I just reinstalled my Dual Sync dizzy because I have never really been happy with the engine. I followed the instructions to a "T" from http://www.rancefi.com/HeavyGraphics...stributors.htm

When I started the engine locked the timing to 20 degrees I hooked up the adjustable Snap On timing light and to my horror it was up around 50 degrees. I did the process over again and it was around 50 again..

I loosened the dizzy and matched the timing light with what the laptop was showing. The engine runs and starts fine but I doubt the cam and crank sensors are phased right anymore.

What is the proper way to set the timing with the dual sync?

 

Sounds like you have the leading and trailing edge settings swapped or need to swap them.

If I read the instructions right it uses a Hall Effect Sensor. That is slightly different then the reluctor setup GM uses. The Reluctor setup GM uses generates a little advance as rpm raises, Hall effect switches don't do that. Dunno how you want to accouunt for that, or not, just a heads up.

 

I put one of these in my buddy's car. I did it just like the rance page said. It took a little to understand it but it did work after I was done. Remeber you are setting a cam signal that the computer needs to see 1 time per 1 revolution of the distributer. then you need to set the ignition spulse which needs to be seen 8 times, You do this on TDC, then turn the crank back to 30 then to 25 btdc degrees (takes the slop out of the timing chain) then the rotor phasing, just needs to be on #1 cyl. You should be within a couple of degrees. I used 25 degrees because that is pretty close to the total timing we run (forced induction) You want to use a timing number either in the middle of your curve or total if that is were you are going to spend most of your time. Does your harness have the white wire with the plug on it? Do not disconnect this if you are using the forced timing . I personally run my car in batch, same power. That distributer does make running sequential a ton easier if you don't have a jesel belt.

 

What those guys said is correct.

Those instructions are still good, but not quite up to date. If you have newer tuning software, just select "Dual-Synch" from the dropdown list of ignition types and skip steps 8-14. That way you can't get an edge wrong.

 

Grumpy was right..

Instead of pulling the dizzy to set the points I just rotated it, this works fine as long as you move the dizzy the oppisite way of the rotor, the edges were swapped..

All is fine now, thanks!