The Ford Barn - View Single Post

rotorwrench · 12-02-2015, 01:31 PM

Most plugs are designed per the manufacturers specs for length of reach, type of sealing surface between head and plug, and the desired heat range. If you want a colder plug or a hotter plug, there are designations for that. If the reach it too long, it can lead to detonation or after fire dieseling. If the gasket surface isn't the same it may not seal well or damage the faying surface. Almost every plug ever made has at least one step up or down for heat range which is reflected by the part number.

Champion H-10 is only one usable brand. Autolite, NGK, and Bosch all make equivalent plugs for the flatheads. Some are better than others. Fuel system problems or piston ring problems can also be the cause of sooty plugs.

12-02-2015, 01:31 PM	#2
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,440	Re: Spark plugs Most plugs are designed per the manufacturers specs for length of reach, type of sealing surface between head and plug, and the desired heat range. If you want a colder plug or a hotter plug, there are designations for that. If the reach it too long, it can lead to detonation or after fire dieseling. If the gasket surface isn't the same it may not seal well or damage the faying surface. Almost every plug ever made has at least one step up or down for heat range which is reflected by the part number. Champion H-10 is only one usable brand. Autolite, NGK, and Bosch all make equivalent plugs for the flatheads. Some are better than others. Fuel system problems or piston ring problems can also be the cause of sooty plugs.