Join Date: Apr 2005
Location: Irwindale, CA USA
Joe, I'm sure you're aware that the MarelliPlex has a very short degree of advance - 12 degrees. The Shankle mod brings/brought it up to 17 degrees. So you won't be surprised when I double checked today that at 850 idle, the pointer was roughly 17 degrees from the 36 degree mark. The Alfetta didn't like it, didn't ping but would do brief cutting out when revving, getting worse once fully warmed up.
Bottom line after several retarding of the dist.and testings I ended up with the pointer at the 6 degree advance mark at 850 rpm. However, when I set the timing light on 25 (degrees) and revved it to roughy 3.5K (or more) it ended up on the same spot - 6 degrees (BTDC).
I'll add that I added a second washer to the spark plugs. I was (still might be) getting blow by through the spark plug hole and had the plugs tightened as much as I was comfortable with. I can't beleive that would have any effect to the car's running.
I'm still not completely happy with the results, but for now will drive it and make incremental adjustments if I feel they're needed.