Re: Re: rotor for 20v turbo engine

[C1J1Miller@aol.com]

In a message dated 11/5/98 8:58:50 PM, wallace@remdesign.com wrote:

>Could this be? It seems like the tip of the rotor can't be too wide
>unless it is greater than (360 deg / NumCylinders - a little), i.e. as
>long as it's only connecting to one plug at a time.
>
>Not to say that you shouldn't be able to get the right part, of course.
>
>- Wallace
>  '87 5kcstq 150k

If you think about the distance between the 5 points on the cap, and the width
of the rotor tip, the wider rotor tip will allow the spark to travel to the
next cylinder before the narrower tip would.  In other words, the timing would
be advanced to that cylinder.  Now, put in high rpm, modified computer, high
temps... 

The ECU could be advancing the spark pretty far for more power, especially in
the modified computer; then consider the wider rotor tip advances the spark
even more than the ECU expects (actually to a point where the piston is still
moving up to compress the gas/air mix).  If the spark happens _enough_ before
top dead center, you could get ignition and combustion forcing the piston
_down_ when it should be moving _up_.  This is preignition, and can blow or
seriously damage an engine.

That's my theory, anyways.
HTH chris miller, windham nh, c1j1miller@aol.com
http://members.aol.com/c1j1miller/index.html