Does anyone know if there is an auto plug that is equivalent to the aviation UREM37BY plug?
On the last oil change, I switched over to the NGK BR8EIS plugs (8) gapped at .035". While there might have been a slight improvement, performance was still lower as compared to the UREM37BY aviation plugs. I am still seeing increases EGT's and lower CHT's with some power loss (relative to the aviation plugs). I am also seeing much more carbon in the cylinders with some dieseling on shutdown.
On my next oil change (or whenever I take the cowls off again) I'm going to swap out the NGK BR8EIS plugs (gapped at .035") and replace them with NGK BR8ES plugs gapped at 0.045" and see if there is any performance improvement. The test is based on this article:
https://www.sciencedirect.com/science/article/abs/pii/S0306261917300673