Mr. Fixit
Member
Hi All,
I need to seek the advice of some of you pro engine builder/tuners. I am having issues with properly tuning and have a stumble/flat spot during mild accelleration. The following are the components of the engine.
SB 350 bored .040 over
Flat top forged pistons
6" forged rods
Comp Cams Extreme Energy advertised duration 294/300
2 - Holley 4160 450 CFM carbs.
I have set all of the floats correctly and adjusted the idle mixture screws using a vacuum gauge. It seems that the best fairly steady vacuum that
I can acheive is -5hg with the idle mix screws set at about 1.5 turns out.
Is this -5hg somewhat normal for what I have described? The idle circuit seems fine and it runs very strong when throttled in park, but as I drive off, it generally stumbles slightly but rarely stalls, and does the same while accelerating while crusing at any speed. I havent checked the power valves to determine what rating they are yet either. Any thoughts, suggestions or next steps would be greatly appreciated
I need to seek the advice of some of you pro engine builder/tuners. I am having issues with properly tuning and have a stumble/flat spot during mild accelleration. The following are the components of the engine.
SB 350 bored .040 over
Flat top forged pistons
6" forged rods
Comp Cams Extreme Energy advertised duration 294/300
2 - Holley 4160 450 CFM carbs.
I have set all of the floats correctly and adjusted the idle mixture screws using a vacuum gauge. It seems that the best fairly steady vacuum that
I can acheive is -5hg with the idle mix screws set at about 1.5 turns out.
Is this -5hg somewhat normal for what I have described? The idle circuit seems fine and it runs very strong when throttled in park, but as I drive off, it generally stumbles slightly but rarely stalls, and does the same while accelerating while crusing at any speed. I havent checked the power valves to determine what rating they are yet either. Any thoughts, suggestions or next steps would be greatly appreciated