Sweet spot with new points

29spcoupe

29spcoupe

Well-known member
I have changed points many times and never had a problem. I noticed that the timing was off, so I checked the points and found the rubbing block had worn down quite a bit. I installed new points. Since then the 'sweet' spot had changed, so I double checked the points and found they were correct. Over-heating, unable to find the sweet spot I borrowed a New-Rex auto spark advance from my brother. I now have a completely different car! The coupe has never run this nice and before I know it, I am at 50 mph and the engine doesn't seem to mind. I think I will keep the New-Rex. John
 
I cannot remember where I read this but it said to polish the distributor cam to a mirror finish. It is important to lube the cam on a regular basis. There are several cam lubricants on the market but I just use some light grease. Ford, I think, recommended Valvoline.

The sweet spot depends on a number of factors including the compression ratio, the mixture, and how much power the engine is being asked to produce. I have always been able to find the sweet spot with my manual ignition timing, but I know that the automatic advance works best for a lot of people.
 
I know I am hijacking the thread but on the topic of distributor advance, I am feeling my way through getting the timing right on an engine I have had sitting here for a while. It has a 6:1 head which, I'm told means the ignition should not advance more than about 22°. I want to use one of the B distributors I have and they give 19-20° advance. Close! I thought I might set the timing a little advanced at zero revs. At what revs does the forum think I should expect to see the full advance on the distributor and how many degrees for say, every 100, 500 or whatever revs?
PS I have had a box of the original style points for years and then got more from a deceased estate. They all predate the current problem of the arm being the wrong length so I'd like to use them.
 
There is a discussion of the Ford garage and in it there is a chart compairing advance graph Nu-Rex and B distributors. It might answer some of your questions

I run a Phillips Auto Advance (which Nu-Rex reproduced) unit in my Town Sedan and love it. I limit total avvance to 29-30°.

https://www.fordgarage.com/pages/nurexadvance.htm
 
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Synchro909 said:
I want to use one of the B distributors I have and they give 19-20° advance. Close! I thought I might set the timing a little advanced at zero revs. At what revs does the forum think I should expect to see the full advance on the distributor and how many degrees for say, every 100, 500 or whatever revs?
PS I have had a box of the original style points for years and then got more from a deceased estate. They all predate the current problem of the arm being the wrong length so I'd like to use them.
Click to expand...

The B distributor, if timed using the A setting for initial timing (0°), will give a total timing of about 15° at about 2600 RPM, according to fordgarage.com. The slope of the timing curve is about 1.5° per 100 rpm.

Now that's their test run on their equipment. I have a B distributor that I'm going to get the timing curve on, but it'll be some months before I get to it. So your results may vary. But it would be reasonable to set 5-7° initial timing and try driving it.

I bought some B points from Third Gen recently, and they didn't have the arm length issue.
 
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