I am confused, do you use manifold or ported vacuum for the vacuum advance with a stock cam?

 

Thank for the help, you are always so good about answering my questions and I have one more. What is the distributor advance curve and where would I find it?

 

On your first inquiry. What engine are you talking about and what is the distributor? If you are using a Ford, engine/distributor combo say up to 1953 or possibly a bit later, it could be Fords "Load O Matic" which require a matched carb to distributor to work properly.
Cap

 

I am running a 1975 Ford 302 with the ford distributor & a C4 transmission

 

Is this the stock distributor?? Is it points and condenser or Dura-Spark??

If your goal is a good running, dependable engine, why do you want to mess with the vacuum advance?? Still assuming, this is basically a stock engine, why mess with the vacuum advance other than it's original way of operating? A quality Tune Up with Ignition and Carburetor all up to snuff should do that for you. Some Folks wanting to get a little more out of their engine will set the initial timing a bit more advanced than the stock setting. This involves road testing for spark knock or pinging when under a load and IF there is none and the engine starts effortlessly, meaning no kickback. Advance a bit more and test again. Some people do this using a vacuum gauge. Cap

 

I have stock engine with a stock distributor with points & condenser. I will driving this truck only once & a awhile & I am not looking for high performance. Thanks again for your help.

 

Sorry All, I don't know how to work the "Quote" thing.

FTZ HAIC, this response it to You about what You wrote below, continued below.

"The curve is basically how much timing is advanced from base timing, using RPM, vacuum or both to determine the advance, and how mild or aggressive the the advance is. Curves can be for power, emissions, or fuel economy. If it's stock it's probably economy, emissions or a compromise of both.

I didn't prefer using just RPM when I ran either of my F100's, but they were daily driven, and worth the mileage advantage using vacuum gives. RPM only doesn't take cylinder air/fuel loading into account, so you get the same timing low or high throttle. When you have vacuum hooked up:
1. More advance at light throttle, which gives you better cruising mileage.
2. Less timing at higher throttle, so it doesn't overshoot advance and get pinging.

RPM only advance is easier to setup, at the expense of part throttle mileage, and that can be an advantage if you don't drive it much."

FTZ HAIC, As a young man I would have to read a repair manual 2, 3, 5, 10 times to understand what they're trying to tell me. Then it would be, Oh blank, blank, blank now I get it. What You wrote above is clear as a bell, BUT I had to read it a few times, because it is a way I had never thought about before and I like, agree, with what you've said. Who says "You can't teach an Old Dog new tricks".

I'm going to experiment with on a 1968 F-350 with 360 2V, which is my daily driver while my 66 F-250 is in it's second preservation.

Thanks Again, Cap