Multi Spark on or off?

[tortuga]

The daytona sensors control box programming software has a switch for multi spark. The manual seems to encourage turning it off as it may cause cross spark to the next terminal? At least thats how i read it...

Thoughts?

[Gaz64]

Steve,

For any conversion to electronic timing using a distributor, especially if using multi-spark, the rotor phasing MUST be addressed, either with an adjustable rotor, a phaseable reluctor wheel or an adjustable trigger sensor plate. I use a spare distributor cap, drilled with large holes to verify phasing with a timing light.

With potentially 30 degrees of advance, (mechanical and vacuum), cranking at 10, idling at 15-20, WOT 28-36, cruising at 40+, you can see the "sweep" the rotor button takes.
The target is to have the middle of the curve centre on the terminal, so half of 30, 15 + 10 cranking = 25

So at 25 on the balancer, the rotor should be centred on the cap terminal.

Your own figures could be different to my example.

[tortuga]

And have phased the rotor using a cap with a hole cut in it (one inch hole saw next to plug 1)along with an adjustable rotor. Trigger timing is set at 34, max is 31, base is 19 all in by 2500. Box RETARDS...

Used the adjustable rotor to "Center" the spark on the terminal cap from rotor, its almost ALL on the terminal as dizzy degrees are half the crank degrees: so 12 crank degrees is only 6 rotor degrees which given about a 5 inch terminal radius is only 0.26 inches long pretty easy to center.

Also with MS on the plugs seem alot cleaner and low end seems slightly better...

[Gaz64]

That all sounds good Steve.

Yes, all electronic "advance" is a calculated value which ends up being a retard after the trigger event.

The trouble with a lot MS ignitions is they don't have the duration of HEI.

This is one of my favourites:
Pertronix Second Strike Ignition System

[tortuga]

Originally Posted by Gaz64

That all sounds good Steve.

Yes, all electronic "advance" is a calculated value which ends up being a retard after the trigger event.

The trouble with a lot MS ignitions is they don't have the duration of HEI.

This is one of my favourites:
Pertronix Second Strike Ignition System

CD-1

Id like to do a crank trigger just for the precision...

[Gaz64]

Originally Posted by tortuga

CD-1

Id like to do a crank trigger just for the precision...

Yes, I thought that is what you are using.
Yes, a crank trigger is the way, the distributor can then be virtually just the rotor and cap.