I've always taken these little buggers for granted but since I'm doing my own Condition Inspection I had to deal with them this week. Several things surprized me.
(1) The manual that came with my direct from Lycoming O-360-A1A does not specify what spark plug to use.
(2) The Aircraft Spruce catalog says the the REM40E is correct but my engine was delivered with REM38E (colder) plugs.
(3) The correct spark gap is not specified in (1) or (2).
(4) I found the acceptable gap range on a Champion web site as 0.016" to 0.021".
(5) All of my plug gaps were oversize by several thousanths.
I have a Lycoming factory [improperly] installed LASAR ignition system so that may require the colder plug. After I vibrator cleaned and abrasive blast cleaned and regapped the plugs to ~0.016" the engine ran smoother. OK the question - are spark plugs really worth researching to try and eak out some performance gains.
Bob Axsom
(1) The manual that came with my direct from Lycoming O-360-A1A does not specify what spark plug to use.
(2) The Aircraft Spruce catalog says the the REM40E is correct but my engine was delivered with REM38E (colder) plugs.
(3) The correct spark gap is not specified in (1) or (2).
(4) I found the acceptable gap range on a Champion web site as 0.016" to 0.021".
(5) All of my plug gaps were oversize by several thousanths.
I have a Lycoming factory [improperly] installed LASAR ignition system so that may require the colder plug. After I vibrator cleaned and abrasive blast cleaned and regapped the plugs to ~0.016" the engine ran smoother. OK the question - are spark plugs really worth researching to try and eak out some performance gains.
Bob Axsom
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