We've had a few folks install CPI, CPI-2 and EM-5 ignition systems on Lycomings equipped with the generally loathed and mistrusted Bendix Dual Mags.
We had a solution for the last 2 years to block off the old mag hole/shaft bore in the rear case but no way until now to make that spot useful for mounting a coil pack there as we did with "normal" twin mag engines.
Some of these Dual Mag engines have a pressure fed oiling hole for the mag bearing which needs to be blocked when the mag is removed and they come in 3 different bore sizes- .690, .750 and 1.00. Our Dual Mag covers have an O-ring sealed spigot which projects forward from the cover plate to block the oiling hole.
The new part below plugs the holes and also allows mounting of our coil pack in the previous space.
On wide deck engines, we can mount the 2nd coil pack up on top of the case. Narrow deck engines would have to mount the other coil pack either on the firewall or engine mount tubes.
We do need to know the ID of your bearing bore to ship you the correct spigot to plug off the oiling hole. Note that not all engines have this oiling hole present, in which case you can use our standard coil cover/ mount.
In some cases, it may be possible to mount both coil packs in the single mag hole but on some rear covers, there are other items projecting aft, preventing this.