63 Small Block Distributor / Firewall Clearance

chryslerfat,

Below is my understanding. Add a "I think" caveat to every statement.

Many cars with a coil-pack do have a cam sensor. I know my 2.4L does since I changed it, and recall my 3.8L does. However, the cam sensor is not used in spark control. It is only used to time the fuel injectors to the valve openings, which slightly improves emissions at low rpm. That is termed "sequential multi-port fuel injection", as opposed to "batch-fire mode". Each spark plug still fires once per revolution. The extra spark is on the exhaust stroke, and is hardly needed, thus the term "wasted spark". It actually does slightly improve emissions by helping burn left-over fuel, I have read. If not true, then somebody explain why my 2.4L coil-pack connector doesn't have enough pins to control 4 spark plugs individually. I recall it is 3 pins (+12V, coil1, coil2). If you look at it, it is obvious that two plugs share each coil. Not to say there aren't coil-packs somewhere with one coil per plug. If so, one might term "Coil Off Plug". You can find just about any flavor of engine control somewhere. The mega-squirt site has much info.