16 and 21 weights in my DSII?!?



Well, I pulled my dizzy apart today and looked at the advance weights.

I have 16R and 21R labeled on the weights, with the 21R side engaged. Does that mean I'm pulling 42 deg of mechanical advance?!!

Well, I want to switch the sides but I'm wondering if I can get even smaller weights so that I can bring my total advance down to a reasonable level.

Does this sound right? Is it possible for me to order lighter weights for this dizzy?

Hey CC,

You should be able to get any weight you need. However, you may have to get the parts store to send you direct to their rebuilder. I have done this.

All the best - Steve

The Ford 2.3L distributor is set up the same way. Oddly I was gonna check my I6 dizzy since it is out of car. Thanks for saving me the trouble! :LOL:

Switching the spring from 21 to 16 deg shortens the advance curve and brings in full advance sooner, which is a good thing. This used to be a popular mod for Pinto's and Mustang II 4 cylinders. I am trying to bring it back on the 4 bangers so I would recommend it. It is a cheap and fairly easy performance mod. People pay good money to have done what you just did.

I would not try shortening it further though. Going from 21 to 16 is a good jump.
But doesn't having 16 weights give me 32 deg of mechanical advance? I thought I only wanted to have about 20* of mech so I can bring my initial up higher?

My car likes to run around 35* initial - with this setup I'm still getting too much mechanical.

You are correct. The 16* weight will give you 32* at the crank B4 initial and vac. Vac will be highest at idle, where mechanical will be very low (maybe none). Remember, mechanical moves up with rpm and is very smooth / predictable. So, at idle with your current set up (as I remember it) you have 15* initial, 17* vac, and 0* mech. However, at 2500 rpm (typical max mechanical point) you could be looking at an all-in of up to 15* + 17* + 32*. In my experience the only way the car could run with that much advance is with VERY low cylinder pressure, i.e., cruising on a flat road (no wind) or going down hill. Change your weight to 10* / 12*, put initial at 15* and disconnect (turn-off) the vac (yours is adjustable - right?). Then, if you still feel you need more advance at idle you can bring the vac back a little at a time. However, if you stay with initial in the 15* any amount of vac under load will probably cause ping.

All the best - Steve