Can I make the secondaries kick in sooner?

[WSUTARD]

The car runs great and pulls great. When I floor it I can feel the secondaries open and it pulls like a bat out of hell. However, I was thinking it would be better if I could get them to open earlier on the pedal throw, say at 75% pedal vs 100% (I dont know exactly when they open on the pedal, only that I only feel them when I floor it)

Is there anyway to do this?

Am I making things up?

 

[ScampMike]

"lighter" spring(s) - what carb is it?

 

[WSUTARD]

Eddy 1406.

 

[ScampMike]

Edelbrock Carburetors - Classic Trucks Magazine

 

[ScampMike]

not the be all end all answer - but it's a good read and a great start

 

[yellow rose]

You can open them fast enough to create a bog. If you get them open faster and don't create a bog, I doubt it's worth .01 in E.T.

If you really want the secondaries to come in faster you should use a double pumper. It opens up tuning possibilities

 

[WSUTARD]

Im not even sure what my goal is, other than to feel that kick without slamming all the way.

 

[67Dart273]

^^AS above it's all too easy to open them TOO fast and create a bog. A "jerk" and "wah...uh..WAHHH" when you firewall it is NOT what you want.

 

[Killer6]

The car runs great and pulls great. When I floor it I can feel the secondaries open and it pulls like a bat out of hell. However, I was thinking it would be better if I could get them to open earlier on the pedal throw, say at 75% pedal vs 100% (I dont know exactly when they open on the pedal, only that I only feel them when I floor it)

Is there anyway to do this?

Am I making things up?

The secondaries have counterweighted air-valves above the throttle blades, what you're hearing is the air-valves doing their job. Making them open sooner may be the
worst thing to do, and it's a royal PITFA to fine tune & get right................that's if it's not already...You would have to either add or remove weight to change the opening
rate/timing. Your own words....."runs great and pulls great.".........if You've achieved that with an OOTB Eddy Perf. I say leave well enough alone & save any changing for
rods/jetting etc.............................otherwise buy a DP & get it over with.

 

[RustyRatRod]

The smoother the secondaries open, the faster the car usually is. So, if you get the carburetor to where you cannot......or just barely can feel them open, that's about right.

 

[Johnny Dart]

No, you have a vacuum secondary carburetor......Get a book, and read.

 

[MopaR&D]

You should be able to feel a point in the gas pedal travel where the carb starts to open the secondaries about 2/3 to 3/4 way to the floor, but like others said the air doesn't start flowing into the engine until it needs it because of the weighted air door. Check the linkage with the car off, have someone slowly push the gas pedal to the floor while you watch the carb linkage and make sure it goes to full open, you should also see the linkage that opens the secondaries as it moves.

It's kind of nice to know where that point is so you can save a bit of gas when you want to get moving quicker or pass someone but don't need 100% power and the extra gas that goes with it.

 

[Lustle]

Im not even sure what my goal is, other than to feel that kick without slamming all the way.

Your goal should be no kick at all.

As "cool" as it is to get that kick in the pants from the secondaries opening. It's a sure sign of a badly tuned carb. If you can feel the secondaries open that means either you had a lean/rich situation before they opened, when they opened or after they opened. Hence the engine "surging" with the secondaries opening. With a properly tuned carb, you shouldn't get a "kick" when they open, because you aren't getting a lean/rich situation, it should be a smooth transition. That mean's you have the proper air/fuel ratio through the entire opening of the secondaries. You might hear them open, sometimes when the secondaries open they create a loud suction sound. And you'll feel the engine pull hard and can tell its gaining RPM faster than when the secondaries aren't open. But that's the whole point of them isn't it?

 

[jockeyshift]

There is an articale in Chrysler Power Mag from Dan Dvorak on eddy carbs.That tells how to open sec.faster

 

[Killer6]

No, you have a vacuum secondary carburetor......Get a book, and read.

That is inaccurate, vacuum secondaries use vacuum to operate the throttle valves, and can be tuned by controlling the vacuum pot doing the actuating.
The secondaries on this 1406 performer are mechanically operated, and there are COUNTERWEIGHTED air valves above the throttle blades that are
calibrated to maintain air velocity and booster signal. If it's right for Your combo, You're good, if not You have to trim/add weight.....PERIOD.
The description for this carb is mild performance & economy, YES....buy a book & learn what to do, YES buy a re-calibration kit and test & tune for
best performance, NO don't just trust the Butt-o-meter unless it's literally showing evidence(winding higher/knocking the tires loose easier/etc.).

 

[Johnny Dart]

Start shaving the couterweights, I dare you.
Hope you know what you are doing, because if you dont, you just built yourself a new door stop. Looking forward to your results.

 

[WSUTARD]

All this has been very informative, except for Johnny Dart's comments.

I am going to pay more attention to the feel and when I get it. I obviously feel more power around 3500-4000. But as Rusty said, I would like for this power to smooth in starting around 3000 instead of 3500.

I understand carbs a tad, there just seems to be a ton of linkages that could be loose, which is why I originally asked.

Now, all this goes away if I can figure out a way to sneak a FiTech on the credit card without the wife knowing.

 

[Johnny Dart]

All this has been very informative, except for Johnny Dart's comments.

I am going to pay more attention to the feel and when I get it. I obviously feel more power around 3500-4000. But as Rusty said, I would like for this power to smooth in starting around 3000 instead of 3500.

I understand carbs a tad, there just seems to be a ton of linkages that could be loose, which is why I originally asked.

Now, all this goes away if I can figure out a way to sneak a FiTech on the credit card without the wife knowing.

Waaaa...Lets call the Waaabulance.
Really....You disagree with a big red X, because I recommend getting a carburetor book and reading ?
Probably the best advice you could get. Sorry you are so thin skinned. I'll take note next time.

 

[WSUTARD]

Waaaa...Lets call the Waaabulance.
Really....You disagree with a big red X, because I recommend getting a carburetor book and reading ?
Probably the best advice you could get. Sorry you are so thin skinned. I'll take note next time.

It's not what you say, its how you say it. BTW, who has the thin skin?

 

[Killer6]

Ok rookie nut swinger's with the red X's...Start shaving the couterweights, I dare you.
Hope you know what you are doing, because if you dont, you just built yourself a new door stop. Looking forward to your results.

LOL, First spunky, I didn't disagree with getting a book on tuning said Eddy/Carter carbs, just the incorrect "vacuum secondary" statement...which is in fact
incorrect. Second, I didn't recommend doing anything with the weights because they may be fine as is, but that is the only way to make them open faster/slower..fact.
You seem to have a selective reading &/or comprehension issue, but go ahead and take dumb-*** potshots at Me Sport, I've been at this plenty long enough to know.
The 1406 is not the performance calibrated version of that carb, so it isn't even the right carb from the get-go, it may or may not be made to perf. optimally. Many
have trimmed or added weight to the secondary air valves to fine tune them, and guess what? It f**kin' works, but it's a PITFA as I clearly stated, and only IF needed!

 

[Killer6]

Actually, even what I just stated isn't 100% correct, optimizing the jetting & timing will open the air-valves more quickly by the fact the engine will be generating a
stronger vacuum signal for a given RPM & load condition................................

 

[RustyRatRod]

That Edelbrock carburetor is a MECHANICAL secondary carburetor. That means when the throttle is WOT, ALL FOUR barrels are open, regardless of engine RPM, or vehicle load.

They are AFB carburetors. That stand for Air Valve Secondary. All this means is, the secondary barrels have an air door placed above the secondary throttle plates to regulate air flow. That air door DOES NOT control throttle plate operation, it only controls incoming air.

A vacuum secondary carburetor uses vacuum to OPEN the secondary throttle plates. The AFB is not such a design.

 

[Killer6]

LOL,RRR!!!, where were You back at post#15?!?!?

 

[Johnny Dart]

LOL, First spunky, I didn't disagree with getting a book on tuning said Eddy/Carter carbs, just the incorrect "vacuum secondary" statement...which is in fact
incorrect. Second, I didn't recommend doing anything with the weights because they may be fine as is, but that is the only way to make them open faster/slower..fact.
You seem to have a selective reading &/or comprehension issue, but go ahead and take dumb-*** potshots at Me Sport, I've been at this plenty long enough to know.
The 1406 is not the performance calibrated version of that carb, so it isn't even the right carb from the get-go, it may or may not be made to perf. optimally. Many
have trimmed or added weight to the secondary air valves to fine tune them, and guess what? It f**kin' works, but it's a PITFA as I clearly stated, and only IF needed!

I stand corrected, I always thought the Ede's were considered a vacuum secondary carb, with the function of the counter weights. I know that 60's-70's drag/street racers use to shave/add weight to fine tune their Carters. But as stated, it can go south quickly. So I guess this is the answer to the question.
Yes you can, but you better know what you are doing. To the original poster, I sincerely wish you luck on your quest.

 

[Killer6]

It's all good Dude, Hey, when the red X's start flyin'!! Lol! As long as WSUTARD understands what He's about to get into if decides it's needed, He has been warned, or just
throw a Quick-Fuel 650 on it & be done! OOOpps!! Did I say that out loud???