Freshly built 440 based 505” stroker build going to dyno in a few days. Just looking for starting recommendations for the jetting. I have read quite a bit on anything i can find on jetting on this setup, but i se some very different approaches. I’ll give a rundown of what i have and please give me your recommendations:
505”rb - 4.350” x 4.25”
2618 forged Icon piston
7.0” h beam rod
Stock 71 block line honed, bored .030, torque plate honed, clean up decked
10.9:1 compr
Comp hyd roller cam by Dwayne P
235 /241 @ .050”
.589” /.571” lift. 112 lsa. (Power brakes)
Stock (untouched) Cast Iron six pack intake
Trickflow 240 heads with cometic .027”
Fully rebuilt 1990 vintage dc carbs.
(Both metering plates had staggered jetting and stamped 35 (.093” dr / .086” pass)
Metering plates were replaced with quickfuel jettable plates. I installed 81 jet dr / 77 jet pass.
Center carb left at 64’s
Pvcr’s were staggered at .052” and .043”
Automatic 727 with 2500-2800 stall
3.91 gear
71 cuda all steel body and factory.
This is going to be a street car only but run hard frquently.
So, what jetting woukd you start with and woukd you keep it staggered? I know we will look at plugs after each pull, but just looking for the best starting point for this setup, because as you know, pulling these carbs off with the steel lines is a PIA.
Thanks.
I would start with what you have. You're right in the middle of what I ran on the dyno. I tried richer and I tried leaner. In short, despite seeing the changes in BSFC, O2, and mass fuel as you would expect, the power and torque numbers were all withing the repeatibility of the dyno.
I've run this set carbs on a mild 383, a hot 383, a mild 440 and a 500 similar to yours. It's surprising, for how often I changed jetting around in those applications, I settled on nearly identical jetting for all of them.
In another case, we ended up with slightly larger jetting all around. But this was on Impastato's dyno in Michigan and the engine draws outside air in. It was litterly 5°F outside that day. Plus the motor had open 2" primary tube headers and a cam with about 90° overlap. Even with all that, the jetting was still not that different.
