Re: question for guys running 2-4 edelbrocks
[Re: second 70]
#2681250
07/25/19 01:01 PM
07/25/19 01:01 PM
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Joined: Aug 2003
Posts: 43,292 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,292
Bend,OR USA
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Me thinks you may be wrong on the results due to the area differences between a large hole with a larger step metering rod versus the smaller jet with a smaller metering rod step Try it both ways and let us know Which type Eddy . carb are you wanting to use, the street carbs. or race carbs. part #s?
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: question for guys running 2-4 edelbrocks
[Re: second 70]
#2681336
07/25/19 04:48 PM
07/25/19 04:48 PM
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Joined: Jan 2003
Posts: 31,074 Oregon
AndyF
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I Win
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Oregon
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I was wondering if anyone ever noticed any difference from how they jetted the primary jets? You can either have a larger jet with a large metering rod or a smaller jet with a smaller rod. You could dial in the AFR either way I was just curious if ones better than the other for the carb signal or power.
Mike If doesn't matter as long as you can tune it. If it was me I'd stick with what Edelbrock recommends in their tuning guide since then you can buy a tuning kit and have everything you need to go richer or leaner.
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Re: question for guys running 2-4 edelbrocks
[Re: dvw]
#2681357
07/25/19 06:13 PM
07/25/19 06:13 PM
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Joined: Dec 2012
Posts: 1,824 Wind Gap,Pa.
Sammy
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Wind Gap,Pa.
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Area is area. That being said NO WAY square jet. Secondarys are rich enough at the factory setting or very close to it. Doug You are wrong. Unless you own a data logger with 8 O2 Sensors, or go on a dyno with 8 sensors, you will never know. If you owned a racepak with 8 O2 Sensors you would see where to jet it. Primaries run #1,2,5,6 cylinders Secondaries run #3,4,7,8 My little small block with a sheetmetal intake was pretty close to square jetting. If your intake manifold is semi even in distribution, you will see slight variances in jetting from front to back. Maybe the secondaries could possibly be 3 jet sizes leaner.
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Re: question for guys running 2-4 edelbrocks
[Re: second 70]
#2681377
07/25/19 07:09 PM
07/25/19 07:09 PM
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Joined: Jan 2003
Posts: 31,074 Oregon
AndyF
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I Win
Joined: Jan 2003
Posts: 31,074
Oregon
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Andy since I'm running 2-1405's at 1 to 1 on a stage V manifold the chart doesn't go lean enough for light street use. It gets close and I use the chart for the 1406 which is also a 600 carb but not jetted near as rich. I just increase or decrease the part of rod that need it. Trial and error. Okay so your first mistake was to use the wrong carbs. Edelbrock sells carbs that are calibrated for dual carb use but evidently you didn't buy those. Since you have the wrong carbs you need to rejet them the way Edelbrock wants the dual carbs jetted. Download the instructions for the dual carb calibration and then buy the correct jets and metering rods for dual carb calibration and you should be on your way.
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Re: question for guys running 2-4 edelbrocks
[Re: AndyF]
#2681483
07/26/19 07:53 AM
07/26/19 07:53 AM
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Joined: Jun 2008
Posts: 3,916 usa
lewtot184
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usa
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Andy since I'm running 2-1405's at 1 to 1 on a stage V manifold the chart doesn't go lean enough for light street use. It gets close and I use the chart for the 1406 which is also a 600 carb but not jetted near as rich. I just increase or decrease the part of rod that need it. Trial and error. Okay so your first mistake was to use the wrong carbs. Edelbrock sells carbs that are calibrated for dual carb use but evidently you didn't buy those. Since you have the wrong carbs you need to rejet them the way Edelbrock wants the dual carbs jetted. Download the instructions for the dual carb calibration and then buy the correct jets and metering rods for dual carb calibration and you should be on your way. I believe the edlbrock "dual quad" carbs are manifold/ engine specific, or that's how I've treated it when looking at their carbs. the only dual carb issue I've found is not using a matched pair. I bought a 1406 and a 1405 for my set-up thinking simple metering rod and jet changes were all I needed. I found out the clusters/idle jets along with metering rods/jets were all different. another educational opportunity for me, but in the end a very nice street package.
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Re: question for guys running 2-4 edelbrocks
[Re: AndyF]
#2681556
07/26/19 11:15 AM
07/26/19 11:15 AM
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Joined: Feb 2014
Posts: 1,713 central il.
second 70
OP
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OP
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central il.
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Andy since I'm running 2-1405's at 1 to 1 on a stage V manifold the chart doesn't go lean enough for light street use. It gets close and I use the chart for the 1406 which is also a 600 carb but not jetted near as rich. I just increase or decrease the part of rod that need it. Trial and error. Okay so your first mistake was to use the wrong carbs. Edelbrock sells carbs that are calibrated for dual carb use but evidently you didn't buy those. Since you have the wrong carbs you need to rejet them the way Edelbrock wants the dual carbs jetted. Download the instructions for the dual carb calibration and then buy the correct jets and metering rods for dual carb calibration and you should be on your way. Here’s the recommended carb cart from Edelbrock mild/performance big block 2-1405 no calibration kit available.
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Re: question for guys running 2-4 edelbrocks
[Re: second 70]
#2681584
07/26/19 12:40 PM
07/26/19 12:40 PM
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Joined: Jun 2008
Posts: 3,916 usa
lewtot184
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Joined: Jun 2008
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usa
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Andy since I'm running 2-1405's at 1 to 1 on a stage V manifold the chart doesn't go lean enough for light street use. It gets close and I use the chart for the 1406 which is also a 600 carb but not jetted near as rich. I just increase or decrease the part of rod that need it. Trial and error. Okay so your first mistake was to use the wrong carbs. Edelbrock sells carbs that are calibrated for dual carb use but evidently you didn't buy those. Since you have the wrong carbs you need to rejet them the way Edelbrock wants the dual carbs jetted. Download the instructions for the dual carb calibration and then buy the correct jets and metering rods for dual carb calibration and you should be on your way. Here’s the recommended carb cart from Edelbrock mild/performance big block 2-1405 no calibration kit available. I don't think i'd get overly lost in that chart. it's just too general. I use a ch28 with two 600's. primary jets on both carbs are .101", metering rods 71x47, orange step-up springs, .098" secondary jets (near identical to factory 1405 jetting). I have edelbrock RPM heads, modest solid lifter cam (238@.050"/.510" lift), full TTI exhaust, automatic with 3.23 gears, and factory 10 3/4" converter. I wish i'd tried this set-up years ago. very trouble free, torquey, low maintenance, drive anywhere.
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Re: question for guys running 2-4 edelbrocks
[Re: lewtot184]
#2681595
07/26/19 01:50 PM
07/26/19 01:50 PM
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Joined: Feb 2014
Posts: 1,713 central il.
second 70
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I don't think i'd get overly lost in that chart. it's just too general. I use a ch28 with two 600's. primary jets on both carbs are .101", metering rods 71x47, orange step-up springs, .098" secondary jets (near identical to factory 1405 jetting). I have edelbrock RPM heads, modest solid lifter cam (238@.050"/.510" lift), full TTI exhaust, automatic with 3.23 gears, and factory 10 3/4" converter. I wish i'd tried this set-up years ago. very trouble free, torquey, low maintenance, drive anywhere. [/quote]
Thanks for your results.
A couple of things first you are right about the 1406 carb. The edelbrock tech told me that it was not just a 1405 with a automatic choke and leaner jetting, that it was an economy carb and totally different and not to be used on dual quads because it would be lean even if jetted the same as the 1405 and not a match. If you wanted an automatic choke you would add it to the 1405. If you look at the chart the 1403/1404 500's are compatible for dual usage because the choke is the only difference.
Second The factory jetting would be close for me if I was running a progressive linkage but the Stage V requires it to be 1 to 1 so it needs to be leaner because of running off both carbs and not just one down low.
Also just for the heck of it the pair of 500 they sell are setup for a small block Chevy with progressive linkage. They take the factory setting which was .086 main .095 secondary jets & .065 x.052 metering rod and change it to .086 main .077 secondary jet and rod change to .065 x .057 So that comes out to 8% less cruise and 24% less secondary jet.
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Re: question for guys running 2-4 edelbrocks
[Re: second 70]
#2681607
07/26/19 02:40 PM
07/26/19 02:40 PM
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Joined: Jun 2008
Posts: 3,916 usa
lewtot184
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master
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usa
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I don't think i'd get overly lost in that chart. it's just too general. I use a ch28 with two 600's. primary jets on both carbs are .101", metering rods 71x47, orange step-up springs, .098" secondary jets (near identical to factory 1405 jetting). I have edelbrock RPM heads, modest solid lifter cam (238@.050"/.510" lift), full TTI exhaust, automatic with 3.23 gears, and factory 10 3/4" converter. I wish i'd tried this set-up years ago. very trouble free, torquey, low maintenance, drive anywhere.
Thanks for your results. A couple of things first you are right about the 1406 carb. The edelbrock tech told me that it was not just a 1405 with a automatic choke and leaner jetting, that it was an economy carb and totally different and not to be used on dual quads because it would be lean even if jetted the same as the 1405 and not a match. If you wanted an automatic choke you would add it to the 1405. If you look at the chart the 1403/1404 500's are compatible for dual usage because the choke is the only difference. Second The factory jetting would be close for me if I was running a progressive linkage but the Stage V requires it to be 1 to 1 so it needs to be leaner because of running off both carbs and not just one down low. Also just for the heck of it the pair of 500 they sell are setup for a small block Chevy with progressive linkage. They take the factory setting which was .086 main .095 secondary jets & .065 x.052 metering rod and change it to .086 main .077 secondary jet and rod change to .065 x .057 So that comes out to 8% less cruise and 24% less secondary jet. [/quote]if this is stage V hemi don't put those 500's on it. I wouldn't put a 500 on a lawnmower. street hemi carbs used the same venturii and throttle bore size as the edelbrock 600's. if it's a big inch engine i'd go directly to the 750's. the 750's have the same venturii and throttle bore size as the '67 ss/b hemi cheater carbs, or '64 s/s max wedge.
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Re: question for guys running 2-4 edelbrocks
[Re: second 70]
#2684630
08/05/19 11:11 AM
08/05/19 11:11 AM
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Joined: Oct 2004
Posts: 2,839 Connecticut
FurryStump
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Connecticut
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If you truly square jet these carbs they are not square jetted. The rod is in the primary jet and limits flow. My combo I’m sure has distribution issues and I’m running the 800 avs, but that being said it will not run anywhere near square. I have also seen it on a hemi really liked fat primary and leaner secondary. So it’s going to take trial and error, but don’t be afraid to move off of square jetting. Track cars. Honestly thinking about it I have never done the surface area math. So taking into consideration the rod in the primary the actual flow might be square, but the jet size isn’t
Last edited by FurryStump; 08/05/19 11:15 AM.
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