Bob Tom <tigers@bserv.com> wrote in message
news:5.0.2.1.0.20010630113805.009fab50@bserv.com...
> Just a couple thoughts.
>
> We all see the advertised "Power Output Levels" that many ignition
> manufacturers use to build interest in their products. Yes, it's true
> ... many ignition manufacturers will tell you whatever it takes for them
> to get you to believe that their ignition is the best :-)
I thought MSD was one of the few manufacturers that tried to dispel the
myths of "mega-voltage outputs"? Have they changed their marketing line?
> One of the good ones is advertised coil output and also aftermarket
> Ignition Unit output (usually an Inductive Electronic or CD "Capacitive
> Discharge" Unit). What people tell you is that you MUST have the
> highest output ignition unit because it's the best.
>
> What really happens is that your engine (each cylinder) will ONLY use
> the amount of voltage it takes to jump the spark plug gap and fire the
> air/fuel mixture in that cylinder. Your engine requires a lot less spark
> than what is advertised. Even if you have a Gazillion Millijoules of
How much is a Gazillion? If 1 Gazillion = 1000 millions, and a Millijoule
is one millionth of a joule, then a Gazillion Millijoules would be roughly
1000 joules, right? ;-)
> advertised output, if your engine only needs 20,000 volts to jump
> the plug gap, that's all the unit will give. What they should tell you
> is that the unit "can" deliver up to that rating if the engine demands
> it. So, does your engine really demand that much voltage output
> ... probably not.
>
> Want another misnomer? Well, this one is on multi-strike ignition
systems.
> You probably may not have guessed it, but the analog multi-strike has
> less time as engine RPM increases to get off as many sparks. Do these
> extra sparks help your engine? Not really, the major concern is the
actual
> spark duration in "Crank Degrees" that you have for each spark on each
cycle.
> Most aftermarket ignition manufacturers give you 20° of spark duration
with
> each
> spark. Now, this spark will not carry full voltage over the entire
> 20°. As the spark
MSD was always good about pointing this out, also. I haven't read their
advertising in quite a while..... have they changed it?
> duration continues it loses voltage output. The reason behind the longer
> spark is
> to make sure there is a complete and thorough burn of the air fuel
> mixture. With
> high dome pistons, tight valve shrouding and other issues, you can get
portions
> of your mixture that do not get a decent ignition. By holding the spark
up to
> 20° of crankshaft duration you virtually eliminate these problems (if your
> engine is in proper tune). Having a greater voltage hold over the entire
20°
> should be more of a concern than peak voltage output.
>
> BT (RT to some)
FWIW, I don't race, I just like high performance on the street, so the MSD
suits me (and my GenII Dak).
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:01:56 EDT