The Ford Barn

wga · 08-07-2011, 09:24 AM

Ref: 8BA stock - with Pertonix ignition and coil. NGK B 4L plugs
stock ignition wires. Warmed up to 160 - 170 degrees.
Checked the timing at 550 RPM, vacuum line plugged, vacuum gauge connected at base of carb. At idle the timing consistently jumps a few degrees advance beyond the setting of TDC. Watching the vac gauge, it is at 18 in. vac., however the needle moves from 17 to 18 continuously.
(plug gaps set tight ?)
Compression checked at it is
1 - 140 5 - 145
2 - 140 6 - 135
3 - 140 7- 140
4 - 150 8 - 145

What causes the timing to fluctuate as it does?

thanks

08-07-2011, 09:24 AM	#1
wga Senior Member Join Date: Jul 2010 Location: Yorba Linda, CA Posts: 900	Erratic timing Ref: 8BA stock - with Pertonix ignition and coil. NGK B 4L plugs stock ignition wires. Warmed up to 160 - 170 degrees. Checked the timing at 550 RPM, vacuum line plugged, vacuum gauge connected at base of carb. At idle the timing consistently jumps a few degrees advance beyond the setting of TDC. Watching the vac gauge, it is at 18 in. vac., however the needle moves from 17 to 18 continuously. (plug gaps set tight ?) Compression checked at it is 1 - 140 5 - 145 2 - 140 6 - 135 3 - 140 7- 140 4 - 150 8 - 145 What causes the timing to fluctuate as it does? thanks __________________ Henry Ford designed the flathead without the aid of a computer.