Re: Cam tuning

[Shannen Durphey <shannen@grolen.com>]

Well, today I was replacing one of those same optisparks, and I
realized that the optispark is still a distributor, it just happens to
have an optical sensor installed.  If we can make the coil spark, then
we can run the engine, since the rotor and cap work the same way a
rotor and cap always have.  I want to check on this tomorrow, but I
think the opti disk could be replaced with one which had 8 "pie" cuts
to generate a signal for an older ecm.  Another thought is to use the
crank sensor and wheel from a Vortec smallblock.  The vortec sensor is
in the timing cover, and the "wheel" is sandwiched between the
balancer and the timing gear.
Shannen

Scott Knight wrote:
> 
> > OPTISPARK ruins it.
> > No one has come up with a fix for that, that I know of.
> > The optispark has a high resolution, and low resolution part to it that
> > feeds directly to the ecm.  Sy just uses a "regular" distributor.
> > Mybe using an electromotive DIS you could cobble something up.
> 
> I am doing some testing in the next few weeks that should tell me
> whether or not you can just use a crank position signal to drive the
> 8051.  It seems like it should work.  I know the hi-res can be turned
> off.  What I don't know is whether or not it will complain about having
> equal length signals for the low res signal.  There would not be info
> for the PCM to synch up the SFI to the appropriate cylinders without the
> signal pattern the Opti generates.  It might be easy enough to modify
> the pickup signal in a regular distributor to send the appropriate
> signals for the low res.
> --
> Scott Knight  mailto:scott@scottknight.com
> http://www.scottknight.com/ IRC:SS396man
> '95 Black Impala SS
> '94 Ducati 900SS CR
> ----------------------------------------------------------------------------
> To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
> in the body of a message (not the subject) to majordomo@lists.diy-efi.org
----------------------------------------------------------------------------
To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
in the body of a message (not the subject) to majordomo@lists.diy-efi.org