Reply to "How to do the ignition timing on a mangusta"

Mikael,

Nope. You want 34-36 TOTAL advance with the vacuum connected and engine RPM's at 2500 or so. Total is a sum of initial, mechanical, and vacuum advance numbers.

Some advance units will give you much more than this. Distributors from the smog era will give you much more mechanical advance. With totals up into the 40's+!

I run my distributor with no vacuum connected. I run 8-10 degrees of initial advance and 26 degrees of mechanical advance. (Number on the cam tower advance mechanism X2.) All the advance is active by about 2000rpms.

The reason that the manufacturers did this, allow such high advance numbers, is so that when in times of high vacuum (off the gas pedal, going down hill...) the ignition would advance to allow better burn of the mixture....or some propaganda like that.... In a performance car, it can lead to more premature ignition or pinging at inopportune times.

If you want the car to behave properly, and still run the vacuum advance, you will definitely want to use the ported vacuum connection on your carb. Otherwise, a full vacuum will screw with your idle levels all the time......

Steve