Spark Timing for a T Head Motor that Fires 2 plugs per cyl.

[mikewest]

I am setting up a Delco Distributor that fires 2 plugs per cyl. I have a Sun Dist. machine and want to know if the points should be set so they break at the same time or one just after another. I was told once that one set should fire just before or after  the other set. And if so how many degrees? Thanks Mike

[Grimy]

Mike, most of us Pierce folk with those distributors set them to fire simultaneously given today's gasoline, although factory manuals did call for a few degrees' difference on the gasoline of the day.

[mikewest]

Grimy, That's what I wanted to know. Thank you for responding. I didn't think it would make a big difference being that the motors are run at leisure and not belted up to a sawmill...  Are you the one that asked me about the P/A 80 parts I have ? I still have them plus more not pictured.

[edinmass]

You set them to fire at the same time. Check advance curve while it’s on the machine. You still need to set the timing once it’s on the car. Check your hand retard/advance also. Most car will take more timing today with today’s fuels, but be sure you have a good motor if your going to run it more advanced than stock.

[Grimy]

25 minutes ago, mikewest said:

Grimy, That's what I wanted to know. Thank you for responding. I didn't think it would make a big difference being that the motors are run at leisure and not belted up to a sawmill...  Are you the one that asked me about the P/A 80 parts I have ? I still have them plus more not pictured.

No, that was my friend and house guest Greg.  I'll remind him later today.

[mikewest]

1 hour ago, edinmass said:

You set them to fire at the same time. Check advance curve while it’s on the machine. You still need to set the timing once it’s on the car. Check your hand retard/advance also. Most car will take more timing today with today’s fuels, but be sure you have a good motor if your going to run it more advanced than stock.

Thanks Ed!!! I appreciate your input! Mike