Tuning My Edelbrock 600cfm

[jwykes]

hey guys
so Im really good with holley's, especially the truck/street avenger series
however im having some issues with my new edelbrock 600cfm
does anyone know a good site to find this? I dont really feel like paying $30 for a book, when im sure a ton of people here have tuned them up
it seems like I get a little hesitation off the line when at wide open, and it somewhat flat lines around 4000rpms
so what im wondering is, can I swap out pump cams, how do I adjust the floats, should I be looking at jets...im roughly 2700 ft above sea level, anything else?
I know my timing is all good, and fuel delivery isnt an issue, its just getting the carb to send that right mixture
ive already adjusted the idle mixture...with a vacuum gauge and what not
so any help would be great

[jwykes]

oh its an
Edelbrock 600cfm (im not sure which series)
4 Barrell
Electric Choke
Vacuum Secondaries

[LXtasy]

Search on edelbrocks website. Only way I know of to adjust it is with the front idle mixture screws. What fuel pressure are you running?

[jwykes]

when I picked up the carb, I believe it said 8 psi..either way I got the regulator that went with the carb
and I have checked the site, and its all like "buy this DVD" "order this book now" so thats what turned me here

[jwykes]

Its the Performer, just so everyone knows

[bgfshjr]

im run'n that carb and i have the book i could send u pictures of the pages if that would help.

[SH-60B]

You've got jets, metering rods, metering rod springs, the accelerator pump shot. Try to download a manual.

[LXtasy]

Back the fuel pressure down to around 5.5 psi and go from there. 8 is way to much. You are drowning that carb in fuel.


http://edelbrock.com/automotive_new/...ers_manual.pdf

[jarrodh]

check your plugs, for the mixture, but the hesitation is when you stand on it??

if it is, then try increasing your initial pump shot..

[jwykes]

from a dead stop, if I put it down it'll hesitate for a brief second then get going

[jwykes]

ya if you could upload those pages that'd be awesome

[LXtasy]

Its a pdf file format. Wait a minute for it to load. Mine did the same thing and I fixed it per the link.

[BlazingSaddle]

That hint about lowering the pressure is a darn good idea. Floats don't like much over 5 pounds on those. Do you realize this is an "economy"carb? Not intended to keep up at higher rpm. Thats where the initial flat spot might come from. Good carb for normal driving once you get rid of the initial bog. Timing and accelorator pump shot do have something to do with it, but fuel pressure is the sneeky problem.

With this carb, I have always thought that if I could only increase fuel pressure at about 3500 and up, it would be a good carb. I do not believe you can do a simple tune to fix this and still keep this carb as it is. In other words, it will no longer live up to its "economy" billing and you could have bought any other carb by then.

If you can tune your timing to come up just BEFORE the carb, rather than off the carbs vacuum, you'll have the little bog solved, even if pressure is kept higher. But I do think you'll smell gasoline over 6 or7 pounds of pressure as it ages.

[jwykes]

so for sure, first thing...regulate fuel pressure?

[jwykes]

I know its an "economy" carb, but not by much, just a touch leaner

[SH-60B]

Move the linkage connected to the accelerator pump to one of the holes closer to the carb body. See if that helps with the off-idle bog. Check for vacuum leaks too. Are you sure the choke is all the way open when warmed up? I have used this carb before and I remember going a jet size richer on the secondaries but it wasn't about a "flatline" at any RPM. That might be the cam going past max torque. Weak valve springs can cripple the motor too.

[jwykes]

well the motor is "tip top" its all brand new, only about 4800km
so the pump cam is adjustable on this carb?