Understanding edelbrock tuning

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CSFJ

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The 1405 is "calibrated for performance", which means it is even richer than most Edelbrocks. So your carb tune is all wrong for that engine. And it's showing. I get 10 mpg in town with a K10 with a TH350 and 31" tires on 3.73:1 axles.

Edelbrock 1405 is .100 primary, .095 secondary, 70/47 rods, and 5" step-up springs. What you need for that engine is more like .092 primary, .095 secondary, 65/57 rods, and 8" step-up springs. These are easy changes. Here's the part numbers you need: primaries: jets .092 (#1425), rods .065 x .057 (#1461); secondaries: stock; step-up springs: 8# (comes with #1464). You will also need to replace the airhorn gasket (qty 5 is #1499) when you change the primary jets. Adjust the float bowls while you are in there, as they will be wrong, probably to the high side.

Then, you need to adjust your timing. Odds are you have the vacuum advance in the wrong vacuum port, are running the wrong vacuum advance can, and have the timing way retarded from its optimum setting. This will all cost you in fuel consumption.

Read this on timing: http://www.gmsquarebody.com/forum/showthread.php?t=14508

And put the AR23/VC1853 vacuum advance canister on the distributor.
http://www.napaonline.com/Catalog/C...cuum-Advance-Control/_/R-ECHVC1853_0168354142

Rich
 

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Is there a difference between the edelbrock, carter afb/avs, and the quadrapuke??? I thought they were all the same....
 

Honky Kong jr

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Is there a difference between the edelbrock, carter afb/avs, and the quadrapuke??? I thought they were all the same....
The slobberjet has more ******** inside. Lol I done like any of them.
 

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My first question is you didn't use that spring like in your pic did you? on the metering rod, because it goes up under the piston.

Lol no, I just had it like that to keep it all together. Carb runs much nicer now, idles like a dream again too
 

Obwonkonobe

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The 1405 is "calibrated for performance", which means it is even richer than most Edelbrocks. So your carb tune is all wrong for that engine. And it's showing. I get 10 mpg in town with a K10 with a TH350 and 31" tires on 3.73:1 axles.

Edelbrock 1405 is .100 primary, .095 secondary, 70/47 rods, and 5" step-up springs. What you need for that engine is more like .092 primary, .095 secondary, 65/57 rods, and 8" step-up springs. These are easy changes. Here's the part numbers you need: primaries: jets .092 (#1425), rods .065 x .057 (#1461); secondaries: stock; step-up springs: 8# (comes with #1464). You will also need to replace the airhorn gasket (qty 5 is #1499) when you change the primary jets. Adjust the float bowls while you are in there, as they will be wrong, probably to the high side.

Then, you need to adjust your timing. Odds are you have the vacuum advance in the wrong vacuum port, are running the wrong vacuum advance can, and have the timing way retarded from its optimum setting. This will all cost you in fuel consumption.

Read this on timing: http://www.gmsquarebody.com/forum/showthread.php?t=14508

And put the AR23/VC1853 vacuum advance canister on the distributor.
http://www.napaonline.com/Catalog/C...cuum-Advance-Control/_/R-ECHVC1853_0168354142

Rich

Great advice and starting point, much appreciated
 

74 Shortbed

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Il go back and look for numbers on the jets, those tiny round things right?
The numbers on the jets are almost impossible to make out sometimes, numbers are actual hole sizes in thousands use drill bits to verify actual size, use calipers to measure the steps on the rods, beats trying to read the numbers..
 

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The numbers on the jets are almost impossible to make out sometimes, numbers are actual hole sizes in thousands use drill bits to verify actual size, use calipers to measure the steps on the rods, beats trying to read the numbers..
Or better yet send it to me and I will tune it like it should be.
 

74 Shortbed

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Or better yet send it to me and I will tune it like it should be.
LOL, they are a POS but they are easy to tune, and they're ok for just going down the road with decent mileage, key to making them trouble free is keeping them clean, best filter is almost not good enough..
 

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LOL, they are a POS but they are easy to tune, and they're ok for just going down the road with decent mileage, key to making them trouble free is keeping them clean, best filter is almost not good enough..
Which is why I laugh when I see them on blowers and tunnel rams. It’s like smearing **** on your truck and calling it paint.
 

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Which is why I laugh when I see them on blowers and tunnel rams. It’s like smearing **** on your truck and calling it paint.
Putting them on a blower is a total joke for performance, but then again some of those clowns put a blower on just for show and they just drive them around so they work, and they also subject themselves to extreme embarrassment when challenged, lol, bout the same with a tunnelram... My take on that **** is, if it looks fast it needs to be faster than what it looks, lol..
 

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Putting them on a blower is a total joke for performance, but then again some of those clowns put a blower on just for show and they just drive them around so they work, and they also subject themselves to extreme embarrassment when challenged, lol, bout the same with a tunnelram... My take on that **** is, if it looks fast it needs to be faster than what it looks, lol..
Got that right.
 

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Got that right.
One of my best friends went through that with his boat, sounded and looked like 150mph but ran 75 on a good day, lol, kept telling him over and over and over, one of these days and sure as ****, we were kicking back at the river one day and this guy comes cruising by and eyeballing his boat, he went back and forth a few times and whacked the throttle, my friend took the bait I told him not to do it but wouldn't listen, so he went out and got his ass handed to him, lol, I talked to the guy after that and all he had was a well tuned 440 with a 750 Holley on a dual plane intake super sleeper, I caught it the first time he whacked the throttle, lol, my friend had a 468 with an 871 that hardly turned, I thought he was going to jump out of his boat and go the the bottom and stay there till everyone left, lmao...
 

Honky Kong jr

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One of my best friends went through that with his boat, sounded and looked like 150mph but ran 75 on a good day, lol, kept telling him over and over and over, one of these days and sure as ****, we were kicking back at the river one day and this guy comes cruising by and eyeballing his boat, he went back and forth a few times and whacked the throttle, my friend took the bait I told him not to do it but wouldn't listen, so he went out and got his ass handed to him, lol, I talked to the guy after that and all he had was a well tuned 440 with a 750 Holley on a dual plane intake super sleeper, I caught it the first time he whacked the throttle, lol, my friend had a 468 with an 871 that hardly turned, I thought he was going to jump out of his boat and go the the bottom and stay there till everyone left, lmao...
All show and no go will get you no where.
 

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