Steve,
How about just remanufacturing existing discs and covers?
Randy.

Aaron (10/22/2020)

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Steve, what would it take to make new discs for those pumps.




Money :)

But other than that, we’d have to:
- reverse engineer a disc to make a print, which would be easy.
-manufacture the disc: also pretty easy with our modern CNC machines
-figure out how to machine it to flatness tolerances to generate a seal: probably a bit challenging
-figure out if there is a way to machine/recon old distributor caps to mate with new discs, or be forced to make new caps...which would be hard as they’re cast

Steve, what would it take to make new discs for those pumps.


Driving the greenies nuts
http://www.killcarb.com/

Tony Bullard (10/20/2020)

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The new radius is so the sharp edge wouldn't score the OD bushing as the disk is removed.





Seems legit. Radius on the edge of the disc would not help with lubrication. All disc lube comes from the fuel supply and I can’t see how the disc would care if it had a small radius on the edge or not.

Reducing risk if bushing scratch seems like most likely benefit.

I can’t say I’ve seen a disc with a radius on its edge, nor do I have any good documentation on all the SD changes. The SD pump I have in my garage right now has sharp edges, but just 1 data point

Randy Sallay (10/20/2020)

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I've had a few of these Cummins Single Disc Pumps partially disassembled, mainly to inspect the distributor discs. Most of them had some scoring, but one I got a couple years ago was in very good shape, with a mirror like finish. Most of the discs had sharply defined square edge around the upper circumference. But this last one had a radiused edge around the upper circumference. 
Could this be a remanufactured disc, with perhaps a product improvement added?
Could this radiused edge be an improvement for lubrication of the disc against its bushing?
Anyone see this before?
Steve?

Randy Sallay
The new radius is so the sharp edge wouldn't score the OD bushing as the disk is removed.



Tony

I'm guessing it's just a radius on the blank before it was ground and lapped.



You could send them to a good machine shop to get them cleaned up. 



Tony

I've had a few of these Cummins Single Disc Pumps partially disassembled, mainly to inspect the distributor discs. Most of them had some scoring, but one I got a couple years ago was in very good shape, with a mirror like finish. Most of the discs had sharply defined square edge around the upper circumference. But this last one had a radiused edge around the upper circumference. 
Could this be a remanufactured disc, with perhaps a product improvement added?
Could this radiused edge be an improvement for lubrication of the disc against its bushing?
Anyone see this before?
Steve?

Randy Sallay