8V carb question?

[Joe-JDC]

I just finished one of my projects since retirement, and I have ported a C3AE-K 427LR intake, and a Performer RPM AG intake manifold.  The Ford intake will take either 660's or 750 Holleys, but I want to use Edelbrock carbs on the RPM AG.  I have Edelbrock 500 cfm carbs on one of my Y Block Ford 8V intakes, and they performed very well on dyno testing and matched the horsepower of the Holley's with in 2 or 3 hp.  I am asking if any of you have experience with larger dual Edelbrock carbs in the 600/650/750/800 cfm ratings?  I have all the QF/Pro Systems/Holley 8Vs, so this really will be an experiment to see if I can match the Holleys for performance.  The C3AE-K intake average flow is only 340cfm, with one port only flowing 336 cfm and 4 at ~360 cfm.  The RPM AG average is 405cfm, and all the ports are within 11 cfm of each other.  I have BT 8V, Ford TW, so this RPM AG looks very tempting as an alternative to the norm.  I am considering the 750/800 size for this dyno session.  Ideas or experiences?  (This will be on an all aluminum 468FE/TFS/HR/10.5:1 street engine.)  Joe-JDC

[Heo]

Friend of mine has a Chevy 468 with 2 Edelbrocks  The one in my thread about making the hole
in the hood
Dynoed 603 HP runs realy good he like them

[Falcon67]

I ran two 1406 - 600s - on my 302 tunnel ram with no issues.  I just did set of 500s for a friend, in order to get back my 600s that I loaned him  They ran so well on his 331 hemi/32 Ford that he wanted to buy them.  I did about the same on both sets - one step rich on pri/sec, or as close as you can get to that.  I drilled the shooters to around .035.  When they put the 500s back on the 331, they had to set the accel pump arm to minimum throw, so that's different.  Said the max throw was pushing too much fuel.  I would have rather put .031 stockers back on it to see how that worked.  But my friend is happy with the performance and I got my carbs back LOL.
 
The 600s have the accel arm set for max travel.  The 600s ran 1:1, but that car has 4.56 gear and a big converter.  The 302 is a mild motor - maybe 300 HP in good weather.  216/228 hydro flat, 9.5:1.  On the track the 60' was a tad softer than the go-to 650 DP and Air Gap but still sharp. MPH and overall performance was the same.  An added plus is that it upset the hell out of everybody (them ain't no Holleys!) ;~)

I think t would be interesting to try the 600s or some 750AVs on a larger - 351+ - type engine.  The later modes have some tuning for secondary tip-in that could be useful for drag strip performance.   I have not tried the 600s on my 351C - when our local track closed, that put the kabosh on my Friday night hours of experimentation.  It would be interesting since the 351C ram has fairly minimal plenum but rather large runners as you'd expect so pump shot may be the largest tuning issue.  And you have to pull the top of an Ed to change the shooters, so it take a while to swap on a dual carb deal!

[My427stang]

We dyno'd a 496 Tunnel Wedge with a pair of 600 Edelbrocks when we thought the 715s were causing issues (turns out it was an ignition problem)

Tied together, not progressive, the 600s Edels made 603 HP and 612 ft lbs, the Holleys made 608 HP and 606 ft lbs.  Odd thing is the Holleys were 200 rpm higher on each peak.  Could have been temp changes in the cell, how a progessive linkage presents itself,  or who knows, but the Edels did pretty well.

I have run many 750s and 800 Edels on things, but never dyno'd, they have all done well.  I think the cursed ones are the 500s, they others seem to do OK

[Barry_R]

I detest the 500 Edelbrocks. 
Miserable fuel curve in my testing.
But the larger ones will perform fine.

[Falcon67]

What I did on my friends 500s:
#1427 - .098 jet
#1445 65/47 rod (2 steps)
#1464 spring kit - Orange spring.
Drilled shooters - hip shot on size LOL.  Hammer to fit, bend to suit.

I forgot to mention that BOTH 500s did not open the secondary blades all the way.  Both required tweaking the linkage rod to get the blades 90 degree to the base plate at WOT.  Things were way off.  So look for that also.

Per Barry - yes, as those 500s sat on the motor, they sucked.  Stumble, stutter - you name it.  Junk tuneup.  Put the 600s on and it ran like a scaled ape. And that was a 331 Hemi with terrible idle vacuum and unknown internals.  Doesn't sound nor act like a high perf motor.   I was glad to make the 500s work well enough.  Wasn't sure they were going to work. 

I'll try to remember to look up the 600 specs tonight. 

[Joe-JDC]

Thanks for the replies and suggestions.  I decided to go for the maximum available with the AVS2-1912 800 cfm carbs.  I have two tune-up kits already for my other Edelbrocks, so hopefully they will be easy to tune as an 8V setup.  This way I can run them on any intake manifold and should be able to get dyno results that lets me know just how each manifold compares vs Holleys.  Joe-JDC