Instructions

Tools needed:

computer with excel
hand operated vacuum pump
Timing light
vacuum gauge
vacuum hose enough to get the gauge inside the car
tach
video camera or friend with paper and pencil

Mechanical advance Data

Use a timing light and tach. to record amount of mechanical advance at 500 RPM intervals.
Place this data in the Mechanical advance at RPM column in the spreadsheet (Red BOXES).

Vacuum pot Advance at InHg

Place a Hand operated Vacuum pump on the distributor vacuum line. Set base timing at 0 degrees and check and record vacuum advance at 0 thru 25 inHg. Place this data in the Vacuum pot advance at InHg column at bottom of spreadsheet. (RED BOXES)

Vacuum InHg at RPM

Take a drive with vacuum gauge and tach hooked up in side the car. The vacuum gauge should be hooked to the ported vacuum that goes to the distributor. Position a video camera or have a friend hold it so you can record the tach and the vacuum gauge at same time. While recording accelerate at a normal rate. (you can experiment with different levels of acceleration to see how it effects vacuum levels ) View the recording at home and write down the vacuum levels at RPM in 500 rpm intervals. Record this info in the vacuum InHg at RPM column of the spreadsheet (RED BOXES)

The spreadsheet will figure out the rest and plot a graph of the next page with can be accessed by the tabs at the bottom of the page. The spreadsheet helped me understand what the vacuum advance was doing during light and med acceleration and let me fine tune what hte advance would be a cruzing speed.

Initial Adv.

Place initial advance in red box