Distributor Cam Screw

Jim Parker Toronto

Jim Parker Toronto

Well-known member
Does anyone know what the screw size is that holds the cam on the shaft. I've checked everywhere I can and can't seem to locate the proper size. Thanks in advance, Jim
 
This was discussed awhile ago. It is an odd size unique to the shaft and cam. I can't remember the size but I seem to recall the pitch as 30TPI, also no metric equivelant.
 
I have just checked. 30 tpi, but it measures 5/16". I have tried all combinations of new screws into old shafts etc and no matter what combination I have they all fit 100% as I suspected.
Another line of thought. Have you ever tried fitting a 30 repro dash lamp cap onto an original base. Just won't go by a minute amount. You would think, whoever made the repro caps would at lease get their measurements right. No way will I ever be buying any more repro caps, that's for sure.
 
Jim, See Snyder's page 146 in new catalog for puller stud part # A-12130-DPS $ 13.25 . I made my own , but my buddy Joe used the bought one. If you know someone with a lathe they can make you one.
 
Hey fordgarage, I found your comment most interesting. Are you saying that some reproduction shafts and cam screws are not .325-30? I find that hard to understand because machines which cut threads are very exact. Why would any manufacturer go through the process of making a thread size any different than what it should be?
 
leo said:
Hey fordgarage, I found your comment most interesting. Are you saying that some reproduction shafts and cam screws are not .325-30? I find that hard to understand because machines which cut threads are very exact. Why would any manufacturer go through the process of making a thread size any different than what it should be?
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Probably because it is easier to use commercially available cutting tools, which don't list .325-30 as a size. Another possibilty is that when they sized the part to copy, someone had allready hacked it up with the wrong size cutting gear. I have several shafts ruined by a previous owner/mechanic cleaning up the thread with them using a 5/16 32 tpi cutting tool. A lot of replica manufacturers copy a worn out part and the person getting the part replicated does not explain that it is worn and where it needs to be changed to bring it back to original size, so they end up with a new,worn out part.
 
I Mfg the dist pullers and stud if your looking for just the stud call SueAnn she can help. If your looking for a tap you would have to have it custom make.

Bill Stipe
 
Thanks Bill, just got my order from you last week. Could have shipped them both in the same package! Someone suggested that if I knew someone with a lathe, I could have a screw cut. Two weeks ago got my new to me (1965) Standard Modern lathe moved to its spot in the shop. I advertised the old one (1941 Revitt) and sold it in 5 hours. I cannot cut a 30 TPI on the new lathe, so I checked the old one. Sure enough, as it was going out the door, I checked the data plate, and it would do it! Who says newer is better? Other than that, I do like the newer lathe better....
 
"Commercially available cutting tools" for a job like this would likely be a Geometric-style die head, Swiss screw machine, or CNC lathe, all of which can easily be set up to cut an oversized thread of odd pitch (with 0.325" being an oversize of 5/16").

The major diameter of properly cut threads is usually about 0.005" under nominal, as the crest is truncated to avoid a sharp edge. 0.320" sounds just right to me for a nominal 0.325 thread.

Joe
 
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