Distributor Main Shaft Photo

[Joe C.]

Can someone post a photo of a SHP distributor main shaft which clearly shows the configuration of the "football" that the weights ride on. I just received a new one, and either my old one was brazed on upside down, or the new one is. Thanks in advance.

[Joe C.]

This Will Make It Easier

Both of these are reproductions. Which one is facing the right way and which was assembled with the "football" welded on upside down:

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Thank you.

[Wayne M.]

Re: This Will Make It Easier

These two are factory original. I took a while ago to show the difference on cam configuration and stamped numbers. The one on the left might be off a '263' ball bearing distrib.

[Harry S.]

Re: Distributor Main Shaft Photo

Wayne, my understanding, the one with 54 on the top is from a 1111022 distributor, a 63 fuel car.

[Joe C.]

Re: This Will Make It Easier

Thank you. Apparently, my old shaft was assembled correctly. The new one is assembled incorrectly.

[Wayne M.]

Re: Distributor Main Shaft Photo

Wayne, my understanding, the one with 54 on the top is from a 1111022 distributor, a 63 fuel car.

Harry -- just checked my notes; the 54 (underlined) on the autocam is from my service '66-7 TI distr. 1111157, Delco band dated 4K9 (Oct '74). The rotating pole has 534 CCW stamped on the underside. So my mistake, it's not from my ball-bearing distrib. (should'a checked my notes first).

The "247" is on my 1111267 Camaro OTC tach drive K66, band dated 9D14. The rotating pole is stamped 532 on the underside.

My hypothesis is that these football cams (like rotating poles and vac advance cans) were selected from a menu according to "best curve" for the application, and may appear on several different shafts and distributors.

[Timothy B.]

Re: Distributor Main Shaft Photo

Also want to add that #54 cam is used on the 300hp distributors in 1963 with the stamped #37 weights. It's a slow advance that provides 24* at 4600rpm. The weight base is stamped 724, I always thought the 24 portion of this number was the degrees of advance.

I have a 1969 over the counter TI distributor (LS-7) that has a 726 stamped weight base and it's spot on at 26*. My 67 has a weight base of 530 and it's spot on at 30* centrifugal.

Sorry Joe for changing the subject..

[Wayne M.]

Re: Distributor Main Shaft Photo

Also want to add that #54 cam is used on the 300hp distributors in 1963 with the stamped #37 weights. It's a slow advance that provides 24* at 4600rpm. The weight base is stamped 724, I always thought the 24 portion of this number was the degrees of advance.

I have a 1969 over the counter TI distributor (LS-7) that has a 726 stamped weight base and it's spot on at 26*. My 67 has a weight base of 530 and it's spot on at 30* centrifugal. .....

You could be onto something here. In addition to the two distrib's I mention above, I had a 1112021 with a 530 CCW stamped on the weight base; also have a 1111060 with 736 CCW; a 1111296 with 540; a 1112038 with 534 (same as my 1111157); a service 1111069 with 536 CCW; and my NOS ball-bearing 1111263 (OTC 1976 ?) has (again) a 534, same as two others with this weight base/rotating pole. Note in pic that the center hole is so large for the ball-bearing shaft (left), that it intersects the slot for the football tang (centrif. advance limiter thingy ).

[Joe C.]

Re: Distributor Main Shaft Photo

1111069 is used with 327/365 non-TI. This is limited to 24 degrees centrifugal advance, yet the weight base is 536, so "36" degrees cent adv doesn't follow.
In the photo of the two 524 weight bases, it looks like the slot in the upper one is longer than the slot in the lower one.
736 and 540 weight bases correlate to what? 36 and 40 degrees cent adv? There were never any engines made which take this much centrifugal advance.

Old tech SBC with slow burn cylinder heads deliver max power at about 36 degrees +/- 2 degrees WOT (initial plus centrifugal) spark advance. Old tech BBC take a couple degrees less.

[Clem Z.]

Re: Distributor Main Shaft Photo

GM used to put a rubber or plastic sleeve around the pin to limit the advance. these will melt on a race engine so back in the day we soldered a 3/16" copper tubing ferrel on the pin to prevent over advancement.

[Joe C.]

Re: Distributor Main Shaft Photo

The ferrule doesn't last very long, either. Just run it without a sleeve on the pin and braze-up/reshape the limit slot to the length you need. You can also bend the tabs of the advance weights so that the weights themselves contact the "football" and act as limiters rather than depending on the advance limit slot.

[Joe L.]

Re: Distributor Main Shaft Photo

My hypothesis is that these football cams (like rotating poles and vac advance cans) were selected from a menu according to "best curve" for the application, and may appear on several different shafts and distributors.

Wayne------


Definitely. These cams were usually not unique to a particular engine application. A few may have been but most were not.

[Joe C.]

Re: Distributor Main Shaft Photo

Thank you all, especially Wayne Midkiff.
I have located a properly assembled reproduction main shaft with correctly oriented "247" autocam on top.

[Gerard F.]

Re: Distributor Main Shaft Photo

Joe,

Not sure this is going to help you.

This is a picture of my 67 327/300 Hp distributor before I refurbed it (almost untouched). This is a 30 degree advance distributor, so yours may be different for your 65.


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