. Without a computer to help you design such an engine it would never become a successful commercial enterprise. It is strictly an answer to the question how do we get the most power and torque possible without a turbo or blower in this small space at the front end of an automobile. Without that question to work with you would never see such a package developed to the state of the current offerings on the market today. If you told a group of engineers in 1950 that you could design an engine that would develop 200+ horse power and fit in an opening the size of a Honda Accord engine compartment and get 20+ mpg and go 100k miles without oil changes and not much else they would laugh at you. Today that's the least an owner expects.
A V6 is an exercise in excellence in engineering. Without a computer to help you design such an engine it would never become a successful commercial enterprise. It is strictly an answer to the question how do we get the most power and torque possible without a turbo or blower in this small space at the front end of an automobile. Without that question to work with you would never see such a package developed to the state of the current offerings on the market today. If you told a group of engineers in 1950 that you could design an engine that would develop 200+ horse power and fit in an opening the size of a Honda Accord engine compartment and get 20+ mpg and go 100k miles without oil changes and not much else they would laugh at you. Today that's the least an owner expects.
Too bad more I4 engines are not turbo'd or blown. A blower on a small I4 would fatten the torque curve down low, allowing it to keep up with a larger-engined car while still getting better fuel economy. Same with a small turbo that could be tuned to boost maximally at the RPM's most people are routinely driving at.
How about the narrow angle V-6 in the VW engine family? Sort of a "tweener" between an inline 6 and the wider V engines.
I THINK this VW engine is at something like 18 degrees...
I THINK this VW engine is at something like 18 degrees...
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The VR6 sounds like a staggered-bore inline-6 too me.
http://en.wikipedia.org/wiki/VR6_engine
http://en.wikipedia.org/wiki/VR6_engine
Originally Posted By: sciphi
Too bad more I4 engines are not turbo'd or blown. A blower on a small I4 would fatten the torque curve down low, allowing it to keep up with a larger-engined car while still getting better fuel economy. Same with a small turbo that could be tuned to boost maximally at the RPM's most people are routinely driving at.
To make a certain amount of hp requires a certain amount of fuel no matter how much displacement is producing it. Superchargers require engine power to drive so gas mileage is reduced right there alone. A turbo motor could get small engine economy when you're driving it easy and big engine power when driving it hard but when driving hard it will use as much gas as a big motor.
Too bad more I4 engines are not turbo'd or blown. A blower on a small I4 would fatten the torque curve down low, allowing it to keep up with a larger-engined car while still getting better fuel economy. Same with a small turbo that could be tuned to boost maximally at the RPM's most people are routinely driving at.
To make a certain amount of hp requires a certain amount of fuel no matter how much displacement is producing it. Superchargers require engine power to drive so gas mileage is reduced right there alone. A turbo motor could get small engine economy when you're driving it easy and big engine power when driving it hard but when driving hard it will use as much gas as a big motor.
Especially with the overly rich AFR's some turbo engines need to stay together with lotsa boost.
Any comments on...
Saab's low pressure turbo (Ecopower) or variable compression engines?
http://en.wikipedia.org/wiki/Saab_Variable_Compression_engine
http://www.saabnet.com/tsn/models/1999/9995pr5.html
Nissan L28E vs VG30E? I-6 vs V6.
V-4 vs I-4?
Any comments on...
Saab's low pressure turbo (Ecopower) or variable compression engines?
http://en.wikipedia.org/wiki/Saab_Variable_Compression_engine
http://www.saabnet.com/tsn/models/1999/9995pr5.html
Nissan L28E vs VG30E? I-6 vs V6.
V-4 vs I-4?
Sure! Staggered is a term that makes sense. And, it's 10.8 to 15 degrees of offset (I guess due to different engines produced at different times), not 18 (like I erroneously suggested). Anyway, I used to have one, and it ran like a champ...good economy, too. They do tend to run a little on the hot side, but, they are a good "tweener" engine; more cylinders than a 4, not exactly an inline, not exactly a V, not as short as a V, but more narrow. I liked it.
Originally Posted By: Titan
What about Subaru? Very common use of a "flat" V-4. Several motorcycles also use a V-4 setup.
Don't know what a "flat" V-4" is. It is either a flat (boxer) or a "V", not both.
What about Subaru? Very common use of a "flat" V-4. Several motorcycles also use a V-4 setup.
Don't know what a "flat" V-4" is. It is either a flat (boxer) or a "V", not both.
Originally Posted By: punisher
Don't know what a "flat" V-4" is. It is either a flat (boxer) or a "V", not both.
That would be a 180 degree V.
Don't know what a "flat" V-4" is. It is either a flat (boxer) or a "V", not both.
That would be a 180 degree V.
Originally Posted By: XS650
Originally Posted By: punisher
Don't know what a "flat" V-4" is. It is either a flat (boxer) or a "V", not both.
That would be a 180 degree V.
You're being obtuse now.
Originally Posted By: punisher
Don't know what a "flat" V-4" is. It is either a flat (boxer) or a "V", not both.
That would be a 180 degree V.
You're being obtuse now.
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