My engine setup for my '79 is in my signature. I've been playing with the tuning on this carb. The stock setup is a .098 pri jet w/ a 75x47 rod, .095 sec jet, yellow (4 in HG) spring which is ref position 1. In the past I had calibrated it way too rich and fouled the plugs. I had .098 pri jet w/ a 70x37 rod and a .101 sec jet. I had also replaced the pump nozzles with the .043, which I believe is the largest available. The stumble was almost eliminated. But I was fouling plugs and I believe the rich mixture was masking my problem. Accelerator pump rod is in the top hole. I replaced the accelerator pump. I leaned it back out to ref position 2, which is a .095 jet w/ a 70x37 rod in the primary and a .098 sec jet. This set up is "stock" cruise mode (I do not have any lean surge issues) and 4% rich power mode and 4% rich in the secondary. I've put in the silver (7 in Hg) spring which seamed to help a little. The car will smokeum from idle and does not stumble. It runs very well in that mode. When cruising at speed, and I punch it, it stumbles badly. Once it recovers it runs strong. If I "ease" the throttle down at highway speed, it doesn't stumble. I do beleive I just need a bigger pump shot. But as far as I know, I have the biggest nozzles. Has anyone drilled out the .043 to a larger size?

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2000 Corvette hardtop black, 6 speed, Halltech Tric cold air intake w/nylon MAF ends, Corsa Touring cat back exhaust w/pro tips, Taylor wires, 1/4 mile: 12.918 @ 111.29 mph on stock EMT's 330 rwhp, 342 rwt on MTI's dyno, 3075 lbs

79 Camaro 355 CID, Edelbrock intake, Edelbrock 600 cfm carb, Edelbrock performer 64 cc alum cyl heads, comp cams extreme energy 262 cam, erson roller rockers, hooker headers, Mallory Comp 9000, 3.42 posi, 700R4 rebuilt w/ B&M kit, 2400 stall converter w/ TCI lockup kit, energy suspension f.e. rebuild, 1-1/4 front sway bar, 5/8 rear bar

67 Camaro, 327 w/ a 'glide , waiting on "funding"

[This message has been edited by need-for-speed (edited April 05, 2005).]

Raise the float level 1/16" higher than the manual says, and bend the accelerator pump rod (CAREFULLY) so that exactly 13/32" of the pump protrudes above the carb body. Fixes 99% of the Eddy carbs that have the exact problem you describe.

Thanks Marv! That makes sense. I was curious why there was no stumble off idle, but there is at highway speeds. But the float level would not be an issue at idle, whereas it could be at the higher rpm. I'll cross my fingers and try that out this weekend.

As I stated above, the stumble is NOT off idle. The larger pump nozzles completely cured that. It will smokum at will from a dead stop. The stumble is when punching it at highway speeds.

Do like Marv said. The float settings are printed wrong in the manual and set wrong, in I think 01 or 02 edelbrock changed that, and all carbs newer than that are said to be set at the new level (mine was way off), but atleast the new manual has the right setting listed

I don't see how you got that carb to work right in the 1st place. Thats eddy "econo caled" carb, tuned for mileage rather than performance.

Every car is diif, but in my case i'm running the 1405 carb, pump nozzles was fine, jet needed the float level set, metering rod change, step up spring change, sec. jet change, and pump arm moved up

Stock for mine is... Stock .100" main jets .095" sec jets .070 x .047 rods, orange 5" springs

I ended up with.....
.100" main jets .098" sec jets, .068 x .042 rods, pink 7" springs

BTW... silver springs are 8" HG not 7"

By "econo carb" do you mean the 600 CFM? I do have the 1408 which was the EGR version and had a mild setup but I didn't "reveal" that it was a 1408. Maybe you recognized the calibration specs? I'm just curious.

Glad to hear another confirmation of the "float" issue. Thanks for the history on the float issue. I'm looking forward to getting on that this weekend. The car really runs well and makes a ton of torque w/ that carb other than the stumble. I will try dropping back to the pink springs if Marv's fix works. Hell, I might even be able to go back to smaller nozzles. But I'll try 1 change at a time to keep it simple. Thanks for the input and the good info.

I recognized the calibration specs. I been messing around with these carbs for quite awhile.

.098/.095 jets, .075/.047 rods, yellow springs is the specs for the # 1406 600 cfm elec. choke carb. It has the .031" nozzle.

The 1406 is known as the econo edelbrock because it's calibration is soo lean out of the box. Works best on stock "smogger" engines in the smaller cid range, or in cars you want to get better fuel mileage out of.

The 1405 has the "performance" calibration for a 600 cfm carb. (in most cases too rich out of box for stock-ish engines, and too lean for performance engines)

Stock with .100/.095 jets, .070/.047 rods, orange springs, .028" nozzel

From edelbrock....
the 1405.... "Designed and calibrated for optimum street performance in small-block and some big-block engines"

the 1406.... "Designed and calibrated for good street performance and fuel economy in small-block and small displacement big-block engines"

Good job on recognizing the specs. I suspected you did. Yes, before I arrived at my existing calibration, I changed my setup to be similar to the 1405. I had come across the same description that you posted. I had gone even richer in search of a cure for the lean stumble. I may go back to that setting (or even your current calibration) after the fix. What is the setup on your motor? displacement, heads, cam, intake, etc?

Thanks man.. Yeah after fooling with these thing for 5 or 6 years, you pretty much know all the specs on them lol.

My engine is kinda mild IMO.

355, 10.18:1, GM 462 heads, ported, manley 1.94"/1.5" valves, crane powermax 272-2 cam. (272/284*, 216/228*@.050", .454"/.480" lift, 112 lsa)
1.6 roller tip rockers (brings .050" duration to about 218/230, and lift to .484"/.512")
edelbrock performer intake (port matched, center divder wall milled down 2" x 1")
1" open carb spacer
K&N 10" x 3.75" air filter, set up in a sealed cold air system.

To get my calibration I ran at the track, adjusting, changing parts, etc till I got the highest MPH trap speed.

Once I got that. I played with low speed tuning. I had the same sec jets and rods as I listed, but had .098 prim. jets too, which was alittle rich around town, so next traip to the track, I swapped the stock .095's back in, after I made 2 base line runs (cause you know times changes bases on air temp, track, etc), then made 2 passes with the 095's in the prim.... No change to my MPH

So thats what I left in. Runs about right at lower speeds, not rich at all. Runs great WOT , and everywhere in between

Thanks for the info nightrider. My cam is 218/224 @.050 and .462/.469 w/ 110 LSA so it's not too far from yours except the 1.6 rockers and my CR is 9.5:1.

So, I don't understand on your final calibration. Is it 100" main jets .098" sec jets, .068 x .042 rods, pink 7" springs? In your latest post, you mention .098 jets and then .095? Just curious. I think I'd like to try your calibration as long as you're not at high altitude. What altitude are you at? I'm 100 miles east of Houston so we have high humidity, 30 feet above sea level. Thanks.

Hey man... Sorry about how I worded that info on my calibration.. It was late, no sleep and my mind wasnt thinking. Man I really screwed that post up lol

.098's main jets was too LEAN for street, but ran good at the track. Went back to stock size .100 main jets and it was just right for street, and no change to me track MPH.

Sec. jets was too lean at the stock 095's so I had to go to 098's in the sec.

Rods are 068 x .042 rods, pink 7" springs

I'm in GA about 55 miles west of Atlanta, and race at Atlanta dragway (about 100 miles north/north east of my house). I think the altitude is 100 ft above sealevel. GA. always has pretty high humidity.

Hey that's great information!! I understand about the late hours .... LOL Thanks for the clarification. You live in a beautiful area and yes, your altitude and humidity are very similar to mine (at least in the summer). My nephew lives in Sugar Hill. Thanks for the info. I think I'll give your setup a try after I do the float and pump lever change and see how it compares to mine.

Mike


[This message has been edited by need-for-speed (edited April 08, 2005).]