I have gremlins

[4speedTerror]

Ok my 496 has been running for about 2 weeks. And have kinda beat a dead horse here on the boards, but one last time.

When i started it up for the first time i had the initial timing to 12. Well after driving the car it seemed sluggish, especially since i knew what it is capable of. So i up'd the timing and was trying to make it detonate, and then go back a few degrees. So around 22 initial timing the motor ran like it should, and ran hard. So obviously my timing tab was put on wrong.

So now the motor runs really well, except when i go to floor the car. There is a slight hesitaion then the motor opens up like it should. I have heard that with to much timing a motor will fall on its face.....but i dont think that is the case here.

496
11:1
294 - 540/560 Retro-roller
Pro TopLine Heads 2.25/1.94
Demon 850 Mechanical
Single Plan Hurricane
Angus roller 1.7's

The only other thing i can think of is that i am sucking the bowls dry, and my fuel pump isnt keeping up.....can the motor drain those bowls that fast?...i mean this hestitation is measured in nano-seconds......Or do i just have some more carb tweaking to do?

Thanks fellas

[poncho62]

I think you need a bit better shot from your accelerator pump.

[383 chev]

idle mix screw sound a little lean to me 22 degrees timing at idle wit 11:1 comp is about right timing tab is not off for that matter if you have about 14 more in mechanical you alright unless u also have vacumm to go with the mechanical u could have another 14 degress there then whoa those two 14 degrees are for engine that have less comp and can handle less base timing!! this as been all my experience with my 11:1 406

[HWORRELL]

I don't know anything about the Demon carbs,But 850 seems big to me, you sure that thing ain't dumpin so much fuel when ya hammmer it that it puts the fire out ???
seen lotsa guy's have the same type of problem with too biga carb on the street.
example when I ran big block circle cars
The shop that did the Alky Holley specified
650...... Those big carbs are fine for drag racin where ya never drop the rpms.....
But ya need to check what the other guys said as they are all good suggestions..