Non-SE-R: GM OHV engines

Jack Ray rjrjack@knology.net
Wed, 4 Dec 2002 21:45:38 -0600


> Rick Frey wrote:

> >I have always been told that one of the major advantages of 4 valve heads
> >lies with the pentroof (5 sided) combustion chamber configuration.
Having
> >more, smaller valves allows much more flexibility in designing the
> >combustion chamber shape.  Proper design allows running higher
compression
> >w/o detonation, all other factors held constant.  I guess this would be
> >true regardless if a cam or rocker arm opens the valves, but how many
DOHC
> >engines have less than 4 valves/cylinder these days and how many rocker
> >armed motors run 4 valves/cylinder?

George wrote:
> Well, the SR20DE for one. :-)

> Yes, among the advantages of 4 valve heads are combustion chamber
> configuration.  You are correct about the effect it can have on being
> detonation-resistant, but there are others.

> 1) Lighter valve train (as already mentioned) allows for higher revs.
> 2) Smaller valves are not only lighter, but allow for greater total valve
area.
> 3) Fewer parts, greater reliability.

> Jack Ray wrote:

> >Ain't nothing wrong with GM's V8's.
George wrote:

> Nope.  They're great for pulling trailers and plantin' 'taters. :-)

> Jack Ray wrote:
> >Ain't nothing wrong with OHV engines.

George wrote:
 > For pulling trailers and plantin' 'taters.

They're great for other tasks too, but feel free to be biased. :^)

> >I'm kinda turned off about Corvettes nowadays, because GM, to beat the
> >Vipers at LeMans

> And how do you think DC builds the LeMans Vipers?

Well, I thought, "I've got him on this one."  And damn if I could find
anything on
the web to back me up, in fact the opposite, so I stand / sit corrected.

Jack wrote:
> >When all the gas is gone, it's gone.

George wrote:
> Yep.  Back in the early 70s they said it would have been long gone by now.
Uh -- help me out here, I'm trying to find the relevance.

> >People have no idea how much we depend on oil for our way of life.  It's
> >the source of plastics, gasoline, lubricants, heat for our homes, and a
> >major fuel for electricity generation.

> But, there are alternatives for all those things.  When petroleum actually
> does get really scarce, those other alternatives will gain favor.

Well, if after a good bowel movement you realize that there's no toilet
paper,
then your finger is an alternative for that toilet paper, but I'll bet that
you
would prefer toilet paper.  And that's the case with petroleum.  There are
no
good alternatives, not any that can be produced in sufficient quantities.
Here's some data from the MIT web site:
"The total amount of gasoline sold in 1990 in California was 5.0E+10 Liters,
and of this total, 97.3% is used by on-road vehicles."
That's, what ? over 1 TRILLION gallons of gasoline burned in just one year
in just
California.  There's not enough available land to grow the biomass required
to
replace that gasoline with ethanol/methanol - not even close.  And don't
mention
natural gas - people will be wanting that to heat their homes.
The world will go on, but not with the same ease it now enjoys.

> >It's hard for me to be excited about companies that do such a vigorous
job
> >of promoting the sale of 12 mpg pigmobiles, and truly don't give a rat's
> >ass about the harm their products are doing the world.  They just make a
> >few pretend efforts to improve gas mileage, to appear socially conscious.
> >Life's gonna be much harder all over the world when the oil's gone, and
> >America is the biggest pig at the trough.  By far.

George wrote:
> Please elaborate on the harm automobiles are doing to the world.

I did NOT say that automobiles are doing harm to the world.  I specifically
said
12 mpg pigmobiles.  That translates to Suburban, Expedition, Excursion,
Excretion, etc.
A 12 mpg Suburban emits at least twice the carbon dioxide that a 25 mpg car
does,
and even a higher ratio of the other types of chemical pollutants, since it
does not have to
clean it's exhaust up as much as an automobile.

George said:
> Cows emit more hydrocarbons than automobiles today.
Are you too polite to use the word 'fart' ?? (smile)...

As for being socially conscious, the buying public couldn't give a rat's ass
about it.
So you're agreeing with me here...

>The auto makers answer to a greater power than tree huggers.
>They answer to the marketplace.  It's goofy to expect them to
>do otherwise.
Tree huggers?  That's a Rush Limbaugh (sp?) tactic, apply a derisve label to
anyone who has ideas you don't understand or care for.
And I hope you know that if it weren't for trees, you'd be dead now (biology
101).  Go hug a tree, George. You might like it. :^)
And I never said anything about expecting people to do otherwise than they
do.
I just bitched about their SUV's (lack of) gas mileage.

> When the oil's gone, cars will likely be powered by methanol.  I guess we
> can complain about the price of corn on the cob when that happens. :-P
We (or our descendents - whenever it happens) will have a LOT to complain
about.

> >It's hard to get mad at the true source of the problem, which is the
> >people who buy those pigmobiles.
>So we should be mad at the auto makers?  Be real.
I don't think I'm really mad at them.  I know I didn't SAY I was mad at
them.
What I don't like is the consequences of their profitability-driven
behaviour.
What I also don't like is the consequences of the behaviour of those people
who, as you say, don't give a rat's ass about social consequences.

> >A lot of them are really nice people.

> Gee, you think?
I guess, upon reflection, that I deserve that.

> >It's just, I guess this is it, that gas has always been available at the
> >gas station, just there like the sun and rain, and people just don't
think
> >about it running out.

> Perhaps that's because the tree huggers have been saying for over 30 years
> we would run out of the stuff in no time.
But more likely it's because gas has always been available at the gas
station,
just there like the sun and rain, and people just don't think about it
running out.

>  There are more known oil reserves in the world today than 30 years ago.
There's no more oil than before, just more advanced means of finding it (and
more need to find it - wonder why?).

> What's more is technology is making it more and more available.  But,
you're
> right.  When it's gone, it's gone.  Then we'll drive cars powered by
methanol
> or something similar.
Yea, we'll find a way of taking hydrogen out of water (without lessing our
water
supply), or we'll develop a solar cell that produces 400 hp with 1 square
foot of
area, on a cloudy day), or we'll find a way to convert coal into fuel
without actually
having to do the mining it would require (and we all know we'll NEVER run
out of
coal, right ?), or we'll plant biomass farms on the moon, or we'll --
George, there
are no good substitutes for oil's many uses, it's essential to our way of
life, and to
just senselessly waste it is DUMB!!

Got any new products at your company ? :^)

Jack (doesn't hug trees but enjoys their company) Ray
94 SE-R