Engine is a 512 with aluminum heads, 10.5 CR. Initial timing is 20 and all in at 2,200 is 36. At idle, Six Pack hovers around 14.5 AFR. But while calmly cruising at 35/40mph, the AFRs are 12.5 driver side and 11.5 pass side, or richer. Center carb has 62 jets and 3.5 PV. secondaries are jetted 80/78 driver/pass sides with black springs. WOT and acceleration AFRs are in safe range 12.5-13.5. It’s the calm cruising AFRs that annoy me and I’m going to jet down the center carb to 60 and see what happens. But this seems so odd from the normal 440 engine settings of like 64 center jets and secondaries might be richer too. Therefore I’m struggling to make sense of my bigger cubic inch engine needing to be jetted down compared to a 440.
When cruising, I’m assuming the secondaries are not opening, but are they still contributing fuel via idle circuit? And it’s odd that the pass side AFR is richer especially if only running on center carb. I have the Innovative dual AFR setup so can read both banks.
Any thoughts of what I’m missing or not thinking about? But maybe the saying “tune for your engine and every engine is different” is what’s happening here.
When cruising, I’m assuming the secondaries are not opening, but are they still contributing fuel via idle circuit? And it’s odd that the pass side AFR is richer especially if only running on center carb. I have the Innovative dual AFR setup so can read both banks.
Any thoughts of what I’m missing or not thinking about? But maybe the saying “tune for your engine and every engine is different” is what’s happening here.
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