How is displacement is increased in F22c1?
06-17-2013, 08:27 PM
#11
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Originally Posted by vtec9' timestamp='1371477352' post='22613121
more stroke => fewer RPMs. But IIRC, the F22C actually has a higher piston speed at redline than F20C due to further distance traveled per rotation.
.Old engine speed * old stroke = new engine speed * new stroke
A little algebra and substitution gives us:
9000 rpm * (84.4 mm)/(90.7 mm) = 8375 rpm
06-17-2013, 10:56 PM
#12
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There is main - or average - piston speed.
And then there is real / true / whateveryouliketocallit - piston speed.
http://en.wikipedia....otion_equations
Rod length plays a role too, is there a difference between F20 and F22 rods? (I guess so)
Lots of formula's on that Wiki page, as far as I could see no easy, fill in stroke, rod lenght and rpm to give you speed formula, or graph.
The oil burning issues were solved for the F20 and F22 by honing with a dummy head.
So later MY F20's burn as much oil as F22's = 1 "advantage" gone.
(yes, Honda sold F20's till the end in - for example - Europe)
Honda used the other type retainers also in the F20, my MY05 F20 has them and as far as I know it was an untouched engine.
The original F20 retainers only get damaged if you treat them wrong, to call this an engine error is.... well...
Many will state their original F20 retainers, even at 9k-all-day-without-an-overrev, are still fine.
Later model F20's with "better" OEM installed retainers = 1 "advantage" gone.
To call the whole valve train superior because of the retainers is... well...
How many advantages left?
Yes, the debate is endless, especially if you (one) uses the wrong kind of arguments to support your (one's) claim.
And then there is real / true / whateveryouliketocallit - piston speed.
http://en.wikipedia....otion_equations
Rod length plays a role too, is there a difference between F20 and F22 rods? (I guess so)
Lots of formula's on that Wiki page, as far as I could see no easy, fill in stroke, rod lenght and rpm to give you speed formula, or graph.
The oil burning issues were solved for the F20 and F22 by honing with a dummy head.
So later MY F20's burn as much oil as F22's = 1 "advantage" gone.
(yes, Honda sold F20's till the end in - for example - Europe)
Honda used the other type retainers also in the F20, my MY05 F20 has them and as far as I know it was an untouched engine.
The original F20 retainers only get damaged if you treat them wrong, to call this an engine error is.... well...
Many will state their original F20 retainers, even at 9k-all-day-without-an-overrev, are still fine.
Later model F20's with "better" OEM installed retainers = 1 "advantage" gone.
To call the whole valve train superior because of the retainers is... well...
How many advantages left?
Yes, the debate is endless, especially if you (one) uses the wrong kind of arguments to support your (one's) claim.
06-18-2013, 07:28 AM
#13
Registered User
There is main - or average - piston speed.
And then there is real / true / whateveryouliketocallit - piston speed.
http://en.wikipedia....otion_equations
Rod length plays a role too, is there a difference between F20 and F22 rods? (I guess so)
Lots of formula's on that Wiki page, as far as I could see no easy, fill in stroke, rod lenght and rpm to give you speed formula, or graph.
The oil burning issues were solved for the F20 and F22 by honing with a dummy head.
So later MY F20's burn as much oil as F22's = 1 "advantage" gone.
(yes, Honda sold F20's till the end in - for example - Europe)
Honda used the other type retainers also in the F20, my MY05 F20 has them and as far as I know it was an untouched engine.
The original F20 retainers only get damaged if you treat them wrong, to call this an engine error is.... well...
Many will state their original F20 retainers, even at 9k-all-day-without-an-overrev, are still fine.
Later model F20's with "better" OEM installed retainers = 1 "advantage" gone.
To call the whole valve train superior because of the retainers is... well...
How many advantages left?
Yes, the debate is endless, especially if you (one) uses the wrong kind of arguments to support your (one's) claim.
And then there is real / true / whateveryouliketocallit - piston speed.
http://en.wikipedia....otion_equations
Rod length plays a role too, is there a difference between F20 and F22 rods? (I guess so)
Lots of formula's on that Wiki page, as far as I could see no easy, fill in stroke, rod lenght and rpm to give you speed formula, or graph.
The oil burning issues were solved for the F20 and F22 by honing with a dummy head.
So later MY F20's burn as much oil as F22's = 1 "advantage" gone.
(yes, Honda sold F20's till the end in - for example - Europe)
Honda used the other type retainers also in the F20, my MY05 F20 has them and as far as I know it was an untouched engine.
The original F20 retainers only get damaged if you treat them wrong, to call this an engine error is.... well...
Many will state their original F20 retainers, even at 9k-all-day-without-an-overrev, are still fine.
Later model F20's with "better" OEM installed retainers = 1 "advantage" gone.
To call the whole valve train superior because of the retainers is... well...
How many advantages left?
Yes, the debate is endless, especially if you (one) uses the wrong kind of arguments to support your (one's) claim.
Exactly my thoughts! All of those revisions mentioned were in the MY04+ F20c which we have in Europe.
06-18-2013, 04:47 PM
#15
Registered User
There is main - or average - piston speed.
And then there is real / true / whateveryouliketocallit - piston speed.
http://en.wikipedia....otion_equations
...
And then there is real / true / whateveryouliketocallit - piston speed.
http://en.wikipedia....otion_equations
...
Apparently I was wrong.
06-18-2013, 10:36 PM
#16
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@ dwight: I was simply - without any hidden agenda or any point to prove - adding (what I assumed was) usefull info to the thread.
I hoped that my post - or better: the link to the Wiki page - showed the true - from degree to degree or mathematically constantly changing - piston speed (and accelleration!) is slightly more complex than stroke and rpm - with an indefinitely long connecting rod it IS.. actually.
Allthough one could think adding the link was done to prove a point, but I didn't argue earlier that it was not that simple or stated someone was wrong, if you know what I mean.
More - even if its complex - info = always better, IMO.
I hoped that my post - or better: the link to the Wiki page - showed the true - from degree to degree or mathematically constantly changing - piston speed (and accelleration!) is slightly more complex than stroke and rpm - with an indefinitely long connecting rod it IS.. actually.
Allthough one could think adding the link was done to prove a point, but I didn't argue earlier that it was not that simple or stated someone was wrong, if you know what I mean.
More - even if its complex - info = always better, IMO.
06-19-2013, 09:24 AM
#17
Registered User
Not when it obfuscates the topic and discourages the reader from trying to understand the topic.
A lot of people don't understand mean piston speed. The math required to understand this isn't even basic algebra. It's just substitution and multiplication. This something that a middle school student can do.
Then, out of nowhere, you come in and start talking about something different, although tangentially related, which turns it into a dynamics problem which is typically taught as a sophomore level college problem. This can leave a reader with the impression that it's much more complicated and actually serve to discourage them from trying to understand the topic.
A lot of people don't understand mean piston speed. The math required to understand this isn't even basic algebra. It's just substitution and multiplication. This something that a middle school student can do.
Then, out of nowhere, you come in and start talking about something different, although tangentially related, which turns it into a dynamics problem which is typically taught as a sophomore level college problem. This can leave a reader with the impression that it's much more complicated and actually serve to discourage them from trying to understand the topic.
06-19-2013, 11:48 AM
#18
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Ohhh... okay.. so I should have preceded my post with a warning: "difficult stuff ahead.. beware!"
I think you're overdoing it... a little.. maybe.... and maybe you should have a bit more confidence in the average s2ki reader.
Lets make it simple: (and NOT for you so don't get offended.. again... allthough you could get offended by me saying its not for you.. oh well..)
Suppose you have to travel a certain - fixed - distance within a speed limit.
When you start you pass a detection port, setting your timer at 0.
At the end of the distance you pass another detection port which stops your timer.
(how this detection works is - for now - irrelevant, be sure there can be no mix-up between participants)
As soon as the time is known, the average speed is known because the distance is known, this is (should be) pretty simple to understand.
A computer calculates your average speed and decides if you should receive a speeding ticket.
How could the computer tell if you stopped somewhere for x time and have driven way above the speed limit to compensate for lost time?
It can't when it just looks at the end and the beginning.
That is exactly what you're doing with main / average piston speed.
In half a crank turn you travel the stroke distance, rpm and stroke are given so one's able to find the outcome with some (basic) math.
What happens in between is not in this equation.
But stuff DOES happen in between, that's a fact.
Hiding from the facts is not my thing, even if they are hard to understand.
I'm not claiming to fully understand all the formula's given on the Wiki page but I can see the constanly changing triangle creating complex motions.
So I can live with knowing I don't fully know.
Can you, do you allow others to do so or do you want to hide anything more complex than taking a dump from them...?
(apologies for the excremental references..)
What I do know is that main piston speed is just an average and not the complete picture and there is - way - more to it.
People that would like to take a look at the Wiki page are free to do so, and people are free to look and click it away within a blink of an eye too.
I think you're overdoing it... a little.. maybe.... and maybe you should have a bit more confidence in the average s2ki reader.
Lets make it simple: (and NOT for you so don't get offended.. again... allthough you could get offended by me saying its not for you.. oh well..)
Suppose you have to travel a certain - fixed - distance within a speed limit.
When you start you pass a detection port, setting your timer at 0.
At the end of the distance you pass another detection port which stops your timer.
(how this detection works is - for now - irrelevant, be sure there can be no mix-up between participants)
As soon as the time is known, the average speed is known because the distance is known, this is (should be) pretty simple to understand.
A computer calculates your average speed and decides if you should receive a speeding ticket.
How could the computer tell if you stopped somewhere for x time and have driven way above the speed limit to compensate for lost time?
It can't when it just looks at the end and the beginning.
That is exactly what you're doing with main / average piston speed.
In half a crank turn you travel the stroke distance, rpm and stroke are given so one's able to find the outcome with some (basic) math.
What happens in between is not in this equation.
But stuff DOES happen in between, that's a fact.
Hiding from the facts is not my thing, even if they are hard to understand.
I'm not claiming to fully understand all the formula's given on the Wiki page but I can see the constanly changing triangle creating complex motions.
So I can live with knowing I don't fully know.
Can you, do you allow others to do so or do you want to hide anything more complex than taking a dump from them...?
(apologies for the excremental references..)
What I do know is that main piston speed is just an average and not the complete picture and there is - way - more to it.
People that would like to take a look at the Wiki page are free to do so, and people are free to look and click it away within a blink of an eye too.
06-19-2013, 06:51 PM
#19
Sorry, but I have to agree with Dwight on this one.
The maximum piston speed is attained precisely when the piston is half way between TDC and BDC. At that point, the piston is traveling at the same speed as the rod bearing.
At 9000 rpm, the rod bearing is traveling at Π * D * 9000, where D is the crank diameter, which is the same as the piston stroke.
On the F20C, D = 84.4mm, and on the F22C, D = 90.7mm
Therefore, to calculate when the rod bearing speeds are equivalent, you use the equation:
Π * D[sub]f20c[/sub]*9000=Π * D[sub]f22c[/sub] * rpm[sub]f22c[/sub]
or
rpm[sub]f22c[/sub]= (Π * D[sub]f20c[/sub]*9000) / Π * D[sub]f22c[/sub]
remove Π from both the denominator and numerator, that leaves you with:
rpm[sub]f22c[/sub]= (84.4mm * 9000rpm) / 90.7mm, or 8375 RPM.
The maximum piston speed is attained precisely when the piston is half way between TDC and BDC. At that point, the piston is traveling at the same speed as the rod bearing.
At 9000 rpm, the rod bearing is traveling at Π * D * 9000, where D is the crank diameter, which is the same as the piston stroke.
On the F20C, D = 84.4mm, and on the F22C, D = 90.7mm
Therefore, to calculate when the rod bearing speeds are equivalent, you use the equation:
Π * D[sub]f20c[/sub]*9000=Π * D[sub]f22c[/sub] * rpm[sub]f22c[/sub]
or
rpm[sub]f22c[/sub]= (Π * D[sub]f20c[/sub]*9000) / Π * D[sub]f22c[/sub]
remove Π from both the denominator and numerator, that leaves you with:
rpm[sub]f22c[/sub]= (84.4mm * 9000rpm) / 90.7mm, or 8375 RPM.
06-19-2013, 10:07 PM
#20
Registered User
...
Lets make it simple: (and NOT for you so don't get offended.. again... allthough you could get offended by me saying its not for you.. oh well..)
...
That is exactly what you're doing with main / average piston speed.
...
But stuff DOES happen in between, that's a fact.
...
Lets make it simple: (and NOT for you so don't get offended.. again... allthough you could get offended by me saying its not for you.. oh well..)
...
That is exactly what you're doing with main / average piston speed.
...
But stuff DOES happen in between, that's a fact.
...
You don't need to explain average/mean to me. By the way if you want something with more detail you can read up on the mean value theorem.
That stuff doesn't matter. If one want to get into more detail for the sake of getting into detail, it's easy to lose sight of the problem/question. This all started when I responded to a post where two people didn't know what RPM provided the same mean piston speed. I tried to show them that it's really easy for them to calculate this themselves.