Re: [Chevelle-List] Spark plugs & Resistor wire.

[Keith Cooper]

The spark plugs recommended for a 1971 Chevelle is AC R45T with a gap of .035. The plug for a 1975 is R44T with a gap of .060. The plug for a 1976 is R45T with a gap of .045. The plug for a 1977 is R45T with a gap of .045. My question is- being that I am using a HEI dist. what should I set the gap at, .060 or .045  The second question is should I go to a R44T plug. My third question is should I look at a better coil. I now have a stock HEI coil. Can you buy a High Perf. coil which will fit inside the top to the stock HEI dist. cap?? Keith ----- Original Message ----- From: Keith Cooper To: [EMAIL PROTECTED] 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 ----- From: Richard Milkiewicz To: CHEVELLE 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