Engine Smoke
Dear Dr. Motorhead,
I was watching ESPN last Sunday and was very pleased and excited to
hear of Piston's great accomplishments and success as Captain of the
University of Hawaii’s hockey team. I couldn’t believe how many
goals and assists that he has accumulated in such a short time. You
must be very proud and perhaps a little nervous that he won’t
follow his academia and become a professional hockey player. I know
how busy you are and your desire for him to transition into your
studies and continue with your writings. Continue the family
tradition as it were. Notwithstanding, his future contributions to
the greater internal combustion and gear head societies.
However, I need to discuss with you
my problem. In fact, I think I may have a greater problem than I can
possibly deal with. Especially, with my current Executive position
as of the American Lung Association. Doctor… my engine is
smoking!! I can’t allow this story to leak to the public without
first a positive outcome or a proactive position. My job and
certainly my credibility are on the line. Please, I need your input
more than you can imagine. I need to make a statement before this
story gets leaked to the press. Even worse, CJ, the gossip reporter
from the Star/Tribune may latch on to this like a pack of mad dogs.
The smoke emitting from my exhaust is
white. The situation seems chronic. Doesn’t matter if the engine
was just started or has run for a while. In fact it gets worse the
harder you work the engine. The smoke was at it’s worst late this
fall, while taking the boat out of the water on a very chilly
Saturday morning for winter storage.
This story is true, however I have
changed my name to protect my anonymity.
Signed,
Smoke Stack Lightning
Dear Lightning,
Seems to me I remember a song by that name. I hope you’re not in
trouble for any copyright infringement. I’ll forward your letter
to Piston. I know he will love to hear your thoughts. U of H is
doing very well. They lead the whole South Pacific Collegiate Hockey
League. The competition is fierce. All the kids are aware most of
the major league scouts are keeping a close eye on the many
prospects in this very competitive division. Follow his academia? I
thought that was a kind of nut like a filbert, I’m not sure why he
would follow these. However, I do know he will choose the best path
for him. If he decides on a career in the NHL, perhaps I could
solicit Steve Merjanian, Jack Dukes or even Tonka Bob to follow in
his footsteps. One step at a time, I’ll take on the challenge as
it presents itself.
Now, let’s deal with the smoke
issue. There are three types of smoke that emit from an engine,
white, black and blue. Actually there is a fourth, however this
comes from Todd Warner’s cigar. It’s not uncommon to see smoke
emitting from the strangest locations as Todd sneaks around, trying
to scoop yet another deal.
We might as well start with the
worst -- blue smoke, or bad juju as they say in the South Pacific.
What does this mean? Your engine is telling you something, just as
our sparkplugs do. Blue smoke is the result of oil getting into the
combustion chamber. The burning of this oil and gas is the blue
emission. Although the smoke may vary from a light to a darker shade
of blue, the make-up is the same. The darker the blue, the worse
your engine’s condition. This blue smoke may also be visible at
the crankcase breather. This is the pipe that protrudes from the
engine block to the carburetor on our older flathead motors. The oil
gets into the combustion chamber through worn piston rings, cracks
in pistons, or worn valve guides. Either way, it is time to get your
engine into the shop for a rebuild.
Remember as a kid, the old outboard
motor you had? It would leave behind little bubbles filled with a
bluish oily mixture on the water. That’s because you mixed oil
with your gas in a very rich 20 to 1 gas to oil mixture. The
underwater exhaust made all these little smoke filled traces. Not
only was it very polluting, it made it easy to follow your trail
back home when on a strange lake -- kind of like dropping bread
crumbs in the woods.
Black smoke is a much less menacing
problem, caused by an overly rich, or too much gas-to-air ratio
burning in your engine. The air and gas mixture needs to be balanced
properly. Too much gas and you get this black diesel-like emission.
Don’t worry, this is easy to fix; simply an adjustment to the
carburetor or perhaps a carburetor rebuild. If you have a newer V8
engine with an automatic choke, your problem may also be here.
Sometimes these chokes get stuck and don’t allow enough air to get
into the engine. This is easy to check on new engines as well as the
older ones in case you are forgetful and forgot to push the choke
cable back in on the manual models. Remove the flame arrestor from
the top of your carburetor. Look into the choke; there is a large
plate just inside the throat or opening. This plate should be in the
open position, not closed off. If it is closed, it can usually be
manually opened without too much trouble. Push it open and you
should be good to go. If it is an automatic choke, don’t forget to
fix the problem.
I’m sure your cohorts at the
American Lung Association would prefer you to be paddling a canoe or
rowing a skiff, however your problem is the sign of a healthy
engine. White smoke is formed by water vapor. Many refer to this
vapor as steam, but it is not. If your boat is equipped with a
thermostat, chances are you will have more white smoke or water
vapor emitting from your exhaust pipe than those without. When you
operate your boat in the early spring or late fall, this vapor
becomes more visible as the air temperature is lower and cannot hold
as much moisture. Then the vapor becomes more visible. It is the
same as early morning fog above the low-lying valleys or swamps. As
soon as the day warms up, the air has the ability to hold more
moisture and this visible moisture or fog disappears, and is
absorbed by the warmer air. Another way to look at this is, your
breath is more visible in January than in July. No way is this
steam. If it were, your body temperature would need to be 212
degrees fahrenhiet. So, when the white smoke was worse on the cool
fall morning, that is because it was just more visible. When you are
working your engine hard, you’re just producing more water vapor.
In addition, the more moist the air, the more moisture-laden air you
are pulling into your engine and the more moisture you are
expelling. For those of you who studied chemistry and physics, P V =
N R T is a good formula to remember when you have this discussion
with a brain.
Need to know how an engine is
performing at a glance? Take a look at the exhaust pipe. If the
engine is running perfectly, the inside should be a shinny copper.
Too rich, it will be black and sooty. Burning oil or experiencing
blow-by, there will be an oily coating or residue.
There you have it, Smokey, it’s just that easy. See you all at the
Minneapolis Boat Show. You will recognize me as the one wearing the
University of Hawaii hockey jersey. Gee I’m proud of that kid.
Signed
Dr. Motorhead. |
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