Slick mag model number decoder?

[hifly]

Does anyone know of a slick mag model number decoder? For example, what is the difference between these:

4347 (impulse, for an O360-A1D)
4373 (impulse, for an O360-A1A and many O320)
4371 (impulse, many O320 and many O360)

More to the point, can I use a 4371 instead of a 4347 in an A1D?

 

[Bell206]

More to the point, can I use a 4371 instead of a 4347 in an A1D?

According to this, no. Looks like using a 4371 would need an STC.


https://www.lycoming.com/service-instruction-no-1443-r

 

[bnt83]

Does anyone know of a slick mag model number decoder? For example, what is the difference between these:

4347 (impulse, for an O360-A1D)
4373 (impulse, for an O360-A1A and many O320)
4371 (impulse, many O320 and many O360)

More to the point, can I use a 4371 instead of a 4347 in an A1D?

Different lag angles and one is for impulse coupling and the other uses a retard breaker

https://championaerospace.com/pdfs/techdocs/F1100/CAS3A_L-1318H.pdf

 

[hifly]

Thanks guys. I learned that the 4347 is a retard breaker mag, not impulse coupling mag. Slick/champion responded that the standard non-retard breaker setup is 4373 left (impulse) and 4370 right (direct drive) for the O-360 A1D. The 4373 has a 25 degree lag and the 4371 has a 20 degree lag. According to Slick, the 20 degree lag will work, but starting should better with the 25 degree lag (at startup fires at TDC assuming the mag timing is set to fire at 25 degrees BTDC)