davepl

I am building a 502 with an MSD2345 distributor (dual sync) and a BigStuff3 engine management.

One thing I don't know how to do is set the base timing. Only thing I could think of would be to use a timing light and rotate the distributor until the timing marks indicated the same thing that the BS3 thought it was commanding, but that's quite a hack.

Is there a better way to know how to install the distributor so that the BS3 gets the right timing offset?

Thanks,
Dave

markinkc69z

Rotate the engine until the balancer and pointer line up to what equates to your maximun expected timing + 10 degrees. For instance if you never expect to run more than 42 degrees then set the pointer at 52. Rotate the distributor so that the reluctor is directly across from the pickup pole. Some newer msd distributors also allow you to loosen the reluctor and set rotor phasing. If this is the case then loosen the allen screw on the reluctor so that it is just free of the shaft. Turn the distributor housing so that the rotor is just starting to approach the #1 terminal. If you're lucky the magnetic pickup will hold the reluctor in position so you can tighten it down. If not then line it up as above. Because you're setting the distributor in an advanced position for the ecu the rotor should not point directly across from the terminal.

The sync signal is not super critical. I normally will set it at 60 deg before #1 or whatever the BS3 manual suggests. The requires backing up the engine to 60 deg and removing the pickup holder so you can see where the magnet on the shaft is. The newer hall effect pickup with an led makes it easier. The led will go out when the pickup is aligned with the magnet.

Set your offset in the computer and then verify with the light after commanding a static timing number for broad section of the map.