Dave, that’s an email address. Not sure I follow your “package” recommendation?
Just sent you an emailSee that number at about the 7:00 o'clock position, it is a ZERO, 0, LEAVE IT THERE, DO NOT CHANGE IT. Mark the dampener.
You would have that info already if you had sent me your email request for the "vacuum advance stop plate information package" as I outlined.
It has how to do it procedures, and even pictures, so anyone can understand it.
Thank you for the picture of the dial, it will be included in the package, with a capitals "DO NOT USE THE DIAL BACK FEATURE ON ANALOG SYSTEMS".
Dave, I hate to disagree with you but that timing light pictured above came out long before EFI and computerized engine controls.NOPE, IT AIN"T, NEVER WILL BE ON AN ANALOG IGNITION SYSTEM. ONLY time the dial back is accurate is on an EFI setup where the EFI computer sets the timing curves, that is what dial back is designed to do, that is all it does, NOT ANALOG compatible...
I think you're really close to getting this resolved. I think ultimately you'll find that something in the neighborhood of 12* initial works great, then get your vacuum advance limited to about 10* total per Dave's instructions (with advance plugged in to full manifold vacuum) then use whatever bushing or whatnot is required to limit total mechanical advance to 36*-38*, and you're good to go.bumped initial timing up to 10deg @ 800 RPM and it’s steady. I’ll leave it here for now until I get a test drive.
Dave, I gotta disagree with you. Points setups and HEI units have lag in their systems, just like any other electrical/electronic system. Signals don't travel instantaneously, nor do voltage levels rise instantaneously. It's just simple laws of physics and limitations due to physics. Ya just have to design/build the system to compensate for those lag times, when possible.OK, here we go, yet again, and it is way past old.
When we speak of a timing system that uses mechanical, and/or vacuum advance timing curves, that is an analog system, and when the timing is changed by those methods, the points, or reluctor and magnetic pickup make a spark, no lag, no computation time, it makes a spark then, right then, not a millisecond later, RIGHT THEN.
Now, comes along "dial-back". Why do we NEED a feature that recomputes a timing signal on a system that does not recompute it in the first place? WE DON'T.
What is "dial-back", anyway? Well, it is a program inside a timing light to recompute the spark AFTER a computer, such as EFI used inputs and computes a spark for an engine equipped with that computer. The "computation lag" creates an inaccurate timing signal to the ignition components from the time it takes to compute the degrees the system would make, and get that info to the module to make the spark. So, a computer timing system does alter real world timing to the point it is inaccurate as opposed to the direct fire no computation lag of the analog system.
Dial-back un-lags the computer computation lag time.
So, yes, dial-back is well worth it to get the timing right ONLY ON A COMPUTERIZED TIMING SYSTEM, but not even close to accurate on an analog system, THAT DOES NOT COMPUTER LAG COMPUTE TIMING.
Sorry to burst the bubble, but that is the way it has been all along, and misinformed by many since the invention of computerized timing curves, and over hype sales departments for dial-back timing light sales companies.
Dial-back is quite easy to fix on analog ignition systems, LEAVE THE DIAL-BACK AT THE ZERO NUMBER, DONE, FINISHED, WORKS CORRECTLY FOR ANALOG. Simple as that.
Hi Dave,I sure hope you didn't check the timing with a timing light that has a "dial-back" feature on it that was set to read the EFI computer lag of the dial back, that is not accurate.