Fullauto Cylinder Head
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As a kid we built an expansion chamber from the formulas.
Couldn't tell it made much difference, but it did sound the business. !
Hotrodding lawnmower engines for karts may have limited saleability though...
The genuine article are pretty highly tuned.
Some of these car driving entertainment thingies in pubs and arcades are pretty sophisticated,
when you look at them closely. Although the 1001 tweaks available to the real thing are mostly omitted.
Couldn't tell it made much difference, but it did sound the business. !
Hotrodding lawnmower engines for karts may have limited saleability though...
The genuine article are pretty highly tuned.
Some of these car driving entertainment thingies in pubs and arcades are pretty sophisticated,
when you look at them closely. Although the 1001 tweaks available to the real thing are mostly omitted.
splatt said:
First time I've ever totally agreed with you.
Something that was seriously able to sort all all the minor variables and variations would cost $squillions$,
and who would tweak it for an obsolete old Commando...
Heck, Harley don't even do their own engine design work.
Rohan said:
You can't actually take a building for a test fly, or a test ride, or try it in a wind tunnel, so the simulation is all they can do with it.
Anyone familiar with this stuff will know of the (skyscraper) building they built - in NY was it ? - with one support missing, as a design feature. Until one of the students ran a better simulation, and proved that it could fail if the wind was from the wrong direction and strong enough. One hasty added construction later, it has an extra leg....
We diverge from FA heads, a little.
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Rohan said:
Sorry but Dream Works is an animation software, not a simulation software; but splatt nailed it on the second part :lol:
Rohan said:
The real Walter Mitty has stood up! This from someone who appears to not have a clue about systems simulations, numerical modeling and all. As an example, Jim C. uses an engine simulation system "for an obsolete old Commando" to find effective ways to make it not so obsolete
and it does not cost "$squillions$". I would say Virtual 4 - Stroke would handle most if not all the pertinent "minor variables and variations" without a problem for a very minor fraction of $squillions$ but the reality is you probably don't need it if you know what you are doing.A very inexpensive and half way decent package is Desktop Dyno5. The efficiency of these packages is being able to test incremental changes once the model is benchmarked. Not rocket science. The most tedious work is collecting the data to feed into the system. So you benchmark the simulation to say a stock 850, 750 or Combat Commando, whatever you want, enter the attributes of the new Full Auto head, rerun the simulation and voila! (or your brother is your Uncle), you get a pretty good idea of net change.
Irony is lost on you.....
So if Desktop Dyno says a FullAuto head will produce 100 hp on a Commando, will we believe it ??
What did Jims theory say his FA design was good for ?
I have a head with a flat just before the inlet guide.
How does that factor into a simulation. ?
Without actually testing it like that, no package would be aware that it is quite beneficial ...
Comparing that 4 cyl head to the race one I showed earlier would be seriously 'tedious'.
How accurate would the comparo be, we wonder....
https://s31.postimg.org/6h4kkx8kr/heads.jpg
So if Desktop Dyno says a FullAuto head will produce 100 hp on a Commando, will we believe it ??
What did Jims theory say his FA design was good for ?
I have a head with a flat just before the inlet guide.
How does that factor into a simulation. ?
Without actually testing it like that, no package would be aware that it is quite beneficial ...
Comparing that 4 cyl head to the race one I showed earlier would be seriously 'tedious'.
How accurate would the comparo be, we wonder....
https://s31.postimg.org/6h4kkx8kr/heads.jpg
Dances with Shrapnel said:
Hmmmm
"I recently wasted my money on the crummy "Dyno 5 Sim" & "Desktop Dyno 5" software, and it isn't even close to being accurate."
http://www.chevelles.com/forums/13-perf ... tware.html
"I recently wasted my money on the crummy "Dyno 5 Sim" & "Desktop Dyno 5" software, and it isn't even close to being accurate."
http://www.chevelles.com/forums/13-perf ... tware.html
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Clear case of projection yet over the top. 8)Rohan said:
Reread my posts, particularly about benchmarking, especially with simpler software packages. I suppose Virtual 4-Stroke with a FLUENT CFD of ports will answer all the irrelevant what-if minutiae you can rapid fire but that is not the point.Rohan said:
The nature of your question(s) indicate you do not understand nor are you here to understand. Start a new thread if you are serious.
Your comments prove you haven't actually done anything serious with this stuff.
I've had a great deal to do with computers and their uses - we sold shedloads of them, and saw them in action in all sorts of applications. Some of those applications cost $millions$, and we were very privileged to see some of them in action - architecture stuff in particular, thats where the $$$ commonly are - unless you are in aerospace I guess.
Engine design is not one of the more reliable uses I can think of, the simulations need (serious) dyno time to verify them, and find correction factors that can be applied to get them anywhere remotely near accurate.
So whats the point of the simulations if the dyno time isn't reduced ??
Not far from me is a top car race teams workshops. You can do the tour, although they probably don't show too much secret stuff. EVERYTHING is computer designed, but they do a mighty lot of testing....
I've had a great deal to do with computers and their uses - we sold shedloads of them, and saw them in action in all sorts of applications. Some of those applications cost $millions$, and we were very privileged to see some of them in action - architecture stuff in particular, thats where the $$$ commonly are - unless you are in aerospace I guess.
Engine design is not one of the more reliable uses I can think of, the simulations need (serious) dyno time to verify them, and find correction factors that can be applied to get them anywhere remotely near accurate.
So whats the point of the simulations if the dyno time isn't reduced ??
Not far from me is a top car race teams workshops. You can do the tour, although they probably don't show too much secret stuff. EVERYTHING is computer designed, but they do a mighty lot of testing....
P.S. If you want to play comparo with engine designs, call up the Commando 750/850 specs as against the GT750 Laverda and Yam TDM850. On paper, these are all quite similar designs, when you just look at the numbers.
And all parallel twins too,
Be a good simulation package that could accurately differentiate those, and successfully predict engine outputs ?
And, if you throw a bevel drive Duc into the equation, even with their smaller valves and v-angle, they are similar too in many ways.
Until you throw the desmo and SFC versions into the mix.
http://i.ebayimg.com/00/s/MTE5NFgxNjAw/ ... D/$_57.JPG
The color scheme remind you of anything in a Commando lineup ?
We diverge, it hasn't quite got a FA head on it...
And all parallel twins too,
Be a good simulation package that could accurately differentiate those, and successfully predict engine outputs ?
And, if you throw a bevel drive Duc into the equation, even with their smaller valves and v-angle, they are similar too in many ways.
Until you throw the desmo and SFC versions into the mix.
http://i.ebayimg.com/00/s/MTE5NFgxNjAw/ ... D/$_57.JPG
The color scheme remind you of anything in a Commando lineup ?
We diverge, it hasn't quite got a FA head on it...
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Selling shed loads? Burroughs computers?
You can get a lot done with today's laptops. Utilizing a CFD like FLUENT will take a bit more to be efficient but let's face it, that is really over the top for the original inquiry. It can be answered with a PC based software, you just need to know what you are doing.
Ultimately you need a torque/power curve for your presumably stock test bike but that data is out there. You need valve flow coefficients for a stock head at various lifts and that data is out there. Same data is needed for the FullAuto head and I am reasonably sure that data is out there. You also need valve lift by crank angle and that data is out there.
I've done a few successful engine simulations (not made a career out of it) and worked closely with Gordon Blair when he helped us with the 500 Norton simulation and cam design. I've personally done many other stochastic simulations and worked with a national laboratory in support of the mother of all simulations. You need to understand it.
You can get a lot done with today's laptops. Utilizing a CFD like FLUENT will take a bit more to be efficient but let's face it, that is really over the top for the original inquiry. It can be answered with a PC based software, you just need to know what you are doing.
Ultimately you need a torque/power curve for your presumably stock test bike but that data is out there. You need valve flow coefficients for a stock head at various lifts and that data is out there. Same data is needed for the FullAuto head and I am reasonably sure that data is out there. You also need valve lift by crank angle and that data is out there.
I've done a few successful engine simulations (not made a career out of it) and worked closely with Gordon Blair when he helped us with the 500 Norton simulation and cam design. I've personally done many other stochastic simulations and worked with a national laboratory in support of the mother of all simulations. You need to understand it.
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Rohan said:
Your questions are showing you don't understand. Key in on the term benchmark. You cannot benchmark a model to a Laverda and then use that model to see how a Commando will respond to a change - that is being silly.
Dances with Shrapnel said:
Most of it is intuitive - if you understand engines.
It takes someone with that knowledge to program it in the first place....
But that level of detail is simply not detailed enough to show slight changes anywhere.
e.g. does lightening the rocker gear help or hinder ??
Does opening the throat out help or hinder.
Does lengthening the throat help or hinder ?
Impressive with Dr Blair.
That would have been a while ago.
Puters were awfully basic back then....
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"Presumably"?.......Then: ........."we are way ahead of you here"
Funny, yes, but you are now understanding. Where's the humility?
Funny, yes, but you are now understanding. Where's the humility?
My understanding of this stuff goes back decades.
Many decades.
Its a few decades now since I was seriously involved with computers, doesn't time fly..
Prof Gordon Blair was all the rage in the 1970s.
Although all he did, and I don't want to trivilize this, is to apply sound mathematics to what
had previously been a black art...
Many decades.
Its a few decades now since I was seriously involved with computers, doesn't time fly..
Prof Gordon Blair was all the rage in the 1970s.
Although all he did, and I don't want to trivilize this, is to apply sound mathematics to what
had previously been a black art...
@Jerry can you lock this thread please?
It's turned in to a real sh!t storm and really taints the forum with a nasty taste.
We're grown-ups and this kind of bitching is what I would expect to see on the Norton Owners Club Forum.
Please respect each other, we are all entitled to our own views and opinions but let's stop with the childish quips please.
Access is the BEST place for great information, sharing some wonderful knowledge and awesome banter.
Let's not wreck it.
It's turned in to a real sh!t storm and really taints the forum with a nasty taste.
We're grown-ups and this kind of bitching is what I would expect to see on the Norton Owners Club Forum.
Please respect each other, we are all entitled to our own views and opinions but let's stop with the childish quips please.
Access is the BEST place for great information, sharing some wonderful knowledge and awesome banter.
Let's not wreck it.
Its disappointing that its gone this way.
But surely the revelation that some of the many computer programs offered in
this field (and many others) aren't worth the $$ being charged for them.
Not to mention the dubious claims made for them....
As someone far wiser than any of us once said about computers, there is nothing they can do that can't be done on the back of an envelope - and some color pencils these days.
But surely the revelation that some of the many computer programs offered in
this field (and many others) aren't worth the $$ being charged for them.
Not to mention the dubious claims made for them....
As someone far wiser than any of us once said about computers, there is nothing they can do that can't be done on the back of an envelope - and some color pencils these days.
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