I have just worked on our 13 engine and the flywheel brass mag clamp bolts are a finer thread than the repro bolts sent to me by Snyders. According to Snyders there is only one standard thread for these bolts. Has anyone else run into this problem? The bolt length and diameter are the same.
Try Lang's or one of the other suppliers. One of them should have the correct ones.
You posted before about this problem? Someone then suggested that your flywheel has been re-tapped to maybe 1/4" x 28 or 32, presumably because they couldn't find the right bolts last time the engine was apart. This seems the likely answer to me.
I have 2 1909/10 style flywheels in pieces, the early style with 'horseshoe' magnets and wired bolts in blind holes (so no peening). These are definitely 24tpi and I assume ASME #14 'cos I can't find a tap that fits.
I think you're going to be looking for a new flywheel or making custom bolts.
The correct thread size for T-3278 magnet clamp screw is 14 X 24 ASME.
Taps this size are available, but not common.
Ron the Coilman
Yes I did post this before, but didn't get much response.
You chaps have answered my questions this time, thanks kindly, great help.
I got a tap from my local Napa store.Told them the correct size and thread. They had one in their warehouse in Portland OR and ordered it in for me. Cost less than $5
Did you re-tap the fine threads to the standard threads?
This came up a couple of years ago. If I am remembering correctly, some repo ring gears were tapped with the modern size thread pitch, and repro brass mag screws were cut to fit these. These particular mag screws won't work with an original T flywheel with the original thread pitch (14x24). I got my screws from Snyders, and they were the right ones.( in 2006)