I know there's an MV connection in here somewhere so are you saying that
you run your MB in enduros and your Command Car in the demolition derby or
do I have it backwards? As to the other stuff...
> I've been told by regional engine gurus that the race engine will produce
> more power and less emissions even on leaded gas because it is so much
more
> efficient. True?
Not true. I assume you're trying to say that they are telling you they
have increased the thermal efficiency of these motors and that they are now
capable of extracting and using more of the BTUs contained in each gallon
of fuel and will, therefore, produce more power from any gallon of fuel,
racing gas or not. This is not the case. What they *have* done is
increase the engine's ability to process more fuel/air mixture per unit of
time. Any engine is just an air pump. Essentially, what they have done is
increased the engine's ability to pump air but not by increasing its
efficiency. They've done it by spinning the engine faster, by using bigger
openings and keeping them open longer to intake and then eliminate air and
fuel, by creating longer torque arms, bigger cylinders and more leverage.
The engine is not more efficient, just a voracious consumer. In fact, with
emissions of no concern I'm certain that all these engines run,at least,
rich, if not over-rich to avoid dreaded flat spots in throttle response.
(Of course, seriously over-richness leads to its own throttle response
problems.)
The only conceivable increases in efficiency would come from reducing
friction (the largest single efficiency robbing factor in an IC engine)
like clearancing and running fewer or looser piston rings and increasing
compression. But the octane and ignition lead required to take advantage
of the relatively high compression would render the engine an absolute dog
on pump gas. The heat of compression generated by the piston long before
it ever reached TDC would ignite the low octane non-suppressed volatility
fuel about half way up it's stroke and try to drive it back down while it
still wants to travel up. This explosion trying to "slap" the piston back
down, prematurely, is what you hear as "pinging", "spark knock" or
"preignition". If you ever watch the probe of an emissions sensor as you
advance the timing until it pings you'll see the emissions skyrocket,
while power falls the table. The decreased friction would, however, be a
legitimate long term gain which would apply cross the board.
> I don't know but they do spend their lives perfecting the small block
Chevy so they must know > > something.
Perfecting? I doubt it, not at that level of racing. Modifying? Sure.
Remember, these are the same guys you see with aluminum everything on their
race car, rifle drilled axles, Swiss cheesed engine mounting plates, etc.
and then they weigh 400 lbs. and have some one hand them a sausage sandwich
once they're sitting in the car. They could save more weight on the car by
skipping lunch than buying expensive lightweight parts.
At our local DIRT track, the resident "gurus" were shocked when after
screaming bloody murder that the, about to be required, mufflers would
upset the delicate balance of their finely tuned "mountain motors" found
that the mufflers and resulting backpressure, actually, increased their
power output. The "some is good, more is better, so too much must be just
enough" engineering crowd had neglected to even consider tuning or matching
their exhaust system's backpressure to their induction system. They just
figured, the least amount of restriction to getting the exhaust out had to
be the best solution. Puts me in mind of the guys in the gym with the 24"
biceps and the milk bottle legs.
> STORY WARNING......A few years ago a track in southern New Hampshire had
to
> survive the attack of neighbors who had moved in despite the pre-existing
> track. They tried to complain about noise and claiming to be
> environmentalists added that the increased emissions were hurting them,
the
> trees and the woodland creatures and the track should be closed. So they
> hired investigators to take lots of measurements and the results stopped
the
> complaints cold. Turned out the noise from a track surrounded by pine
trees
> was less than the noise from their own development!
You think folks grilling chicken is noisier than a race car? Even if it
is, the point is that the track noise is *in addition to* the noise folks
generally consider a necessary evil.
> Then the emissions were tested and they found the track full of cars
produced less emissions than > the cars passing by on the road!
What were the parameters here? What cars? Passing when? For how long?
Why just compare the neighborhood cars to the race cars? What about all
the emissions of the spectators cars and trucks, race car haulers, etc?
How about the grease fumes from the fried dough? And spectators'
flatulence?
I doubt that is true but it reminds me of folks complaining about the Indy
500 during the first Gas Crisis when, in fact, Indy cars run on methanol.
The gas used by spectators' cars might have been an issue but that paled in
comparison to the gas used by spectators attending multiple NFL football
games, every weekend, all season long and no one was suggesting that the
NFL season be cancelled.
> In the end the track was asked to beautify the place a little so they
planted geraniums along > the backstretch.
Sounds like the "guy died in his Cobra", '53 Chevy in barn turns out to be
Corvette", "$44 Jeeps in crates" stories to me.
Regards,
JP
===
To unsubscribe from the mil-veh mailing list, send the single word
UNSUBSCRIBE in the body of a message to <mil-veh-request@skylee.com>.