351C Timing: Initial, Curve and Total

[351c1971]

To answer your question: The optimum advance curve for a given engine, application and octane is pretty much the same for any distributor.
The attached document explains the requirements and math for a 351c in detail. I hope this helps.

 

[Stanglover]

It didn’t take long for things to get over my head. I don’t understand what you mean here. Or is this something more related to the stock distributors?

Think of it this way, no matter what distributor you use, the total mechanical timing, initial plus crank, cannot exceed what the motor will tolerate. In most case with a 315C, that will be around 34-36 degrees. Therefore, if you take 14-16 deg. out for the desired initial, then the crank degs. can't exceed 20. On a Motorcraft or Autolite distributor, (same thing different name) the crank degs. are controlled by the limit slot that you see in the pics. The wider the slot, the more crank degrees are added. The number you see on the slot is half the crank degs. A 15L = 30 degs. a 13L = 26 and a 10L =20. On most stock 351C's, the factory initial timing was set at 6 degrees. The engine tag will show L (over) 6 (degs.) followed by the engine ID code. In my case that is K613J, 613 being the identifier for a manual trans.
Modern electronic distributors are not something I've used or even want on my car, but basically they do the same thing.
There are other contributing factors to timing YOUR engine that include compression, cam choice, carb, piston type (dished or flat top). All I quote is from my own experience with a stock distributor on a basically stock motor with 10:1 compression and a Melling MTF2 cam and a Holley 670 carb.
Hope that helps clears things up for you and not the opposite.

 

[HeavyCoupe]

To answer your question: The optimum advance curve for a given engine, application and octane is pretty much the same for any distributor.
The attached document explains the requirements and math for a 351c in detail. I hope this helps.

Think of it this way, no matter what distributor you use, the total mechanical timing, initial plus crank, cannot exceed what the motor will tolerate. In most case with a 315C, that will be around 34-36 degrees. Therefore, if you take 14-16 deg. out for the desired initial, then the crank degs. can't exceed 20. On a Motorcraft or Autolite distributor, (same thing different name) the crank degs. are controlled by the limit slot that you see in the pics. The wider the slot, the more crank degrees are added. The number you see on the slot is half the crank degs. A 15L = 30 degs. a 13L = 26 and a 10L =20. On most stock 351C's, the factory initial timing was set at 6 degrees. The engine tag will show L (over) 6 (degs.) followed by the engine ID code. In my case that is K613J, 613 being the identifier for a manual trans.
Modern electronic distributors are not something I've used or even want on my car, but basically they do the same thing.
There are other contributing factors to timing YOUR engine that include compression, cam choice, carb, piston type (dished or flat top). All I quote is from my own experience with a stock distributor on a basically stock motor with 10:1 compression and a Melling MTF2 cam and a Holley 670 carb.
Hope that helps clears things up for you and not the opposite.

Thank you both for explaining, I understand now and see exactly what you meant originally. I don’t know why I didn’t at first. And thanks for the explanation on 15L, 13L and 10L. I have the parts so I hope to get everything set up today. Might even get to drive it.

 

[HeavyCoupe]

Everything is timed, curved and good to go and I even go to put the first miles on the new engine. We are hitting 34* all in and she sounds mint. I did have a little dieseling on the last shutdown but there’s still more tuning to do on the carb and what not.

Thank you all for the help.

 

[jpaz]

If you’re getting some dieseling, check to make sure the transfer slots in your carb aren’t opened up to much.

 

[HeavyCoupe]

If you’re getting some dieseling, check to make sure the transfer slots in your carb aren’t opened up to much.

You know I bet that’s it. The throttle cable is kind of wonky. I think it’s in just enough of a bind that I have to stab the gas to get it return to idle as the spring isn’t stout enough. I was just looking at a Lokar setup for the throttle and kickdown. There’s definitely room for improvement, Lokar or not.
Edit maybe not transfer slots because it’s been a long time since I watched that Uncle Tony video, but I get what you’re saying.