[Spridgets] Electronic Ignition

Dean Hedin dlh2001 at comcast.net
Thu Mar 19 17:50:14 MST 2009


GM had introduced electronic ignition in the early 60's, way before the serious emission laws.
There were aftermarket items early on as well, like the Judson unit.
The early systems were still with the points but the points now carried low current as Peter C described,
so they did'nt arc and become pitted.

It would take some deeper research to determine when the points actually disappeared and were
replaced by magnetic or optical sensors, but this was probably in the early 70's, and it was probably 
done by Bosch.

There is an emmision component, dirty points misfire, thereby increasing hydrocarbon emmisions.
On the flip side it means you also get better mpg when you get rid of the miss-firing points, which 
was the big selling point early on.

----- Original Message ----- 
From: Chris King 
Subject: Re: [Spridgets] Electronic Ignition


I have to believe there is am emissions control component to the adoption of electronic ignition. 
GM HEI showed up in cars as cheap as the Vega and the Chevette in 1975 or so. The BL 
cars sold in the US got electronic ignition (remember those OPUS units, you 1500 guys) in 1975 
as well, while the UK kept points up to the end of production. Why would BL (or GM, for that matter) 
put a more expensive component into the car unless they absolutely HAD to? 


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