Removed the trans and mag coil ring recently and to my surprise there were no shims anywhere between the block and mag ring. Has anyone ever set up a proper magneto gap without any shims at all? I didnt think to check the gap before tearing down and dont want to bolt everything back up since I have to replace the ring anyway. My car would always run on mag but not start on it, I attributed it to the damaged winding but maybe it just had too large of a gap???

All engines and feilds are different some will need shims and some will need a lot of them in different areas. Measure it when installing, should be .025-.045 any where in that distance and they will work fine.

I found that reproducing the original( long curved ) shim worked best for me, saved a heap of time and came in at 0.027"gap all round.
It saves all of those small shim adjustments in 4 different spots......we all know what headaches that brings..

I'm guessing 100 years ago they had the same problems.

Pat If you didn't have shims to begin with, after any adjustments, you may find you'll need them now.

Good luck, the swearing will begin soon when re-assembling the trans/flywheel.

Best of luck David.

Pat,

What was the mag gap when you took it apart? It certainly could have been correct with no shims. A lot depends on who did the babbit job and how the crank was located when the mains were cut.

I've never seen a T yet that didn't need the big full shim. I've never had a problem finding them at swap meets.

Royce, As I said in my post, I didnt think to check the gap before taking it apart since I was replacing it anyway. But when I noticed there were no shims I just figured I would ask here If anyone has ever had a coil that didnt need any shims to get close to a correct gap. Was thinking this may have been my reason for not having strong mag output.

My '15 had exactly the right gap (.020" top, .025" bottom with the engine on its nose) with no shims. It is the result of a very good babbit / machining job and a very straight rebuilt coil ring.

One reproduction part that has never been made is a good single piece magneto shim. I too have a good supply from swap meets for my own use but there has to be a lot of people who are not so lucky or resourceful as me and Larry.

I have had one engine that didn't need a shim. (even a blind squirrel gets lucky once in a while)The big shims came in varying thicknesses. If you can find several different sizes,it helps.