edelbrock jetting

[jester]

Can anyone direct me to the thread or web site that will tell me what size jets go where in the 600 cfm edelbrocks. Its a 64 409, 425hp. I'm running a manual choke in the rear and the auto. choke in the front.
Does anyone know what set up works best?

[Ronnie Russell]

jester, Manual choke in rear and elec. in front?? A strange combination. Which choke is active? Manual choke carb has .100 jets primary------- .095 secondary with .070x.047 metering rods Has orange meter. rod springs..... Electric choke carb had .098 primary and .095 secondary. .075x.047 metering rods. Has yellow meter. rod springs....... If I might suggest, Use active choke in rear,,,, remove choke from front. For your particular car , I would recommend .098 primary .092 secondary with .075x.047 rods in both carbs. This is just an opinion and others will probably voice their own suggestions. Hope this helps :)

[dq409]

Can anyone direct me to the thread or web site that will tell me what size jets go where in the 600 cfm edelbrocks. Its a 64 409, 425hp. I'm running a manual choke in the rear and the auto. choke in the front.
Does anyone know what set up works best?

Disconnect the choke on the front carb.

It would be a toss up which choke works better but IMO I would use the manual on the rear carb, remove the choke plate on the front carb and plug the holes where the choke plate rods were.

I think you will find that you will very seldom have to use the choke. dq

[jester]

Thanks for the reply. I had the auto choke in the rear but reversed them because I wanted to run a little bit richer. I also went two stages richer in the power mode with the 070X037 metering rod. I went with the pink springs because the motor only has 10" of vacuum. I never use either of the chokes. There on there because I never bothered to remove them. I plan on setting up the front carb as close to the specs. in the rear as possible.
Am I at least heading in the right direction with this or should I just re-install the stock rods and springs and put the manual choke carb back where I had it ?:rofl

[pauls63409]

I use two 600 manual choke carbs on mine. I have the rear one set up to work as I need it to start the car when the engine is cold especially in the notheast part of the country where the temp is cold this time of year. My car runs great. Good luck, I think your heading in the right direction.

[fatride]

I can never figure out why anyone would use the manual choke over the electric unit! I have ran both and by far have found the electric choke to be superior. Summer or cold weather starts are automatic! I have the electric choke on the rear carb and have removed the front choke assembly. Listen to Ronnie as he is the go to guy when it comes to jetting the AFB style carbs.

[jester]

Well, thats good enough for me. Thanks for the help.:rofl

[pauls63409]

I can never figure out why anyone would use the manual choke over the electric unit! I have ran both and by far have found the electric choke to be superior. Summer or cold weather starts are automatic! I have the electric choke on the rear carb and have removed the front choke assembly. Listen to Ronnie as he is the go to guy when it comes to jetting the AFB style carbs.

Seem to be able to controll cold start up better. Running high lift long duration cam and runs pretty rough till it warms up a little. Electric choke does work well but I prefer manual. Guess I am just a controll freak. Never really had a problem with it and everything seems to be just right. You know what they say, "Some like chocolate and some like vanilla." I like both. Have a nice day.:)

[dq409]

You know what they say, "Some like chocolate and some like vanilla." I like both. Have a nice day.:)


With Vanilla you can ADD chocolate syrup !!!! With chocolate you can`t remove the chocolate to make vanilla !!!!:doh

This is why I like the manual choke !!!
It only works when you want it to !! ,,,dq :D




.

[fatride]

Seem to be able to controll cold start up better. Running high lift long duration cam and runs pretty rough till it warms up a little. Electric choke does work well but I prefer manual. Guess I am just a controll freak. Never really had a problem with it and everything seems to be just right. You know what they say, "Some like chocolate and some like vanilla." I like both. Have a nice day.:)

Now I know why! Thank you. Do you run your car at the strip Paul?

[pauls63409]

Now I know why! Thank you. Do you run your car at the strip Paul?

As a matter of fact Fatride I don't. At least not anymore. I restored the car and put alot of time and money into it and I don't want to screw it up. I had more fun with it before I restored it. At Cecile County in Maryland about eight years ago, I managed a 13.4 @ 104 mph with street tires and no tracktion bars. I could not hook up without going sidways so I walked it out of the hole at 1000 rpm then nailed it. The cam came on around 3000rpm and it pulled like crazy. It felt great. I know the car is capable of the high 12's if I could get to hook up. But low and behold I have but one 409 and I don't want to damage it or the rear. If I was able to get it to hook up that day I would have probably twisted the rear out. That happened to me one time in another car. So there you have it, I am a big fat p_ _ _ _ but I love my car and the way it sounds and rocks and rolls. Paul :)

Happy Thanksgiving !!!

[dq409]

So there you have it, I am a big fat p_ _ _ _ but I love my car and the way it sounds and rocks and rolls. Paul :)

Happy Thanksgiving !!!

:rofl :rofl :rofl

Thats all that counts !!!!!:rofl :D

[jester]

Hay, remember me?
OK, It's all back the way it was. The auto choke in the rear and the jetting and rods are as they were when they came out of the box.
I just have one or two more stupid questions.
Where have you guys wired the positive side of the electric choke?
Does the wire stay hot all the time,
Thanks again for all the help.:rofl

[fatride]

Positive side of choke wire must be hooked to wire that is hot only when engine is running, not when key is in on position. Yes when engine is running choke wire is hot always.

[jester]

I'll be heading out to the big garage this morning. I need to stay out of the kitchen while the bird's in the oven. If I pick to much before dinner, Nasty will wack me with the broom again.
I'm going to wire that choke and see what happens. Thanks again for the help.
P.S. everyone, have a happy Thanksgiving.:rofl :rofl

[pauls63409]

:rofl :rofl :rofl

Thats all that counts !!!!!:rofl :D

I love this guy !! If you are half as crazy as you seem, your my kind of guy.!!
If you drive a H D I know where your head is at. :):)

[desapience]

I read this thread through... and it seems no-one mentioned why only the back carb (on a 4x2 409/425) was choked, and not the front carb.

It matters little what type of choke system is used (electric or manual), but, what does matter is if the 4x2 linkage is set as being progressive or diect to both carbs.

If you abolutely do need a choke system, and IF you have set your 4x2 linkage to be direct -- non-progressive -- you'll need to place a choke system on both carbs for it to work correctly. If you set the 4x2 linkage to progressive, then, only the back carb needs choking.

Why you ask?

In a progressive set-up, the initial throttle travel only operates the rear throttle plates and squirters (opening them), while leaving the front carb's throttle plates closed. Thus, choking the rear carb alone still chokes off all air-flow (making for a richer mixture), despite its throttle plates being partially opened. The front carb is intially not coming into play and with it's throttle plates remaining closed (initially) which does not interfere with the combustion chamber's enriched start-up mixture.

My 446 is set-up as non-progressive (direct), and I have devised a neat set-up to choke both carbs equally, using a manual choke cable. Thing is, it's not ever really cold enough here in FL to need a choke of any kind. If I was to go to a progressive set-up, I'd definitely go to an electric choke on the rear carb only.

Just my 3 cents worth here... inflationary stuff.

Denis

[dq409]

Denis, I think that is over kill.

Just having the rear carb choked, IMO, is enough to start any dual carb setup.dq

[MRHP]

Since at low speeds you only use the rear carb, as intended at the General. The choke is only needed in the rear. The intake will deliver the fuel and air adequately for low speeds through one carb. I have no chokes on either carbs of my dual quad set up. I do have to "babysit" the car on initial fire up for a minute or two. I can live with that.My straight linkage throttle response is 47 times better than progressive linkage.:D

[Ronnie Russell]

dq,,,,,,, "over kill " from Denis???????? If Denis could get 3 or 4 chokes on a 2x4 intake ,,, he would!!!!!! :rofl :rofl :rofl

[desapience]

Denis, I think that is over kill.

Just having the rear carb choked, IMO, is enough to start any dual carb setup.dq

Sure, at low speeds, and partial throttle start-ups -- IF the 4x2 linkage is set progressively, only the rear carb's throttle plates are opening - AND, the front carb's are not opening. That's why only one choke on the rear works so well.

But, if the linkage is non-progressive (as in my 446 stroker), then you have both carb's throttle plates opening at the same time, ALWAYS!! Thus, choking only the rear carb will NOT be near as effective as choking both, in this context. You'd be functioning almost as IN-effectively as a single 4-barreled car with no choke at all (assuming very cold starts)!

It's not a matter of overkill at all... you either are going to design your system to have a properly functioning choke system, or not.

As for my 446, I never use the dual choke system (here in FL). But, it is designed to start anywhere, including where igloos are common-place.. and like posted above, I too babysit the car a minute or two at startups, but, with non-progressive carb function, the performance and response are both lightening fast -- immediate -- and far better than any progressive set-up!!

My upcoming 482 with the M/T crossram (see "Let the build begin" thread), would need dual chokes (electric preferred) in a very cold envoronment -- but, I'm not moving to anywhere cold, ever...

Denis