conway62

Is anyone using an Edelbrock performer carb on higher HP engines? I am having a bit of trouble tuning it on my 454. Should I just forget it and go with a Demon or a Holley?

gkull

I ran the 750 EDelbrock for about 10 years. What specifically is your tuning issue?

69Rat

I have one on my 454.. though mine is only an LS6 spec right now. What sort of problem are you having?

conway62

The carb seems to run lean at about 3000 rpm and above. Idle is very rich. I have tired rod and spring combos but nothing seems to make much of a differance. I have the tuning kit and have spent a weekend so far trying to tune. Any suggestions? My 454 is a 480 HP crate engine with a compcams 268H cam. It farily mild. I have 15hg of vacuum at idle. The car runs fine until about 3k and then starts breaking up and pops a bit out the exhaust. :hurray:

69Rat

Hmm.. I bought a tune kit from Ebay for mine, and it worked get.. it's still a bit rich at idle, but runs like a champ! Mine is an LS6 build 454, so it has a good bit more cam then what your running. My biggest complaint is I'm a bit high on compression, so I have to run octain boost, or it pings and I have to retard it like crazy! :rolleyes:
Once I get my new L88 long hood on, I'm switching to the Edelbrock RPM manifold and cam kit. I heard it drops your compression a tad. It that doesn't do it, then I'll get the RPM aluminum heads.

:flag

gkull

Which spring color are you using and what are your present rods and jets. Do a search on this forum and someone posted a spread sheet of the total flow area of every rod and jet size in order.

The book and those tuning kits give only a few choices. If you look at the area of jet minus the area of the rod you will understand the relationship.

In cruise mode the rod is down and using the thickest diameter to restrict flow through the jet. on loss of vacuum at wide open throttle the spring lifts the rod to it's thinner diameter. less restriction on the jet flow making the air fuel mixture richer.

you need leaner on cruise and richer on power.

BSeery

You can get the total flow area data from the Edelbrock web page. It will show flow area for jet / needle combos.

pillowmeto

I have a 600 performer, i paid only 100 bucks for it with about 20 miles on it so i cant compain, it works right unlike the quadrajet. But personally i dont like them much, why, they die on turns and hard braking so i can only imagine what that is doing for my acceleration. Ill go with a holley or maybe even davinchi, but thats cause i like the best i can get so when i get somethingi save up for the right part, but now iim just getting a little from my L48 so i got a new cam to go in. A 427 w/ fuel injection woudl be my dream, ill prob save up for a few years and buy one, im still in college.

MAtt

MAtt

OkieVett

Switched from an Edlebrock to a Demon on my 350, very happy with the difference, feel a slight power increase, better driveability and idle

AlwaysWave

I saw the same trends with my 350. I drilled the air bleeds larger. Be sure that the transistion slot is not more than 040" exposed below the throtle plates.

Tominator

Sounds like the jetting isn't large enough, try increasing the secondary jets up a couple of sizes.

One of the biigest complains I hear about the edelbrock is they starve you for fuel at higher RPM, but with proper jetting that problem goes away.

gdh

I can attest to the above stmt. Where my holley (4779) would pull strong through 7000 rpm, the Edel Perf. (750 mech dp) seems to just run out of steam above 5300 rpm. After reading prior posts on this topic that can explain the seat of my pants feel of a loss of at least 30 hp with no other change other than to advance the cam 8 degrees.