Dialing in my Holley Carb

[Flatsman]

Thanks Railroad for your input, I believe you are tight with the wb being a tool and all, it does come down to the sotp. You mention your combo with the 600, I would be willing to bet this avenger carb has a puny pv restriction channel, I'll know when I pull the primary metering block off. These avengers were Holley's answer to some of the more universal carbs they offer being so rich out of the box and have been very well known to be lean on most all instances, I may be speculating wrong here though. I have thee black spring in the seconday vacuum , so they dont offer a stiffer one Im told. Im banking on the flat spot being still in the primary, would explain why the secondary jets are 10 sizes over just to get a 12.5to1 af. stock were 68 and I put some 80s in there

What language are you Guys speaking??? You are way out of my league!

 

[sstock]

What language are you Guys speaking??? You are way out of my league!

Cmon Fred, you flew jets for a living,lol. There are jets in carbs, it is the same thing right,haha

 

[railroad]

Go back to your disconnecting or blocking the secondaries from opening. Tune the primaries for good drivablity without the WB. If you are 10 jet sizes over on the secondaries, you need to go back to square one on the secondary. I cannot believe they are even opening with the black spring. You may not need this, but here is an attachment that will ballpark the spring tuning. You need a passenger to watch the secondary linkage to make sure it is opening and what the car is doing when it does. The stock jetting on your engine should not be more than 2 sizes, plus or minus from ideal, even on the WB.http://www.holley.com/data/Products/Technical/199R8219-2.pdf

 

[railroad]

Here is another good site, when I think I know it all, I read it again.
http://www.bob2000.com/carb.htm

 

[Screaming Metal]

SS, heres something you might also want to consider. You've put in alot of work, and its just right when the transition is , just before the large vacuum drop as the rear 2 open...right? They have a blockoff plug for the powervalves. Most of the time you don't need them, but, I have used them before under extreme conditions. Just does away with that one feature of the Holley Carb. But, it eliminates that problem.

I'm going back to reread everything to see if I missed something....

 

[Screaming Metal]

SS, just ignore my last post....you have put in a ton of work into this carb and its still giving you fits....ask you gearhead friend if he's got a dual feed 650 doublepumper he's let you try. I believe if you put that on there, you'd be fairly close, at least you wouldn't have the huge Bog....just before the rear 2 opened up.
If you go this route, pay attention to your power valves....
Depending on your compression, size if your intake valves, cam, and header dia. size, you might even want a 750 DP'er.... if your motor is pretty stout.

 

[Flatsman]

Thanks Railroad! I saved both of your links to my favorites and will read them when I am not under the influence of one of my Big Boy Margaritas! Have a great weekend.

 

[railroad]

Thanks Railroad! I saved both of your links to my favorites and will read them when I am not under the influence of one of my Big Boy Margaritas! Have a great weekend.

Every man has to have his priorities, good choice.

 

[sstock]

SS, just ignore my last post....you have put in a ton of work into this carb and its still giving you fits....ask you gearhead friend if he's got a dual feed 650 doublepumper he's let you try. I believe if you put that on there, you'd be fairly close, at least you wouldn't have the huge Bog....just before the rear 2 opened up.
If you go this route, pay attention to your power valves....
Depending on your compression, size if your intake valves, cam, and header dia. size, you might even want a 750 DP'er.... if your motor is pretty stout.

Ok, the carb saga is over. Done fussing with this Holley Avenger vacuum secondary, never could get enough fuel in her at the secondary opening point to stop the lean bog issue unless I had a good amount of engine speed in it, like over 3000rpms.
I finally broke down and took Screamings advice and took a hammer to the vacuum secondary carb after bolting on the Quick fuel 650 double pumper with annular boosters. Wow what a difference, this thing rocks, by far the best carb I have bought in my 54 years and I have bought a few. I cant say enough good about an annular booster, it picks up the signal so much faster on the seconday and noticed the transition from idle to main metering to be very seemless. Interesting thing about this, I got by with the stock secondary shooter and used a much smaller shooter on the primary side (.045) too than what I was using on that avenger carb.. The idle mixture was set with the wideband, a much better way than the vacuum gauge, and I had to lean the main jet from 68 to a 67 to get the cruise right where I wanted it. I left things a tad richer than normal because of the plenum size. The pvrc I leaned a tad to get the A/Fs in the mid 12s when vacuum drops and opens the valve. WOT with secondaries I haven't played with yet because I cant hold the WB and read it and control the car at the same time, this little 301 chevy just got scarey to drive. Thanks all for the help. BTW, the Carb is a SS650AN.

 

[Screaming Metal]

Tape it to the windshield and go for that cruise! Hahaha!!!! Bet she has some throttle response now!

 

[sstock]

Tape it to the windshield and go for that cruise! Hahaha!!!! Bet she has some throttle response now!

Thanks all for the input, finished up on the tune today,
Here is how it ended up:
Quickfuel SS series 650 double pumper with annular boosters on a Weiand 3984 single quad street tunnelram
Idle mixture set warm at 13.4 A/F
Main jet changed from 68 to a 67 then ended up with 66. Cruise A/F 14.2
Main squirter changed from a .033 to a .035 to a .040 ended up with a .045 W hollow screw to get the tip in crisp with no hiccups
50cc accelerator pump on the primary side
Power valve changed from a 6.5 to a 8.5
PVRC changed from a .049 to a .059 A/F on steady load 4" of vacuum 13.2 A/F
Secondary squirter changed from a .031 to a .035, no opening bog
Secondary Jet changed from a 74 to a 77 A/F full on 12.7
Think I have more time in tuning than building the entire bucket.
Hitting Holley 570 Avenger with a big hammer now

 

[Flatsman]

You must be really good at taking your carb on and off your car! I just rebuilt my two 450 cfm 9776 Holleys but haven't started the car up yet. I know who to call now if I have questions! Good job and it shows you have a lot pf patience!

 

[Screaming Metal]

Hahahaha....felt Good, didn't it? Glad its straight for ya! I know those single 4 tops are great for the low end torque and throttle response, in the jet drive boats...

 

[sstock]

You must be really good at taking your carb on and off your car! I just rebuilt my two 450 cfm 9776 Holleys but haven't started the car up yet. I know who to call now if I have questions! Good job and it shows you have a lot pf patience!

Fred, I could take the carb off and then the fuel bowls off in my sleep.
Good luck with yours, keep me in the loop.

 

[sstock]

Hahahaha....felt Good, didn't it? Glad its straight for ya! I know those single 4 tops are great for the low end torque and throttle response, in the jet drive boats...

Real happy with it Screaming, thanks for your time/expertise helping out, I know you had some long posts--appreciate it a ton.
Steve