Carb issue?
I reread the posts and your calculations are based on a flat top piston. I only mentioned kieth black pistons, but not which ones(23cc). I read the 12-1 compression ratio again and thought no way could I be that far off. Punching in the numbers on the wallace calculator with the cam i get the below information. Now i may have done something wrong but i think this is more accurate. A 12-1 cr will not run at this altitude on pump gas and i was building a 10-1 cr motor.
Static compression ratio of 10.1 :1.
Effective stroke is 3.60 inches.
Your dynamic compression ratio is 9.19:1 .
Your dynamic cranking pressure is 158.48 PSI.
V/P (Volume to Pressure Index) is 176
When you said Zero-deck,yes, I assumed flat tops .
I bet you entered the .050 Ica spec, Didn't you.
The Wallace is not set up for that; you have to calculate and enter the advertised spec. which then comes to;
Static compression ratio of 10:1.
Ica of 81*(see bottom of page) @6900ft
Effective stroke is 2.64 inches.
Your dynamic compression ratio is 6.94:1 .
Your dynamic cranking pressure is 100.49 PSI.
V/P (Volume to Pressure Index) is 82
and if in fact you are at 6900ft with just 10/1, then with the Ica of 81*, that engine should present as being extremely lazy at low rpm. I know of no bandaid for this condition.
Furthermore this would be another, perhaps the biggest, reason that your throttle needs to be so far open to idle. The engine is just not making enough power to idle at a more normal throttle opening.
I highly recommend that you do a compression test ASAP!
With a fully charged battery and the carb at WOT, crank as many times as it takes to get two consecutive same/near same, pressure readings. Warm is better than cold.
For a streeter, Static compression ratio, as a guide to building an engine, is as good as useless.
For a streeter, the predicted cranking cylinder pressure, is a far more useful tool. With alloy heads, it is possible to run up near 200psi, still on pump gas. My engine has run up to nearly 200, and the current combo is a tic under 180, still running on 87E10 at full timing/full load @930ft elevation.
Here's how I figured your Ica from the advertised of;
308/318/112+5
(1/2 intake duration, less the installed centerline, plus 360) less the intake duration, less 180, and finally sign change equals the Ica.
Here's how it looks in scientific notation;
let
Aid be advertized Intake Duration (308)
ICL be the Installed Intake Centerline (107)
Ica be the Intake closing angle
Ica=[(Aid/2-107)+360]-308-180, signchange= 81*