Step up spring clarification? AVS2

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DesertRat

Leading edge boomer
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I am getting ready to install the new rods and springs in my AVS2. I have the complete eddy spring set and my research shows to pick the spring that is rated at 1/2 of your vacuum at hot idle in drive for an automatic. Does this sound correct? Thanks for the help in advance!
 
It should tell in the instructions or may be download from Edelbrock's website. I just printed off the tune directions for my 1406's. I have glanced through the instructions but haven't studied. I did see a chart where it carb adjustments are in the center and it tells you what direction to go if you need rich or lean. It seems to be a bit confusing if you are just adjusting by the seat of the pants.
 
It should tell in the instructions or may be download from Edelbrock's website. I just printed off the tune directions for my 1406's. I have glanced through the instructions but haven't studied. I did see a chart where it carb adjustments are in the center and it tells you what direction to go if you need rich or lean. It seems to be a bit confusing if you are just adjusting by the seat of the pants.
Thanks Mike: I talked to the Eddy tech line and the AVS2 tunes completely differently from the 1406. The tech I talked to recommended the rods I got and I bought the spring kit which has them all for $10 so its a no loose deal. They are working on the tuning charts for the AVS2 but they are not complete. I will just read my hot vacuum in park and go with the spring calling for that "of HG to start.
 
Bookmarking this one :) I've put on three AVS2 Carbs this year (2 on friends cars) and so far they have been great right out of the box. I put the 650 on my car but the weather has turned to **** so not much playing around with it. I'll put the A/F gauge on it in the spring. Was yours lean or rich and at what circuit? Also what is your altitude?
 
Bookmarking this one :) I've put on three AVS2 Carbs this year (2 on friends cars) and so far they have been great right out of the box. I put the 650 on my car but the weather has turned to **** so not much playing around with it. I'll put the A/F gauge on it in the spring. Was yours lean or rich and at what circuit? Also what is your altitude?
I started with a wideband on mine so it was easy to see. It is running fine at hot idle but rich at cruise, about 12.5+-. I want it to cruise about 13.5+- so it is a small adjustment. The tech wanted me to leave it alone but he isn't buying my gas so he reluctantly recommend the rod change that I bought and the spring kit was a no brainer. I will keep the thread posted.
Edit: The tech said to read the plugs, it was more important and my plugs read perfectly the way the carb is now.
 
I knew something was different in them other than the boosters but being brand new I wasn't going to dissect them. Oh and your are correct they did not come with the chart the other carbs come with. My thinking is the air bleed holes or routing is changed so the jets and rods are going to be different.
 
Cool. A little fat might not be to bad this time of year. But yea, a rod and spring change is nothing to do. Keep us updated and thanks :)
 
I started with a wideband on mine so it was easy to see. It is running fine at hot idle but rich at cruise, about 12.5+-. I want it to cruise about 13.5+- so it is a small adjustment. The tech wanted me to leave it alone but he isn't buying my gas so he reluctantly recommend the rod change that I bought and the spring kit was a no brainer. I will keep the thread posted.
Edit: The tech said to read the plugs, it was more important and my plugs read perfectly the way the carb is now.
I think a wideband is the way to go. A little fatter rod on the little end. Doesn't sound like it's that far off. As long as it doesn't ping. Have you noticed a difference in how it runs or sounds?
 
I think a wideband is the way to go. A little fatter rod on the little end. Doesn't sound like it's that far off. As long as it doesn't ping. Have you noticed a difference in how it runs or sounds?
I just got my valvetrain sorted and checked my vacuum. I have 12" hot in park and 10" in drive. Will probably change the rods first without a spring change and go from there.
 
I am getting ready to install the new rods and springs in my AVS2. I have the complete eddy spring set and my research shows to pick the spring that is rated at 1/2 of your vacuum at hot idle in drive for an automatic. Does this sound correct? Thanks for the help in advance!
That's what Edelbrock told me. But it did not work. First of all, good luck figuring out which spring is which in that kit. The color-coding really sucks, and doesn't really jive with the chart they supply. I'm just doing trial & error now. Damn thing still has a big "bog" when you stomp on it.
 
I just got my valvetrain sorted and checked my vacuum. I have 12" hot in park and 10" in drive. Will probably change the rods first without a spring change and go from there.
I changed the rods and springs. I should have only changed the rods, putting stock springs back in in the morning. I redid my valve cover gaskets as I had a weep and tested the car. It idles at 14.6+- and cruises at 14,2/3 jumping around a bit. It is running 5 degrees hotter than is was so it's definitely leaner. I will test and report after putting original springs but leaving the fatter rod to see if that helps. With this weather I may just put the original stuff back in, winter likes a little more fuel. More later-------------------
 
So the verdict is in. The stock rods that were in my AVS2 from the vendor were 70 X 52 and the change recommended by Edelbrock was to change to 73 X 52 which I did. I left the springs that came with the carburetor and my wideband shows 14.6 at idle and 13.5-14 at light cruise which was my target. I am not changing anything else on the car now. I think the as-shipped rod/spring combo would be fine for more CI but my little 273 didn't need that much fuel. I'm moving on to my 40 ford pickup/Y-block build which I can't post about here.
 
Update on my AVS2 tuning marathon. I downloaded an AVS2 tuning chart from the Edelbrock website. Studying it I decided to lean out with one size smaller jets and the rods recommended to go with the jets. Went from 095 jets to 092 and the new rods are 67 X 45 or something like that. The Edelbrock tech pages say to use the strongest spring you can so I put the pink springs in it this morning. I think I could go one size stronger but here is what happened. My lean/off/idle bog is gone. The car idles smoother and is better through the entire range so it is very close. My wideband did not lean out as expected. I haven't driven it enough to know the true cruise AFR but it is still in the 13+ at cruise and the idle rpm is 600 hot neutral and 500 hot in gear. I like where it is going but I will put in one size stronger springs and see where it goes.
 
I am running the leanest setting on the AVS2 chart and still running 12.5-14.5 afr.
These carbs are not as easy to tune as they say. I have trouble noticing changes in springs and air door settings.
 
I am running the leanest setting on the AVS2 chart and still running 12.5-14.5 afr.
These carbs are not as easy to tune as they say. I have trouble noticing changes in springs and air door settings.
Do you guys like the way they run? Is there a noticeable difference in them over your old Edelbrocks?
 
Throttle response is better than my Holley but power is down. I havent used AFBs all that much over the years.
 
Do you guys like the way they run? Is there a noticeable difference in them over your old Edelbrocks?
I changed from a Holley I fought for 2 years. There is no doubt in my mind that this AVS2 is the superior carburetor. After yesterdays changes my car ran the best it has since I put it together. I agree with the previous post though, Edelbrock beat the tuning knowledge to market with the product. I think I need to change springs to one set softer but wont the to it until later this week.
I am good all the way through the range but I have not changed the secondary air door settings. I have good power and when the secondaries come in, hang on!
 
@DesertRat what cam are you running ?
Did you say you have 14ish vacuum at idle ?
I dont see how the strongest spring could work with 14”s
 
@DesertRat what cam are you running ?
Did you say you have 14ish vacuum at idle ?
I dont see how the strongest spring could work with 14”s
I am running a Lunati hydraulic version of the stock 273 Commando cam with a little more lift and duration, not much though. The pink spring is not the strongest but should be the one for 14" of vacuum at idle. I will do down one spring this week but I want to get some road miles on this setting to compare.
 
I have reached satisfaction with my Edelbrock 500 CFM AVS2 on my 273 Commando (type) build. The biggest help achieving this for me was figuring out how everything worked together. (this is for the guys new to tuning these carburetors. You experts forgive me as I know you all already know this. Full disclosure I have a working wideband on my car. After looking at charts I made the decision to buy rods and jets. I already owned one set of rods and the entire spring set. The light came on when I realized the springs had to let the rod down into the "zone" to meter properly. Then it was a matter of watching the vacuum gauge and the wide band. The setup I found worked best for me is .092 jets, the orange spring 5 HG on the box and 70-52 rods down from 73-52. I'm running 15 degrees initial and I recurved the distributor allow another 15 degrees of advance with no vacuum advance. Tried it both ways and this works for me. It will actually go past 35 degrees advanced with the timing light on it and no-load acceleration. On the street now the car performs like I envisioned when I built it. Starts on the first crank hot or cold, and importantly is Smooooooth up and down the scale with the wideband in the sweet spot. Can't say much more other than I am really glad I have this carburetor on my car.
 
Avs2?

Is the thunder 800 AVS in this. Family?
 
Not to my knowledge, different animal. However knowing what I do now I would tune it exactly the same way I did my AVS2.
 
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I am running a AVS-2 1906 650 cfm on my 5.9 with a Oregan cams roller.
This morning I changed my primary jet from a 95 to a 98 using the same rods... my Wideband says it is now running leaner !
WTF ?
 
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