I appreciate the input fellas. Based on everyone's feedback (I hope it's right), I'm leaning toward zero-decking and using a 0.039" gasket. This puts my static compression at 10.45 and dymanic CR at 8.25 - both quite a bit more than I was originally aiming for. The calculated cranking compression pressure would be 170 psi, which sounds doable considering my iron headed 340 cranks 165 psi and runs fine of 91 octane, even at high temps.
If that proves to be too much, I could always retard the cam. Retarding it 4* would drop the DCR from 8.25 to 7.98 and the cranking pressure from 170 to 163 psi. That's an option too I suppose.
Everyone loses their **** if they can’t run orthodox timing.
I’m saying that if you can make power and only use 31 or even 28 total (with the correct curve) you are FAR better off than with 35 or more.
You are reducing negative work. The farther from TDC (before TDC) you fire the plug, the harder the piston has to work to get to TDC. Thats negative work.
On any NA build the goal should be (one of the goals anyway) is to do everything you can to increase burn speed. That’s one of the things tight quench does. It speeds up the burn rate.
Also to note is that it reduces the tendency to detonate because any fuel that gets trapped out there is more prone to detonate.
Increasing compression ratio speeds up the burn rate and that’s a good thing until you can’t control it. Just like everything else you can find the limit.
Reducing air inlet temperature reduces the possibility of detonation, but in most cases we talk about here that can be difficult.
Reducing engine coolant temperature is also a big detonation reducer, but you can’t just drop the coolant temperature without doing other work, especially with a carburetor.
Blocking off the exhaust crossover if your manifold has one will reduce the tendency to detonate because that reduces inlet air temperature.
Of course, power adder engines are the opposite. You want to slow the burn rate. But that’s a different topic.
