----- Original Message -----
Sent: Wednesday, June 29, 2005 1:43
PM
Subject: [Chevelle-list] Rookie question
"Mallory HEI"
Yes! Where as the old factory coils had an output of about
20,000 volts, HEI coils have an output of about 40,000 volts. The reason they
put the coil inside the distributor cap was to reduce the distance
the current had to travel (more energy to the plugs) AND to reduce the
likeliness of it arcing.
In fact, I believe the reason that the top of the distributor is so
much larger than before is to not only house the coil, but to spread out the
plug wires, again to reduce the likliness of an stray arc. When they first
came out with HEI, it was such an increase in voltage, that I guess plug wire
insulation needed to improve to handle it better. Now you will see some 40,000
volt remote coils being used with smaller distributors. But you better use
quality wires if you do this OR when you use a remote coil.
Of course, the less amount of ohms per foot of wire is a good idea
anyway. The reason they started using coiled wire inside a plug wire is
to reduce radio interference, but it also increases the distance the
electricity has to travel, and therefore increased resistance. So
comparing wires and going with the best you can afford is a good
idea. You may be making a trade off on performance for better radio
suppression. Of course the type of wire used, and it's diameter play key roles
in the amount of resistance per foot. You will pay more for better wire
most of the time, but you get what you pay for. Copper is one of the best
conductors, but silver is better. I believe I seen some silver plated copper
one time? I doubt you will see gold wires or platinum, but that's the
only material that's better than copper and silver. Any other type
material used for the conductor is going to have more resistance per foot.
Don't go cheap on plug wires...ever.
Also, make sure you know the correct plug gap for your HEI. The increased
energy allows a wider plug gap and still the electricity will jump the
gap. If anything is off here ( too much resistance in wires, plug gap too
wide, bad connections on the coil, etc.) with an increased plug gap, you'll
have major problems. If the plug gap is not wide enough, you won't
get the full benefit of the HEI.
One last thing. They started using resistor plugs to reduce the current
.....which reduced radio noise. Bad idea! A major trade off in electrical
system performace for a more quiet radio. There are better ways to reduce
radio noise. So when you go get spark plugs, if they have an R in the number,
like R44 ..it's a resistor plug. By using a resistor plug, you'll be
sacrificing somet of the increases you just made with an HEI
system. Try to get an plug without an R in the number. If you get radio
noise, consult your local electronics store for options.
Steve
Does the built in coil replace the std
coil?
Pelle Andersson
