Right
place—right time(ing)
The response from the article
“Attitudes about Altitude,” posted on the Rocky Mountain Region’s Web site and
sent out with each Grand National registration confirmation, has had the phone
rather busy at the old “Workbench” with calls from all over the country.
There have been numerous questions about bringing cars to
Some
questions are quite realistic, and others—well. You can’t help but wonder how
some Easterners visualize our Western culture and high altitude.
For
example, when a gentleman called me with questions about his car’s performance,
he also wanted to know if the parking area for the show cars would be separated
from the horses. It was hard to figure out if he thought our civilization had
not gotten past the horse-and-buggy era, or if he believed from the article
that most of us rode horses because of the altitude. Hopefully, I calmed his fears.
Most
of the questions were about car performance at our altitude and more specifics
about possible adjustments needed. One of them even stated that he thought the
reason our Denver Broncos (and Avalanche) did so well was due to the fact that
our teams trained in this high altitude and therefore had an unfair advantage
over teams that trained and played at sea level.
I
tried to keep a straight face for most of the inquiries, but one of them really
broke me up and I want to apologize for not taking him serious at the time. He
asked if he should get an oxygen tank to put in his trunk and run a hose up to
the air intake in order to drive his car while here. I thought he was kidding
until he asked how our local people hooked the oxygen line up to the air cleaner
to help our cars run at this altitude. It took quite a bit of explaining to
convince him this was not needed. It will be interesting to see if he actually
shows up with his car equipped this way.
The
majority of the questions were about timing and how critical it would be to
adjust the timing for the trip. Many of them very thankfully accepted my advice
and put their fears aside. Quite a few expressed a belief that in fact, the
fuel mixture and carb settings could affect performance at altitude, but, timing
was a mechanical thing. Because of this, timing would not be affected by
altitude. In reality, the timing actually has more influence on performance at
high altitude than fuel mixture. The reason for this is very basic.
Our
motors are referred to as “internal combustion engines,” because a combustible
mixture of fuel and air are introduced into the internal cylinders. At the
precise instant the piston reaches the right position near the top of the
compression stroke, the spark plug fires and causes an explosion in the
cylinder, forcing it down on the power stroke.
At
1,000 RPM (fast idle) in a V-8 engine, there are over eight explosions every
second. You can do the math for higher RPMs at road speeds. Heavier air (such
as at low altitude) results in the faster and more powerful the burn in the
explosion. As the air becomes lighter, such as in high
altitude, then the slower the burn. In other words, if the air is
thinner, the time the spark fires until the explosion reaches peak power is
longer.
To
compensate for this, the spark needs to fire microseconds sooner so the piston
can gain the maximum power from these explosions. The amount of time difference
when the spark fires and the piston reaches top dead
center is measured in “degrees.” The distributor will automatically adjust
itself by centrifugal weights and vacuum from the carburetor to compensate for
engine speed and load. In other words, the faster the engine turns and the
faster the pistons travel, the more advanced (earlier) the spark must be.
Up
to the early ’30s, most cars had had a control lever or knob to retard the
spark for easier starting and to advance it for driving.
I
hope you understand a little better now why the right timing, for the right
places, applies in regard to your old engine. Of course, modern iron uses
computers to take care of all this.
In
regard to you yourself, the right place to be is at the Grand National here in
See ya there,
—Walt