Engine Spark Plug Collection

How Mike Healy's gas engine became a diverse spark plug collection.

One Point spark plug
A Maco dual priming plug, typical of those often used on early fire trucks. When the petcock on the plug’s side was opened, gas was put in for priming. A primer line on the other side of the plug connected it to the vehicle’s cylinders. A pump on the dash was then used to get fuel to all cylinders simultaneously, allowing quick starts.