[thelastdon15]

I have a 350 chevy with camel back heads, edelbrock intake, lopey cam, headers, and a 650 cfm thunder series electric choke edelbrock carb. For a while it had trouble idling so my dad told me to turn the idle mixture screws out alot and it worked and now it has no problem idling. However upon testing it I ran into a new problem. When I floor it, it will make loud popping noises coming from the end of the exhaust. Any ideas on how to fix this problem?

[fast68]

that is most likely unburnt raw fuel exploding in the exhaust pipes


running too rich

edelbrocks are good for running rich

they were tuned and jetters generically from the builders

you have to jet them to be efficient with the engine you arerunning

but most ppl dont do this and end up wqith too rich of a fuel mixture regardless of all the fiddling you do with any scresws on the carb


i dont know the mathematical formulas for finding out the fuel needed for an engine basedon its volumetric efficiency total and figuring out the jet and and needle sizes needed for that
engine as well


someone here will though



jets and needles are dirt cheap from summit etc

auto zone can probably get them too i bet


when adjusting the mix screws you are supposed to follow the instructions

you have to turn each one out until ther engine speeds up a little and then do something else and you need a tachometer to do this so you can watch what the engine does exactly as you are turning the screws



good luck

[techinspector1]

Here's the owner's manual. Just go step by step and you'll get it dialed in.....
http://www.edelbrock.com/automotive_...ers_manual.pdf

[Irelands child]

With one of the <$50 Edelbrock tuning kits and the manual that Tech supplied and about two hours you can have that carb turn that engine into a purring lion - something I, too have to do soon before my eyes burn out from unburned gas fumes

As a note, Edelbrock carbs are notorious for crappy running with any amount of dirt so a really good fuel filter is a necessity.

Dave W

[red65mustang]

first....
you need to confirm and know that the ignition timing is atleast set in the correct ball park range for your specific "lopey" cam based on the actual duration....

(please post parts details when you ask a question,,,"lopey cam" tells us nothing)

here's a decent ign timing versus cam duration explained link:

http://www.gnetworks.com/v4files/bar...withimages.pdf

even a stock cam can be "lopey" if the base timing is not set correct for the duration due to a low Hg vacuum signal to the carb at idle,,,,and the idle screws are mis-adjusted....
do buy or borrow a vacuum guage {$34?} and tune the motor timing correct for the cam with a timing light first....
(spark timing versus cam duration controlled valves closing timing is critical)

a favorite ever so true, so often, quote:
"80% of all carb problems are in fact ignition timing and spark problems!!!!"

fair chance, once the timing is correct the problem will go away...

if not, then start sorting out the carb A/F mix with the link TechInspector provided...