I think the remark was to illuminate the mechanical advance dropping back from say 10 degrees BTDC to say 4 degrees BTDC when put in gear, the less initial advance will make the motor drop more RPM when put in gear One of the accepted standards on RPM drop on initial timing and the mechanical ignition curve as well as setting the carb. up to idle on the idle circuit only is to have only 200 RPM drop from nuetral to in gear with a automatic trans that has a standard non racing converter, IE idles at 800 RPM in nuetral and drops to 600 RPM in gear The less initial advance you have at idle can lead to a bigger RPM drop if the total mechanical advance has to much in it IE if you have 13 degrees mechanical(26 total crankshaft degrees) advance in the distributor and you want to have 34 degees total advance you have to set the initial at 8 degrees BTDC, but if the distributor has 3 degrees mechanical advance in it at 800 RPM and drops 2 distributor degrees at 600 RPM you end up with 4 degrees initial in it at idle, most motors don't like to have 4 degrees advance at idle They do like 12 to 16 BTDC though at a 600 RPM idle speed Is that clear Lots of ways to make are hotrod motors run better, but it requires working on and modifying some of the parts to make them better



Im pretty sure I follow you on what you mentioned. With that being said, I've always been stumped why the RPMs dropped so much with it in gear. I have already welded up the weight slots in the distributor so that it gives me 20* at the crank.

Now if Im following you correctly, because of my specific set up. When Im setting the initial with the car idling in park at say 11* and then put it into gear it may change that 11* to 5* because of the load now on the engine. So instead of 11* I should have 17* so that when its in gear its now at 11*???? Or there about?