fuel demand?

[Chryco Psycho]

I am not sure of this, just speculation.  If my carbs were running low on gas in the bowls at WOT, would it lean out the mixture?  Could this now lean mixture pre-ignite and cause knock?  Making it seem like timing, but really be fuel?  I feel as though I was pretty ignorant thinking a stock fuel pump could handle 550 hp. I also feel like its is my distributor cap.

If the carbs are starving for fuel it takes a few seconds to drain the bowls , if it is immediate then it has to be something else such as ignition
 For example I ran a 550 hp 440 through a 5/16 fuel line it worked for a while until I stepped up the carb & intake , I made a pass [1/4 mile] it it fell off at the top end 11 seconds into the run , the plugs were white so I increased jetting & the car fell off sooner & the plugs were still white  so the carb took 11 seconds to  supply more fuel into the engine than the fuel system could provide + drain the fuel bowls empty

[cudabob496]

I run a six pack. In fact just spent the last three days re-jetting all the carbs. I was running rich. I have a high volume mechanical fuel pump. I believe it's a mopar pump. I'm running 623 dynoed hp. I find that you need an AFR gauge to really dial in your car. Also, in my case I have to run some race fuel. If I don't run some good gas I suffer run-on and the fuel overflows the bowel in the rear carb when I shut the motor down and leave the car overnight. We have such bad fuel now-a-days. FYI. I am at 3500 feet in Calgary. I'm running 68 jets on the center carb and 84-84 front and 84-86 (86 throttle side) on the rear carb. I have Promax metering plates on the end carbs. I cruise at 11.5 to 12.5 at 2500-3000 grand. Idle at 13-13.5. WOT IS 12.5. You don't want to be lean at WOT. I removed the vapour canister and the flared gas lines and replaced with AN black line and fittings and don't suffer any vapour lock. Also running a 180 stat. My car is a beast and fires up when hot without touching the throttle. Also running 6 AL box with mopar electronic ignition. Hope this helps.

I solved my run-on problem by killing power directly to the small red wire going to the MSD box.

[jordan]

So it wasn't fuel after all.  My ignition died, again.  I figured since i replaced it a year ago, it was fine.  But as it continued to slowly die, it wouldn't run to full RPM, so I assumed it must be fuel this time.  Eventually it wouldn't take high loads and would fall on its face when I kicked in the outboard carbs.  I pulled my ignition, and put a orange box in just to see, and behold!  It can pull all the way to redline!  Not perfect.  But it is just a stock ignition.  So I am on the hunt for a new ignition.  Something that will talk to a Holley FI system for a potential future upgrade. 

It sucks that I am not trained enough to know the difference between ignition and fuel problems.  I assumed my ignition was good since it was recently replaced, so it must be fuel this time.  It sucks when new parts fail. I just want a badass car that runs good all the way to redline.  Am I asking too much?   GRRRRRR      

[xtopfuel]

sounds like ignition to me but cant see or hear it, unless you have a valve train float issue under quick accel

glad you found the issue