14
« on: March 27, 2022, 09:30:43 AM »
Need help / advise on issue with a 482 custom stroker crate engine tune. I'm still getting a serious bog under load. I'm using a Quick Fuels Q-Series 750 with the following current settings. They are as follows:
Primary jet #74
Secondary jet#84 with jet extensions
Primary power valve #45
Secondary power valve: plugged
Primary nozzle: #31
Secondary nozzle: #31
Accelerator pump: 30 cc primary & secondary
Pump cam: Pink #2 position
Cam is a Comp Cams solid roller
Intake: .691
Exhaust: .702
Lobe separation 112 degrees
Idle set at 950 rpm with 9" vacuum. Vacuum increases to approximately 14" at 2,000 rpm (checked with no load).
When trying to get the car moving, I'm getting a terrible bog and a slight lean backfire, so I know I need to get more initial fuel with the accelerator pump and cam as well as increasing the primary nozzle. I'm think I need to go to the green cam #2 position and increase to a #35 primary nozzle. My question is do I need to change the power valve also or? I'm lost on how to best size the power valve. The idle vacuum seems like the #45 is OK, but I don't know if I should change to a #55 or #65.
The engine dyno #'s are very good, but it was dyno'd from 4,600 rpm to 6,600 rpm, so no info on low end.
Any help or advise is greatly appreciate. The neighbor are starting to get angry with the holeshots to get the car moving.
Thank you.
Don
gt350bp