ZZ383 Fast Burn Heads/Cam/ValveTrain...

[L31MaxExpress]

Had er out today. Hooked up camper as well. 5K (dry) down highway at 110km/hr (65mph) 3100rpm in 3rd locked up. Pulled great. IF I laid into er she would go.. trans temp 160. 2 small carb hiccups leaving a stop sign. I hit er & she stumbled a tad. I’ll talk to him on that. Un hooked works good. Do I expect more? YES.. he said if I’m not happy he will change the cam for free. I may take him up on that offer.....

Is the vacuum advance on manifold vacuum or ported? If its on ported I would switch it to manifold and see if the tip-in stumble goes away. Many moons ago on my G20 van with a 305, I fought an off-idle hesitation using what edelbrock called the distributor port on their 1405 carb for a while before discovering the difference in ported vs manifold vacuum. What works well for a true hot rod of an engine in a light car with a high stall converter or on a dyno does not work well in a heavy truck at full load. I had to back off the throttle screw a little and leaned the idle mixture screws slightly as well. It just idled and transitioned better with more timing advance at low rpm.

 

[Wheeler]

Figured out the issue... took a while but live n learn. The new HP Fuel Pump was over powering the Regulator. It was spiking to 15psi. He addressed that & boom idles without any hiccups. New gauge going on regulator to keep eye on pressure.

 

[Frank Enstein]

Is the vacuum advance on manifold vacuum or ported? If its on ported I would switch it to manifold and see if the tip-in stumble goes away. Many moons ago on my G20 van with a 305, I fought an off-idle hesitation using what edelbrock called the distributor port on their 1405 carb for a while before discovering the difference in ported vs manifold vacuum. What works well for a true hot rod of an engine in a light car with a high stall converter or on a dyno does not work well in a heavy truck at full load. I had to back off the throttle screw a little and leaned the idle mixture screws slightly as well. It just idled and transitioned better with more timing advance at low rpm.

That is my biggest carb tuning call I get. Off -idle stalling/hesitation.

Another carb falsehood "If the power valve is open at idle it will run rich" -My Buddy

My Buddy is an idiot who should have his tools confiscated and returned to Big Lots and be forced to date my ex-wife for a mandatory 6 months as penance. He will take his own life so we don't have to