Rohan said:
You still seem stuck on a faux version of the real world ?
Not at all as Dyno data has its place. Engine simulation is just a better way to answer more questions and judging by your posts there are lots of questions????????? A dyno pull will give you data for one set of parameters only. You must physically change and modify the engine and ancillaries to find out how else it will behave. A lot of work. The reality is to work smarter, not harder. I seem to recall in this thread that you are keen on old school paper and pencil figure it out kinda stuff. Engine simulations (simple and complex) are deterministic numerical models (even when utilizing CFD). These models are a series of calculations that are precise and repeatable.
I recall that DeskTop Dyno 5 allows parametric analysis where it will run and generate a suite of curves (three-axis surface chart) based on varying one (maybe more) parameters such as compression ratio, intake tract length, exhaust length etc... A pretty powerful tool.
There are those here on record who are using or are about to use a FA head and a single carb set up will respond differently than a bone stock engine or a race engine with high-performance cam and say a Steve Maney exhaust and different carbs and intake tract length (different from stock). I am sure at least one person on this forum could probably rattle off a pretty good set of performance numbers from their head based on their vast and well-respected knowledge and first-hand experience with Norton cylinder head flow characteristics. So what is the answer to the question; well it really depends on the customer's application.
Rohan said:
OK, I'll admit I was (lightly) involved in an early version of engine simulation stuff, although it wasn't called that back then. It was pretty primitive too - as were computers back then.
Involved, like 35 years ago walking past someone in a hallway that does engine modelling for a living?
Rohan said:
Someone just now has recommended another package - which takes 2 weeks !!! to input enough parameters, measurements, and data before it can start chugging away. By eck....
Talk about faux. Did this "someone" meet you late at night in the basement of a Washington, DC parking garage? Was he speaking in a low tone and smoking a cigarette? Did you get a clear look at his face in the shadows? Un named package? I think this is material for a movie. :roll:
Furthermore, if someone else "recommended something", that clearly infers it has merit or utility above and beyond other approaches and methods. Correct me here if I have just twisted YOUR words around but it sounds like someone else is recommending simulation. Naturally you can and should take time when new engine concept is being tested from scratch where you may, for example, need to build a three-dimensional mesh of the intake port and exhaust port as well as intake and exhaust tract, run and validate a CFD of the port(s) both forward and reverse, design and validate valve motions, then link all to an engine simulation system. I am sure I am missing a few steps but this is not what we are talking about. These rigorous models are for such things as new concepts or when attempting to tweak performance (emissions, fuel economy, etc...). With analysis, I am a proponent of the KISS principle whenever appropriate and believe it applies to this hypothetical Norton performance question. Complex systems have their place in breaking new ground but a Norton Commando is hardly new ground now is it?
Although a bit off topic, do you think any group can cost-effectively design, cast/machine/fabricate, test on a dyno and repeat the whole process numerous times within two weeks for less money than creating a numerical model and tweaking it? Who is living in the faux world?
Rohan said:
If the dyno of a FA head on a std bike shows north of 45 hp, thats already better.
Regardless of how knackered the old one was.
Enquiring minds, enquiring minds...
Well then, it appears that you are suggesting no need for a baseline dyno pull and that a FullAuto head dyno pull showing anything over 45 hp would be attributed to a FullAuto head.
Rohan said:
Wonder if that chat of say 48 hp has eased some concerns ??
Perhaps someone knows more than they have let on ?
I see a similarity of the above questions and comments with politics and news media today where we are the uninformed/innocent/manipulating posing insinuating questions and/or spread misinformation and repeat it as often as possible until the masses believe it as the new truth. The concept of repeating a rumor/misinformation/lie often enough that people begin to believe it as the truth is as old as the hills.