Originally Posted by iamtheari
Does the polarity work out so my cylinder 1 and 3 bottom plugs and cylinder 2 and 4 top plugs will be opposite, and rotating them will give that benefit even though the automotive plugs and E-mag donít get it? That would justify the split.
Lycoming firing order is 1-3-2-4 for four cylinder engines. Every other time the mag fires would be same polarity. Plug 1 and 2 have polarity opposite of plug 3 and 4.
With one EI (E-mag), you could have all EI plugs on the bottom and all mag plugs on the top if you want to do that.
When it comes time to rotate the plugs, rotate them to next in firing order. For what the automotive plugs cost, you may just want to install new ones.