[Diy_efi] The Hunt effect

[Adam Wade]

--- John Gross <jogross3 at hotmail.com> wrote:

> Oops...sorry about the *typo*...I guess I should
> take better care when crafting my emails, even when
> exhausted after a long day of trackside
> engineering.

Hey.  You're the one that started arguing with ME
about it.  And you were the one trying to make
semantic points from the get-go.  Don't hold me
responsible for when you reply to posts, or how you
arrange your schedule.  If this wasn't something you
were prepared to defend, why did you bring it up?

> Now you're playing a semantics game...

Not really.  I've never heard of an drivetrain
engineer who would refer to the combustion chamber
roof shape (a term you introduced to this
conversation, and which you  appear to have edited out
in your reply) as "the combustion chamber".  It's not
only literally inaccurate, it's technically inaccurate
as well.  And I doubt very much there would be a
widely-used term for it ("roof") that was not used to
refer to anything else if there was no need to make a
distinction between roof shape and chamber shape.  Of
course, the distinction is essential.

>> What's more, it has very little in and of itself to
>> do with turbulence, squish, combustion, and even
>> spark advance.

> It does?  So the shape and configuration of the head
> has little to do with spark advance, turbulence,
> squish and combustion? 

If you could let go of your sarcasm long enough to
actually read what I wrote, you would see the words
"in and of itself" in the quote above.  The racing 911
combustion chamber is an excellent example.  Would you
say that a flat-top piston in a hemispherical roof
combustion chamber would give similar results to one
crowned so high as to achieve a 13:1 or better CR? 
Somehow, I think you can see the absurdity of that. 
However, the chamber roof has changed not one iota. 
It's the piston crown that has changed, and that has
made a radical change in combustion dynamics.

*snip remainder of sarcastic comments that are based
on a misunderstanding of what I said*

> Yes, you must know what is going on with the piston
> shape, installed height, head gasket thickness, and
> many other things to know the WHOLE picture.

There you have just contradicted yourself again. 
*sigh*

And I'm not talking about the "whole" picture; if you
want to, we need to talk about spark energy and
timing, fueling, intake and exhaust porting and
tuning, cam timing, valve head size, and on and on. 
What I said, and what I know to be true, is that it is
useless to make any sort of statements about the
characteristics of a particular chamber roof design BY
ITSELF.

> engines with hemispherically-shaped *I don't know
> what Adam calls them* in the head are technically
> "hemi" engines.  

Ooh, more sarcasm.  This time it just looks stupid,
though, because I've told you a dozen times in the
past several days what they are actually called. 
ROOFS.

And they are not technically hemi engines.  They are
colloquially hemi engines.  Find me any SAE technical
reference that refers to a hemi-roofed cylinder head
being referred to as a "hemispherical combustion
chamber".  Any one will do.

>>> it is ALWAYS called the "combustion chamber"

>> By whom?

> See my comments above.

You never answered the question, above or anywhere
else, as far as I can tell.

> Again, trying to discuss differences in the "part of
> the combustion chamber made up by the head", which
> all of the Detroit, IRL, and NASCAR engineers I have
> worked with over the years refer to as the
> chamber, but apparently, they don't know what
> they're talking about either, right?

Perhaps you could ask them all what the difference is
between the chamber roof and the chamber shape.  I'll
bet you $1000 cash not a one of them would say "oh,
they're the same thing".

> No, I haven't read the archives, because some of us
> have more important things to do with our time than
> sift through endless archives of emails mostly
> containing information already known to them,

Then how do you have time to read all of the current
ones?  You seme to have enough time for sarcasm.  What
about the time of the people who already answered all
the questions several times over, allowing most
questions to be answered by a search of the archives? 
Your time is more important than theirs?

> and what content is in there that isn't already
known 
> to them, will be more efficiently obtaining working
> on the dyno at work, looking at IMEP traces,
studying
> combustion events, etc, etc.

So I say again, Mr. Erudite; Why are you here at all,
much less posting?

> I'm sorry that you had to prove to me that the
> warnings I privately received from some folks about
> certain members of this list being pompous,
> self-righteous asses is true.

*laughs*  You come here to discuss a highly technical
field (at least, that is what the group is FOR, more
or less), and when someone makes some highly technical
points, and you don't agree with them despite there
being validity to the original points, they are
"pompous self-righteous asses"?  Sounds like a
self-worth issue to me.  You certainly were beating
your "expert" breast up above with dropping all of the
race engineers who disagree with me.  Wouldn't that
make you easily as much of a "pompous self-righteous
ass" as anyone else here?

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