My Chevelle build and spot to Rant

The Edelbrock 600cfm Is great for mild performance John.
Even works nice on 450-460 ci Big Blocks.
Gives excellent fuel economy with highway gears up to 3.25.
The Isky cam you have wants to breath deep.
750 cfm better match & I would tune with it.
Isky just makes torque everywhere. Even the Race Hot grinds.
They need Cfm air in to work correct.

Thats what I was thinking also Brian just wanted a more experienced opinion. I feel tuned right it is gonna scream and think installing the proper step-up spring will eliminate that popping. Right now it fires up like a new car two quick pumps to activate the electric choke turn the key and instant start. I will pull the electric choke off the 600 and install on the 750 also. There power still to be had out of the current setup. It even highway cruises ok with converter locked up at 1200 rpm. Wouldn't win no races at that rpm but its nice to be able to hear the radio on the ride to work now and again.

There may be a slight off idle Bog using the 750 Edel John.
Try and run 10-12 Degrees BTDC. Have full advance by 2,000-2400 rpm.
Will mask the bog pretty nice.
The off idle transistion circuit is not real sophisticated in E carbs.
They did a much better job on the 1980's-1990's Carter AFB Race series carburators.
There hard to find today.

Strictly Attitude said:

Thanks Brian hope you have a good day.

Click to expand...

I made it Ok John.
Hate moving my old Snap On tool box around.
Packed full of tools & real heavy.
Trailer used again today.

Mechanics have it rough like all today.

Grrr Stupid coil shit the bed forced me to pepboys to buy new one. Closest to my job where it happened. Will pick up the 750 tonight and a calibration kit tomorrow and a msd distributor kit. Will also grab my wideband and get that hooked up.

Well picking up an edelbrock spring kit during lunch along with a msd distributor bushing and spring kit to see if I can that popping worked out. Fingers crossed. Will be picking up the 750 carb tonight and start disection and cleansing of it. Will also try to get my wideband installed.

springs in hand along with msd bushing and spring kit. Will change the carb springs at 2 o'clock baybe get a quick test drive in then do the advance springs

The Power piston springs I used most often John with E carbs was the Pink or Purple springs.
Sometimes the short natural color springs also with Hot cams.
Start with a 7-8 inch calibration setpoint power puston spring pair.
A vacuum guage connected to manifold vacuum source best.
See the actual vacuum at idle & part throttle driving condition.
Then wideband fir correct jets.

Will check vacuum today and install proper spring. I picked up my snap on vacuum guage and grabbed my ole 750 Edy from the parents garage. I started a complete tear down on it last night. It will look like a better than new carb when I am done with her. I had installed the light spring before I read your post Brian and the popping still is there. Still haven't changed the springs in the distributor.

Ok that a side will see vacuum during lunch today 12:30 EST and add springs accordingly. Timing curve- Does this sound right?
Set 11-12 Degrees BTDC initial (no vacuum of course)
Change Blue bushing that gives 21 degrees timing for Silver which adds 25 degrees
Run the two light silver springs to be full in by 2400 rpm

Bushing options
Red-28
Silver-25
Green-23
Blue-21
Purple-19

Black-18

vacuum at idle 800rpm I had 8" of vacuum
Vacuum at idle 1000rpm was 14" of vacuum
Left torx head on desk with 750cfm so couldn't purt heavier springs in but from those vacuum readings what are you thinking?

I got the advance springs in during lunch think that cleared up the popping out the exhaust will test drive during 2pm break. I also played with the idle mixure screws while I had the vacuum gauge and my buddy from work with me to watch the rpms. Will keep you all informed.

JUST A REMINDER FOR ANYONE WITH CASH TO THROW AT THE ISSUE, THERES SEVERAL LAP TOP PROGRAMMABLE IGNITION OPTIONS
programmable ignition advance curves
(yes it would be so easy if we all had deep pockets and nearly bottomless checking account balances wouldn,t it?)

http://www.msdignition.com/exe/setup_prodata319.exe

youll need a #6530 control box http://www.summitracing.com/parts/msd-6530 $366

a #8570 distributor http://www.summitracing.com/parts/msd-8570 $266

A # 8253 coil http://www.summitracing.com/parts/msd-8253 $186



http://www.speedwaymotors.com/Tech/the- ... boxes.html

http://www.msdignition.com/Products/Ign ... 6AL-2.aspx

http://www.ignitioninfo.com/

http://www.msdignition.com/WorkArea/Dow ... 5032386168

http://www.summitracing.com/parts/msd-6530

http://static.summitracing.com/global/i ... m28932.pdf

MSD is bringing their pro stock ignition technology to the street with their new Programmable 6AL-2! Since every NHRA Pro Stock car uses a Programmable Digital-7 Ignition Control, it was only a matter of time until MSD brought that technology to the street – and the time is now!


The new ignition, Part Number 6530, is based on the same output as the 6AL-2, but rather than rotary dials for rpm adjustments it sports a serial port that connects to a PC. Once you load MSD’s Windows based software on your PC, you’re ready to start mapping and programming. To start, you can get rid of the weights and springs that control the mechanical advance of your distributor. Go ahead and lock it out because you can now create a timing curve that allows you to manipulate the timing down to tenth of a degree increments every 100 rpm. The advantage is precise timing control, with the ability to ramp the timing in or retard it at exactly the rpm that you want it to move. Want more timing out for a start retard? Simply click the mouse and move a couple dots in position. Like a high speed retard? Clickity-click!


Another great feature is for the forced induction fans. The ignition features a timing curve based on boost so you can map out a timing curve based on boost pressure. The feature that most street guys will dig is the ability to pull timing out during the holeshot – and ramp it back in. Since many cars have more power than traction capabilities, being able to soften the power at the holeshot can help reduce the tire shredding off the line.


There are also three different rpm limits that can be set in 100-rpm increments; one for the burnout, one for the holeshot and of course a top end limit for overrev protection. If you have a nitrous shot you like to blast off now and then, the ignition has an activation wire that you tie into the nitrous wiring. When the nitrous is activate, the timing can be retarded instantly!

I know that would be nice grumpy my pantera efi ecu does that and has coil drivers as well. The springs helped and the idle is smoothed out better. It still popped through the exaust when not under load. I disconnected the vacuum advance and the popping is gone. I will try to get the bushing changed in the distributor I was gonna do it during lunch but I did not have a metric wrench set with me and the adjustable was to big.

Strictly Attitude said:

vacuum at idle 800rpm I had 8" of vacuum
Vacuum at idle 1000rpm was 14" of vacuum
Left torx head on desk with 750cfm so couldn't purt heavier springs in but from those vacuum readings what are you thinking?

I got the advance springs in during lunch think that cleared up the popping out the exhaust will test drive during 2pm break. I also played with the idle mixure screws while I had the vacuum gauge and my buddy from work with me to watch the rpms. Will keep you all informed.

Click to expand...

I figured you had around 7-8 inches at idle John with the Isky Cam in there.
Install a 7 spring.
Test drive.
Write down the primary and secondary jets on a sheet of paper.
Jet sizing is for gross fuel tuning.
Metering rods changed for fine tuning AFR.

AFR Will need to be on the Rich side John.
Isky cam has decent numerical valve overlap present.
Give the engine what it wants.
Not what You want.

I am with ya Brian and appreciate the advise. Tomorrow the new spring goes in no calibration kit yet doing a complete douch on the 750 it is gross but getting there will snap some shots tonight that flat cam reaked havoc on my carbs by backfiring through them and the bowls are full of crap also twenty year old carb off my trans am when the holley drag race carb decided it was to cold out to play the winter friendly one went on.

Pink springs installed during 9am break the one thing I do love about an Edy is how fast adjustments can be made on the car need to call around and see if I can locate a gasket or gasket set for the 750 edy the top gasket shit the bed during clean up. I ran the part through the ultrasonic at work now doing final cleaning on them. The Carb body still needs more clean up but the top plate is done also. Hopefully can find a gasket and get the wideband and 750 installed this weekend if I get the time. The carb is installed almost a guarentee but the wideband not so much. Only cause I need to weld the bung and welders at my parents.

Ran very good got rid of mid-range surging I was experiencing another big thanks Brian. Now got all the parts final cleaned from the 750 just have to get at the carb body tonight. And get the wide-band in tomorrow.

Strictly Attitude said:

Ran very good got rid of mid-range surging I was experiencing another big thanks Brian. Now got all the parts final cleaned from the 750 just have to get at the carb body tonight. And get the wide-band in tomorrow.

Click to expand...

Awesome John.
You will have fun now fine tuning the Eddyy Carb.
I have lots of experience using them prior.
Nice when dialed in.

will also get that bushing installed and the timing squared away gonna need new rear tires and wheels before I do the rear end or gonna have major traction issues. I can smoke it well into second from a rolling start right now. :lol: