Barry in St.Paul
Senior Member
I have had a Bratton's "B" distributor cam on my 'A, and just purchased a new Snyder's cam to rebuild a spare distributor, so I measured the run-out on them with my dial indicator while it was convenient with the lower-body in the vise. Just for fun, I measured an old original cam I had in the junk bag (probably the one I removed to put the "B" cam on a few years ago).
I was surprised by the results. Both the Bratton's and Snyder's cams are advertised as "precision machined", etc. etc. and improved performance. Here are the measurements for each of the four lobes on the three cams: (zeroed on first lobe, then recorded both low and high point for each lobe without re-zeroing. So, some variation also on the low-point, if that matters any)
Bratton's B: 0 to 0.0255" / 0 to 0.026 / 0.001 to 0.27 / 0 to 0.026
Snyder's : 0 to 0.265" / 0.001 to 0.028 / 0.0015 to 0.027 / 0 to 0.0255
original Ford: 0 to 0.025" / 0 to 0.025 / 0 to 0.025 / 0 to 0.025
I was surprised by the almost perfect Ford cam! Maybe the "B" cams are not quite as precise because more difficult to grind? (more complex profile??). I would think something like that WOULD be 'better' today with CNC grinding machines and such.
Anyway, debating about running the old Ford cam in my freshly rebuilt distributor, restored to original system with wire and original style point. Only question is that the old Ford cam has some minor pitting and wondering if that will significantly wear the points fiber-arm faster, and whether the thousandth or two difference between lobes in the "new" cams is really going to be noticable?
I also noticed the Snyder's cam has a matte surface, and comes with an explantory note saying it was bead-blasted to better-retain the cam lube, but seems pretty rough for a cam! The Brattons and Ford cams are highly-polished.
What do you think?
And, do you notice any difference between the 'B' cam profile and the original 'A'? They advertise it as hotter spark to keep the plugs from fouling, but with my 5.9 Brumfield head, not sure that is any benefit to me.
By the way, when I disassembled my current 'modern' distributor, I saw the same thing as Tom Endy noted earlier, with my 'wireless' lower-plate. It has burn marks on it, and I have less than 500 miles on the car! Back to the wire for me.
I was surprised by the results. Both the Bratton's and Snyder's cams are advertised as "precision machined", etc. etc. and improved performance. Here are the measurements for each of the four lobes on the three cams: (zeroed on first lobe, then recorded both low and high point for each lobe without re-zeroing. So, some variation also on the low-point, if that matters any)
Bratton's B: 0 to 0.0255" / 0 to 0.026 / 0.001 to 0.27 / 0 to 0.026
Snyder's : 0 to 0.265" / 0.001 to 0.028 / 0.0015 to 0.027 / 0 to 0.0255
original Ford: 0 to 0.025" / 0 to 0.025 / 0 to 0.025 / 0 to 0.025
I was surprised by the almost perfect Ford cam! Maybe the "B" cams are not quite as precise because more difficult to grind? (more complex profile??). I would think something like that WOULD be 'better' today with CNC grinding machines and such.
Anyway, debating about running the old Ford cam in my freshly rebuilt distributor, restored to original system with wire and original style point. Only question is that the old Ford cam has some minor pitting and wondering if that will significantly wear the points fiber-arm faster, and whether the thousandth or two difference between lobes in the "new" cams is really going to be noticable?
I also noticed the Snyder's cam has a matte surface, and comes with an explantory note saying it was bead-blasted to better-retain the cam lube, but seems pretty rough for a cam! The Brattons and Ford cams are highly-polished.
What do you think?
And, do you notice any difference between the 'B' cam profile and the original 'A'? They advertise it as hotter spark to keep the plugs from fouling, but with my 5.9 Brumfield head, not sure that is any benefit to me.
By the way, when I disassembled my current 'modern' distributor, I saw the same thing as Tom Endy noted earlier, with my 'wireless' lower-plate. It has burn marks on it, and I have less than 500 miles on the car! Back to the wire for me.
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