318 Motor, please help
Why rpm is important when setting timing.
Let's assume the the timing is set at 8* BTDC at 1200 rpm using original distributor.
But if we measured timing at some other engine speeds the timing might look like the dashed gray line.
See how the timing at 700 rpm (the intended idle rpm) is much too late?
In contrast 8* BTDC at 1000 rpm with that same distributor might be OK.
That distributor was intended to be used with an initial of TDC.
The distributor you have may be different, but it will still have an rapide advance above the intended idle rpm. So when you slow the engine down, take another reading.
Why rpm is important when setting timing.
Let's assume the the timing is set at 8* BTDC at 1200 rpm using original distributor.
But if we measured timing at some other engine speeds the timing might look like the dashed gray line.
See how the timing at 700 rpm (the intended idle rpm) is much too late?
In contrast 8* BTDC at 1000 rpm with that same distributor might be OK.
That distributor was intended to be used with an initial of TDC.
The distributor you have may be different, but it will still have an rapide advance above the intended idle rpm. So when you slow the engine down, take another reading.