Real tech discussion on design, fabrication, testing, development of custom or adapted parts for Pontiac Fieros. Not questions about the power a CAI will give.
bigblockfiero wrote:Yes I am working on something else but nissan is working on an opposed piston internal combustion engine that solves this 15 degree crank pressure angle issue. The nissan has two pistons in the same bore that are heading strait toward each other for compression up to TDC. Each piston has its own separate crank arm but one reaches TDC a little sooner. One piston starts heading back down wile the other is still coming up so no volume is being displaced but yet the leading piston is achieving a 25 degree crank angle before the power stroke happens. Just imagine how efficient the overlap period can be with all this time to direct the flow volumes.
I've been told by Allen Cline that the 14-15 degree peak pressure angle is independent of RPM or engine configuration. IE, if you have a faster burning chamber and you retard the timing to reduce the pre-TDC combustion losses, timing for peak torque still results in peak pressure around 15 degrees ATDC. That sounds like a characteristic of the gasoline, to me.
There are a lot of mechanically interesting engine designs in the world, but a lot of them are not well thought through from a thermal perspective. Why does a rotary return poor gas mileage compared to a piston engine of equal output? Chamber shape, specifically surface area/volume ratio. If a given design increases chamber surface area relative to the displaced volume above that of the ICE's we know and love, then the new configuration will be LESS efficient because it will dump more waste heat into its coolant (before the useful work of gas expansion is done). It doesn't matter what the specific output of the configuration is, if it gets worse gas mileage than the configuration we use now, it will not survive in the future.
bigblockfiero wrote:It was then discovered in the seventies that we had labled all batteries backward in that flow was actually going from the negitive to the positive.
bigblockfiero wrote:The point is that if the most simplest of dynamics (flow direction) was not known till the 1970's
You said it twice, so it's not a typo.
You're in the wrong century, man.
That's a bad analogy, because the difference between current flow and electron flow is irrelevant. You just have to be aware or consistent with which one you're using to analyze a circuit. That's why the definition of current flow wasn't changed... that difference between model and reality is not important.
bigblockfiero wrote:Yes I am working on something else but nissan is working on an opposed piston internal combustion engine that solves this 15 degree crank pressure angle issue. The nissan has two pistons in the same bore that are heading strait toward each other for compression up to TDC. Each piston has its own separate crank arm but one reaches TDC a little sooner. One piston starts heading back down wile the other is still coming up so no volume is being displaced but yet the leading piston is achieving a 25 degree crank angle before the power stroke happens. Just imagine how efficient the overlap period can be with all this time to direct the flow volumes.
I've been told by Allen Cline that the 14-15 degree peak pressure angle is independent of RPM or engine configuration. IE, if you have a faster burning chamber and you retard the timing to reduce the pre-TDC combustion losses, timing for peak torque still results in peak pressure around 15 degrees ATDC. That sounds like a characteristic of the gasoline, to me.
There are a lot of mechanically interesting engine designs in the world, but a lot of them are not well thought through from a thermal perspective. Why does a rotary return poor gas mileage compared to a piston engine of equal output? Chamber shape, specifically surface area/volume ratio. If a given design increases chamber surface area relative to the displaced volume above that of the ICE's we know and love, then the new configuration will be LESS efficient because it will dump more waste heat into its coolant (before the useful work of gas expansion is done). It doesn't matter what the specific output of the configuration is, if it gets worse gas mileage than the configuration we use now, it will not survive in the future.
Different LS ratios (connecting rod to stroke length) changes the optimal pressure timing by only about one degree but it does change. The point being that the piston will out run the combustion flame at about 15 degrees ATDC but the out run timing will change if the piston speed is altered at 15 degrees ATDC. If the engine design is such as I described then very little displacement changes are occurring at 15 degrees ATDC compared to a conventional engine. If you lit off the mixture in this nissan engine at 15 degrees ATDC the engine would hammer because the overall sweeping displacement isn't changing at the proper rate yet because the other piston is still borrowing displacement back into this chamber. Ill see if this is on the net anywhere and post a link.
bigblockfiero wrote:
Current flow and electron flow is the same thing.
No, they're not. In circuit analysis, "current" is a notional quantity that flows from positive to negative. Electrons flow from negative to positive. As long as you know which one you're talking about, the difference is irrelevant.
Current flow is convenient because it lets you use the right hand rule to figure out magnetic field direction. Electron flow requires the left hand rule.
Where getting a bit off the groove topic but I grabbed this sentence strait from the net (wikipedia) ---------------------------------------------------------------------The moment contact is made, the free electrons of the conductor are forced to drift toward the positive terminal under the influence of this field. The free electrons are therefore the current carrier in a typical solid conductor.-----
So the free electrons are the current carrier going from negative to positive. HMMMMMMMMM so free electrons are flowing toward the positive, free electrons are the current carrier and are flowing toward positive, HMMMMMMMM so then wouldn't current be flowing toward positive also if it was being carried by free electrons? This seems to be saying that current flow and electron flow are going the same way.
One definition for current I saw was, CURRENT----the flow of electrons threw a conductor.
This all jives with the old school teachings and pictures that I have come to know (with the exception that free electrons where then flowing from positive to negative) but then I see as will has said and in a newer internet description that an equal amount of electrons are moving in each direction but the above description said the free electrons were moving toward the positive. So Free electrons flow one way and unfree electrons flow the other? can unfree electrons flow if there not free? are unfree electrons black? In a single solid conductor what do these flows look like? In threw the middle and back from the outside surface? So an inductive amp gauge is measuring flow coming back from the outside? So why don't the polarities of electron flow inductance going in each direction simultaneously cancel each other out so the amp gauge reads zero? Most of my electrical training was over by 1980 and there wasn't much said about this then but I do recall hearing on the evening news that CURRENT was found to be flowing the opposite direction then was previously thought.
Last edited by bigblockfiero on Tue Sep 09, 2008 9:03 pm, edited 3 times in total.
bigblockfiero wrote:will has said and in a newer internet description that an equal amount of electrons are moving in each direction
I did not say (or type) this.
Not equal, no (the net did that), but flow in each direction, yes. That electron flow and current flow are moving in opposite directions. The description I copied stait from wikipedia says that current is being carried by free electrons flowing toward positive so those electrons and current flow are what i'm referring to that are going one way and the unexplained unfree electrons are going the other way.
You don't get current flow without electron flow and my copied sentence states that free electron flow and current flow are going the same way as opposed to the idea that they go different ways.
I knew before this got started that there was conflicting information on this subject and I wonder if newer models disproved what we were taught so they changed some things but not everything and left a bunch of holes in the explanation. This was relevant to the subject that hypothesis are subject to change and everything has not been figured out.
The Dark Side of Will wrote:In circuit analysis, "current" is a notional quantity that flows from positive to negative.
Which way does current flow in this circuit?
What's hard about this?
But like P8ntman said, it really is irrelevant because you get the same result no matter which way it flows. As long as you're consistent with your application of that concept, it doesn't matter.
If you even apply the "current flow is opposite of charge flow" idea to a single moving charged particle as well as the current that generates a magnetic field, you even get the correct answer for which way the field applies for to the particle... but that's a pretty unintuitive concept to apply to a single moving particle.
As for old theories begin shown inadequate... no shit sherlock. Can't pee on your shoe and tell you it's raining. :scratch: :thumbleft:
The Dark Side of Will wrote:
Which way does current flow in this circuit?
Good thing that directional arrow is there or I wouldn't know. So if someone where to see a functioning circuit with that drawing in the wiring diagram, could they erase and draw the arrow going the other way and then would the current know this and so go the other way? :rotflmao:
The only reason we talk about electron holes is back in the day when people were inventing electrons and worshiping the sun, someone rubbed a fur on some amber and called the static positive. Or negative. I forget. And don't care.
So BBF's idea is that quench grooves provide targetted turbulence to the mixture... sort of like direct injection does with lean burn mode. In that case the fuel is injected on the compression rather than intake stroke and ends up mostly captured in a donut shaped space around the spark plug by the shape of the piston and chamber. The overall AFR can be pretty lean, as long as the mixture around the spark plug is rich enough to ignite.
The quench grooves supposedly, at part throttle where a port injected engine has less than ideal mixture distribution, provide beneficial targetting of the mixture at the spark plug.
Here are some chamber grooves that didn't show any real gain but the hp numbers were very good and not reduced at all by these grooves. The intake port flow comes in at the 2:00 position as you see it in this picture so there isn't any place for short turn mixture to hide because the cylinder wall is right there. Not like a wedge head with a big quench area at the short turn side.
If the mixture flow had come in at the 12:00 or 11:00 position then there would have been grooving gains (or part throttle losses) as I have seen on a reconfigured head. This does make the chamber design less desirable (at part throttle).
On this particular head I have since cut the exhaust valve seat lower, then milled the head more and dynoed, then cut the exhaust seat lower again, then milled the head and dynoed again, then cut the exhaust seat lower again, then milled the head and dynoed again, and so on so the intake seat would be higher then the exhaust to experiment with flow exchanges that occur during the overlap period. The grooves are not on this head anymore and it has since made more midrange torque and just a little more peak hp at the same compression ratio.
Last edited by bigblockfiero on Fri Sep 12, 2008 6:53 pm, edited 11 times in total.
bigblockfiero wrote:Here are some chamber grooves that didn't show any real gain but the hp numbers were very good.
I totally changed a set of spark plugs in my friend's turbo LS1 the other day. They didn't make any difference, but it still made good numbers, so they are the best spark plugs made. Period. End of discussion.
Nice reasoning....
88GT 3.4 DOHC Turbo
Gooch wrote:Way to go douche. You are like a one-man, fiero-destroying machine.
bigblockfiero wrote:Here are some chamber grooves that didn't show any real gain but the hp numbers were very good.
I totally changed a set of spark plugs in my friend's turbo LS1 the other day. They didn't make any difference, but it still made good numbers, so they are the best spark plugs made. Period. End of discussion.
Nice reasoning....
If you read more of the thread you will understand (by my tinkering) that the grooves help on a wedge head or v-type engine which this head doesn't simulate. Also I now edited that last post several times for more included content.
Yah, those groves are mostly good. I heard BMW started using that design in their most recent M3 motor. The all aluminum, 32 valve, 8400rpm, 100+ hp/l, smooth as silk, ITB intake, tuned equal length headers, an O2 sensor on each header, Alpha-N fuel injection, and God only knows what else.
Except they aren't.
Weird that they would spend billions of dollars raising the bar of production internal combustion engines, and ignore a technology that's dirt cheap to employ, increases power output, increases gas mileage, and lowers emissions, all without any negative side effects. I guess specific output doesn't matter to them.
:scratch:
88GT 3.4 DOHC Turbo
Gooch wrote:Way to go douche. You are like a one-man, fiero-destroying machine.
Aaron wrote:
Weird that they would spend billions of dollars raising the bar of production internal combustion engines, and ignore a technology that's dirt cheap to employ, increases power output, increases gas mileage, and lowers emissions, all without any negative side effects. I guess specific output doesn't matter to them.
:scratch:
I don't know the story, but there could be a patent on them.
It's like the battle of the razors... _insert story about Mach3, Schick Quattro, Gillette Fusion_
Then I asked myself, has that ever stopped the automobile manufacturers before, on new and innovative technology? I don't really think so. I'm quite sure the company who made the first production car with fuel injection didn't invent fuel injection.
The automobile manufacturers have resources beyond what any of us could even grasp. If they wanted to cut some grooves in their cylinder heads, I'm sure as shit they'd find a way to do it. And if it meant spending millions to bigblockfiero, they'd do it, in a heartbeat (If these grooves did even 1/4 of what he claims).
So, bigblock, you a millionaire?
88GT 3.4 DOHC Turbo
Gooch wrote:Way to go douche. You are like a one-man, fiero-destroying machine.
