Total Mechanical Advance on a 72 Q Code

[likesoldjunk]

I've been cleaning up a '72 Q-Code engine to put into my '72 Mach 1.
which was rebuilt and bored out .01, but is otherwise pretty much stock.
Rather than screw around with the points, I'm putting in a Duraspark
unit from a '74 Torino.

I had the new distributer all apart, and was going to re-curve it for
performance. Literature I have says that an engine of that compression
should have a total mechanical advance of ~38 degrees.

My confusion is that the '72 specs call for 6 degrees initial, and an
autopsy of the points distributer used a 10L gap in the reluctor arms.

so (10X2)+6 = 26 degees total mechanical advance

Doesn't seem like enough.... Any comments ?

PS, I'm not worrying about the Vacum advance for now.

 

[67topless]

Check out this article on Ford Muscle:

http://www.fordmuscle.com/archives/2000/03/timing/

But the synopsis is the following:

..."The rule of thumb is that the higher the compression ratio, the less total timing it can handle before detonation, and also the higher octane rating it needs to control detonation. Low octane fuels ignite faster, thus require less timing advance. Conversely high octane fuel can handle slightly more advance. Dyno testing has shown that most small block Fords with 9:1 to 9.5:1 compression make peak HP with 38-42 degrees total advance. Engines with 9.5:1 - 10.5:1 run best with 35-38 degrees total, and above 11:1, should not go higher than 35 deg. total. When using power adders such as nitrous, super or turbo chargers, the timing should be advanced accordingly..."

 

[likesoldjunk]

Well... that supports my theory so far. The Specs say
that my engine started life at 8.6 to one, so it should
be ~38 to 40. Yet the factory setup (Assuming that
points distributer was the original)

 

[68RCodeConv]

4V Clevelands like LOTS of initial advance and a very quick timing curve. I recommend something like 12-15 initial (if your starter can handle it) and 35-40 total. The advance should be all in by 3000 rpm.

 

[likesoldjunk]

That makes sense to me, but I'm just having trouble
lining that up with the original equipment, which would
be 6 initial, 26 total.

Could you count all that up against smog equipment ?