40 degrees initial!
The reason it needs a lot of timing is because the mixture isn't that good and requires more time to get the flame front moving. When the mixture is less than ideal it requires the energy to heat the mixture to get to a point where it will burn. Energy that is used to get the rest of the combustion going is wasted instead of pushing down on the piston.
What was your total timing with 180 psi?
32/34 for power. (alloy heads)
50 for cruising at 2800, plus the dial-back as might be allowed.
45 at 2000, plus dial-back
The dial back is usually set to +6/-9
The Vcan brings 22* set ASAP
Idle-timing is 14, plus/minus dialback.
When the engine is cold, I dial in the +6 for a faster,cleaner, more stable, idle
When I dial out the -9 at idle, I get down to ~5* without changing the "perfect" T-slot setting, so she will idle down to 550/500 with the 230* cam, and that allows down to 3.5/4 mph parading.
When I dial up +3 to +5 for power;on the street, WOT power change is undetectable;
but the Part Throttle down low becomes a lil jumpy at small openings, with my manual trans . I just reach over and dial some timing out,to reduce the EFFECTIVE cylinder pressure, and she settles right down.
For those who want to know, my DB is an old Jacobs unit from the early 2000s. It has a built-in amp for the magnetic trigger, and also has a dial-back rev-limiter, which I use as a cruise control,lol. It seems to be good to well past 7500.
@Hysteric
I hear what you are saying, and do agree. But I'm just telling how I got 32mpg with a 223* cam in a 367. For this exercise I used a 600 model 1850, and just leaned it out and poured timing on it to keep it running,and geared it to 65=1650/85=2040.
To do that, I collected a series of very thin wires from IIRC about .006 to .012.. Then I accessed the IFRs, which were at the top of the wells, and did what I had to, in terms of leaning it out. I used the dial back to determine the timing she liked, centered around the cruising speed, and built the curve accordingly.
Since the secondaries were disabled, this could have been done with any 2bbl, and even easier with a meteringrod carb. This was a spur-of-moment exercise,done for a specific roadtrip; the engine was already making great mileage with a 750DP; I just wanted to see what could be done with the old 1850, that was gathering dust in the shed.
Since then, I have obtained a Dual-Port and a small TQ, and one of these days, maybe ........... I'll get around to doing something, but I thing this present world wwill fade away first.
