I have the paperwork with my adjustment kit but I am not understanding it properly.
When people say I have 20 initial what exactly does that mean and how is that obtained? Is it already built in the distributor??
I thought initially I was doing it with the sticks. EX. If i adjusted the gap with 18 stick I was thinking I then had 18 degrees initial but what I think you guys are saying is 18 + the 12 degrees I see at idle means my distributor has 30 degrees mechanical so if so exactly what is that doing for me??
How would I get the engine to have say 20 degrees at idle to help with my 245 @ .050 545 lift cam's idle characteristics??
TY Ron
You have three different timing adjustments (for lack of a better term).
Initial, mechanical and vacuum advance. They are separate but affect each other.
Your mechanical advance is what you change with the sticks. Whatever the number is on the stick, that will be the total mechanical advance you will have. Thats in crank degrees. The 18 degree stick means you have 18 degrees of mechanical advance. If you look at the sticks, you’ll see the bigger the number on the stick, the bigger the bump is on that stick. Thats because you are adjusting the stop that controls how far the weights are allowed to open. There is a “window” (for lack of a better term) where those adjustment sticks fit into. As that window gets bigger (bigger number stick) the more advance you get. Smaller stick, smaller window, less advance. RPM, size and shape of the weights, the springs and even the shape of the part that the weights open up against control when the mechanical advance starts and how slow or fast the weights open and add mechanical advance.
Initial timing is the difference between your total mechanical advance and your timing from TDC at idle, whatever rpm that may be.
So, if you used your 18 degree stick you’d have (at some rpm depending on the above variables) 18 degrees of advance. If you, at your idle rpm have the TDC line on the damper lined up with zero on the timing cover (it may say TDC on the cover) you’d have zero initial, 18 total and then whatever vacuum you add but I don’t want to go there yet.
Because I’m not sure if you have a damper that is degreed, a timing tape on the damper or a dial back timing light I’ll say it this way. Your timing cover has some marks on it. TDC and then usually marks that add up to 10 degrees before TDC and 10 degrees after TDC. Where the TDC line on the damper show up on your timing cover marks is your initial timing.
If you look at your timing at idle and the line on the damper is lined up with 10 before TDC then you’d have 10 initial plus at some rpm you’d have your 18 mechanical for a total of 28 degrees.
It gets confusing because some distributors have very light springs and that causes the mechanical advance to start at a very low rpm and you get to full mechanical advance very quickly. Some guys have their mechanical timing all in by 2500 rpm. That is considered a very fast curve.
When your engine is at idle and there is no mechanical advance starting to add timing, and you start turning the distributor you are adjusting your initial timing. And that initial timing is how much or how little you turn the distributor.
Let’s say you decide you want 36 total at XXXX rpm and your best educated guess is you will need 20 initial to get a nice idle. The difference between 36 and 20 is 16. That means you’d need 16 degrees of mechanical advance to get your total of 36.
You’d grab your 16 degree stick, set the advance mechanism so that it’s snug on the 16 degree stick, drop the distributor in and fire the engine. Then you would (at idle) turn your distributor so that at idle you see 20 degrees and you’d be done with that part and you’d drive the car or make a pull on the dyno to see if the engine really wanted those timing parameters.
Way too long. The short answer is your initial timing is what you add by turning the distributor at idle, your mechanical is whatever stick you use to set the “window” in the advance mechanism and your total is the sum of both added together.
Once you get the initial and total sorted out you then (if you want to) add in the vacuum advance. That’s a lot more to type so I won’t do it here.
I hope that makes sense.
