----- Original Message -----
Sent: Friday, December 07, 2001 10:40
AM
Subject: Re: [Chevelle-List] Spark plugs
& Resistor wire.
You bring up a very good point. I have been
purchasing spark plugs are a 71 Chevelle, when I should be buying plugs for a
1975 something. You have the book, but I thought that HEI where put in 1972
cars. Thanks for the information. I really overlooked the spark plugs
application.
Keith
----- Original Message -----
Sent: Friday, December 07, 2001 10:38
AM
Subject: [Chevelle-List] Spark plugs
& Resistor wire.
Let me try and clear up some
confusion. First, I'm not an expert on this but I do have some knowledge on
the subject.
The HEI was was installed across the
GM car line in 1975 through 1980. After that computer controlled HEI's came
in. The main difference being the external vacume advance housing.
Conventional point dist. can only handle 2.5 amps before burning up. The HEI
can handle 4 amps. More amps, better coil saturation. Since the HEI needs a
full 12 volts to run efficiently (unlike points, 8 volts) you MUST lose the
resistance wire. The HEI can produce 35000 + volts but it needs the full 12
volts to do this. (coil saturation) The resistor wire causes a voltage drop
after starting. During starting it is by-passed. This wire is what kept the
points from burning up. Keith is right about the PINK wire. But don't make
it too long. The longer the path, the less voltage. As for spark plugs and
the HEI, you should be sure to use the right application. Plugs
designed for conventional ignitions should not be used because when you open
the gap you are really bending the electrode at an angle. To fire
efficiently the ground electrode should be flat over the center electrode.
HEI plugs have a shorter center electrode. And this allows for the larger
gap. Larger gap, longer spark. And don't over look the plug wires. You need
at least 8mm wire. Use a good silicone and wipe the inside of the plug and
dist. boot. It not only keeps moisture out but helps keep voltage loss down.
Not to mention easier boot removal. A very good book I bought several years
ago was "IGNITION / ELECTRICITY BOOK by Dr. Christopher Jacobs. It may still
be available. I think it cost around 15 bucks. Hope this small bit of info
helps everyone.
Rich
