The Ford Barn

Bob Bidonde · 11-03-2019, 08:40 AM

The point gap specification is 0.018" to 0.022". Considering the radial fits of parts that can affect the point gap, I deduce the following fits (radial clearances) are necessary for a rebuild:
Shaft to Bushings 0.0005" to 0.001"
Cam to Shaft 0.0005"
Cam Lobe Variation 0.0005"
Upper Plate Center Hole to Casting 0.001" to 0.002"

The fit that the restorer has control over is the "Shaft to Bushings" because the ID of the bushings is reamed to size. Notice that if all of these clearances become additive, the point gap tolerance becomes zero as the gap would decay to 0.018".

What are your thoughts in this scenario?

11-03-2019, 08:40 AM	#1
Bob Bidonde Senior Member Join Date: May 2010 Location: Long Island, NY Posts: 3,464	Distributor Part Fits The point gap specification is 0.018" to 0.022". Considering the radial fits of parts that can affect the point gap, I deduce the following fits (radial clearances) are necessary for a rebuild: Shaft to Bushings 0.0005" to 0.001" Cam to Shaft 0.0005" Cam Lobe Variation 0.0005" Upper Plate Center Hole to Casting 0.001" to 0.002" The fit that the restorer has control over is the "Shaft to Bushings" because the ID of the bushings is reamed to size. Notice that if all of these clearances become additive, the point gap tolerance becomes zero as the gap would decay to 0.018". What are your thoughts in this scenario? __________________ Bob Bidonde