BakerUSAF 86T/A

Sometimes, when i rev the engine from idle, say push it to 2200RPM from idle, i'll hear a popping noise. But it seems to only do that when the engine is still pretty cool. Today, i drove maybe 2 miles to school, put it in park, gave it a little rev to about 2000-2200 RPM and a popping noise came from the top end, and for the first time, a little smoke puffed out of the cowl hood, but only a little bit and it stopped. I have a Demon 750 Carb without choke and weiman high rise intake on a chevy 350. Could it be that i need the vac for the carb or do i have a problem getting ready to start? I know i need the vac because of cold start problems. I jus starting to learn about this stuff so please bare with me. Anything would be helpful, thanks.

duckmanquacker

Welcome to the site!
for starters you have the wrong carb for a street car. you really do need a choke on that thing. Removing the choke only gives you about 3-5 extra cfm, and is good for racing purposes only. If you go to your local dirt track and look at the IMCA stock cars you will see they are required to run a 350 cfm holley 2 barrel on all engines above 355 cubic inch. so all these people who try and say you must have X cfm for X C/I of engine truly dont understand the fuel requirements or how to properly tune thier engines. Both APEIRON and FIVESEVIN can give you some ultimate advice on your aplication. give them a PM after a good search through the site as your symptoms have been addressed before.

pancherj

When I hear of popping back through the carb, I think "timing retarded". Did you check your timing? Is this a Mighty Demon 750? If so, that is a lot of carb for a 350 unless you have some serious upgrades.

BakerUSAF 86T/A

Yes, my dad and i are going to be working on adjusting the timing also because i think when he drove it he noticed the same thing. Sorry i didnt list the specs.
The engine is 350 bored .30 over to a 355
im not sure about the crank or heads yet but i plan to look into it.
keith black flat top pistons gapped for N2O
.498" lift @ 292 Comp Cam
Weiman high rise intake
and of course the 750 CFM "Speed" Demon Carb
K&N Air Filter
B&M Mega Shifter with shift kit...

Like i said it does it once in a great while and only if i really get on it when it's cold. Other than that it runs very, very well.

BakerUSAF 86T/A

Yes like i said we're putting a choke on it very soon, and adjusting the timing. I was just hoping that it wasnt something that couldn't be fixed or worked with.