BOSS 302 Distributor Points Cam C9AZ-12210-A

[JohnSlack]

I have a distributor here that needs a Points cam the Ford part number is C9AZ-12210-A, The Autolite part number is DF-371. The distributor arrived with a cam that was apparently placed in a rotary head and machined flat every 45°. and they did a poor job of that as well. So I need one of these. Please contact me if you have one of these that is available. Thank you tutorial below.


As you can see the points cam on the left has a very rough finish, most importantly it is flat on every face. The distributor points cams are not flat on each face you can see the line in the middle of the points cam face on the right. This is as it should be to keep the points from bouncing at speed.


In addition as most of you have seen before there is a counterbore on top of the points cam that allows the standard rotor to be used instead of a special shortened version that would be another super rare can't find part for the BOSS 302, BOSS 429, BOSS 351 or 72 HO 351 cars.


Putting the points cam together with a standard one you can see that in addition to the counterbore the points cam overall height is taller than a standard part.

If you are buying a used distributor pay attention to the condition of the parts that are hard to find and expensive when missing. Thank You,



John

[shelbydoug]

I have the same issue. I posted for one  a year or so ago and wound up getting one from Perogie. As it turns out it is identical to the one that you are replacing. Perogie called it a "reproduction" and did not represent it as an original Ford part though.

It has the same "imperfections" as yours but in addition it had like .007" or .008" of play in the fit internally on the shaft which made it wobble and impossible to set the points accurately.

I think that I have corrected that by knurling the interior bore and reaming it to 5/16" but I have yet to try to run it.

If that doesn't work then that distributor will just become another display item in my shop (I need a bigger shop for that reason of overpopulation of displays) and will just go with some kind of an alternative.


Of all the parts I've needed that are rare, that cam seems to be the rarest? That says something right there.

In the process of searching, I did discover that although that series of dual point/dual vacuum advance distributors all use the same basic points cam, the advance notches are not the same and vary according to the application.

Whereas the B2 has a 10° smallest notch, the 351HO that I had was a 14°. The B9 and CJ's I've never had so I don't know which those used.


I didn't realize that the small rise in the middle of the cam was to keep the points from bouncing.

I don't remember anyone else ever mentioning that and I haven't read the Ford B2 "Off Road" booklet in years but seem to remember that it recommended using the 289hp dual point instead of the B2 for racing because there was no way to stop the B2 points from bouncing over 5,000 rpm's even when eliminating the vacuum advance and locking that out?


All part of my continuing education and my posting here is not to disrupt the purpose of your wanted ad but to add addition pertinent info to your tutorial. So hopefully you will forgive me for that?

Also the Perogie part was $125 which makes me wonder what the price would be for a genuine Ford or Motorcraft part but it might just be a better idea to get an entire genuine B2 distributor now? That also seems to be difficult as the majority for sale are very obviously re-stamped standard distributors that only look original?

As you suggest, further investigation of the unit you intend to buy is strongly suggested.


Point of order! You mentioned a special shortened distributor rotor? Does that actually exist?

One of the alternatives I explored was using a standard points cam but discovered that the height of the cam in relationship to the points block do not line up, so that was a no go as well.

[shelbydoug]

Here is a picture of the points cam in my '73 Pantera. It is a 351HO dual point distributor. Notice that the points cam does not have the small rise in the points cam like the Boss 302 version that you posted.

To the best of my knowledge, that is the original points cam in that distributor.

[shelbydoug]

https://www.ebay.com/itm/285107429727?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&mkscid=101&itemid=285107429727&targetid=2512152189032&device=c&mktype=pla&googleloc=9189605&poi=&campaignid=21214286338&mkgroupid=161030074701&rlsatarget=pla-2512152189032&abcId=9407521&merchantid=113750948&gad_source=1&gclid=CjwKCAiAudG5BhAREiwAWMlSjBsF6vAAysKK4ylFsQgLGkIxSzlC7cj_CVeR00vsWjrgPpc-19zpFRoCfCkQAvD_BwE

[JohnSlack]

https://www.ebay.com/itm/285107429727?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&mkscid=101&itemid=285107429727&targetid=2512152189032&device=c&mktype=pla&googleloc=9189605&poi=&campaignid=21214286338&mkgroupid=161030074701&rlsatarget=pla-2512152189032&abcId=9407521&merchantid=113750948&gad_source=1&gclid=CjwKCAiAudG5BhAREiwAWMlSjBsF6vAAysKK4ylFsQgLGkIxSzlC7cj_CVeR00vsWjrgPpc-19zpFRoCfCkQAvD_BwE

Thank you for the heads up, I had seen that one and can't get my head around why someone would need blast the part. The second part of the story I can't get my head around is why with a BOSS 429 distributor would you have to remove this piece to use a Pertronix ignition. So even though the price isn't bad... I'm not sure the part might not be bad.

[shelbydoug]

https://www.ebay.com/itm/285107429727?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&mkscid=101&itemid=285107429727&targetid=2512152189032&device=c&mktype=pla&googleloc=9189605&poi=&campaignid=21214286338&mkgroupid=161030074701&rlsatarget=pla-2512152189032&abcId=9407521&merchantid=113750948&gad_source=1&gclid=CjwKCAiAudG5BhAREiwAWMlSjBsF6vAAysKK4ylFsQgLGkIxSzlC7cj_CVeR00vsWjrgPpc-19zpFRoCfCkQAvD_BwE

Thank you for the heads up, I had seen that one and can't get my head around why someone would need blast the part. The second part of the story I can't get my head around is why with a BOSS 429 distributor would you have to remove this piece to use a Pertronix ignition. So even though the price isn't bad... I'm not sure the part might not be bad.

I honestly can no longer tell what is a good reasonable price or not? It depends on how badly you want it I suppose?

When I look at that ebay part, I'm not sure that it is original or not? These things are one heck of a mysterious part that few know enough about?

I just don't know enough to render an opinion.

In many cases we seem to just arrived at a point when even the sellers aren't sure any more?

With the picture that you posted of the original with the anti-bounce bump, I keep looking for others and that's even the only picture of it I can find. Strange is seems to be only the Boss cam with it?


Pick your reason/s for it being blasted but we don't know the condition it was in before.