Carter Comp carbs.

[Fathead Racing]

It's funny when you get to tear some of the parts you buy on ebay apart. I have to run specific jets and metering rods in my 600 cfm Carter Comp Series carbs for the 409 dual quad setup. When I tore the first carb apart to change the jetting and rods I found that the default jets were in place but someone had replaced one of the metering rods with an Edelbrock piece. That is ok cause we know that the Carter and Edelbrock carbs are one in the same. Where this goes wrong is the metering rods were not even close in size! I wonder if the seller sold the carb because they could not get the engine to run right?? I have three more carbs to tear into. I hope between those three I can find the right jetting and correct size metering rods.

 

[Ronnie Russell]

Ray, I have jets and metering rods out the kazoo. Holler if you need something and I will stick em in the mail. models found me a pair of Carters on e-bay a couple of days ago. When they get here, im gonna check em out, and if there is a problem, I know ole models will send me a refund.

 

[models916]

Huh?

Refund? What's a refund?

 

[Fathead Racing]

Ronnie, same here, I have four of the 600 CFM # 9605S Comp series. If you need the .100" jets I am going to end up with 4 of these. I need Four of the .086 jets now. I'm just getting into the carb setup and need the 7047 metering rods that Curt Harvey recommends. I have the Carter 16-241 rods and think they are the .0705/.047" but haven't confirmed this yet.

 

[Ronnie Russell]

Ray , the 70/47 rods are standard rods for Edelbrock 600cfm-manual choke. I think you are correct about the 241 rods, but will check it out in a short while. Over slept because of that stupid hydraulics discussion.

 

[SS425HP]

overslept

Ronnie, did you oversleep and miss work???????????

 

[tripowerguy]

Ronnie are you saying that math makes you have sleepless nights. Roy

 

[Ronnie Russell]

If you dont use it, you lose it..... Ive lost everything!!!!!!!!!

 

[Ronnie Russell]

Ray, the 16-241s are indeed .0705 x .0475 Ive always been afraid to lean 3 steps. Std jet .095 then .092 .089 .086 . Realize you are getting suggestion from people much smarter than me, but that seems to be on the edge. Dont want to see ya hurt that "sweet thang". Good luck.

 

[Fathead Racing]

Jetting info please.

Ronnie, gleaned that jetting info from Curt Harveys site. I'm lost as to what jetting to use and needed a base line. As for Curt knowing more than you ? I wouldn't take a bet on that. Wouldn't take much to out gun me when it comes to jetting dual quads for my 409, now if it's info you need on three twos Maybe Curt jetted for power on the engine dyno pull and not the real world. I know there is a difference that could make jetting wrong in both cases. I want to hear what others have found. How about it guys, what is working for you?

 

[dq409]

Ray, Thanks,,, I spend my days brain power allotment on your other post :takethat

Now i gonna be dumb the rest of the day

Curt's recommendations are a good starting point but,,,,,,,, I`m WAY up from those jet sizes and I think you will be also.
I would change all my jetting to Edelb specks as their reference chart is really easy to follow and their parts are easier to get.

My sizes are meter rod 7342 with 98 prim jet and 104 sec jet with a silver spring.

good luck,,,dq.

 

[Fathead Racing]

Thanks Jim, I need more imput like this. I'll study on it some more before I make the final decision.

 

[Skip FIx]

Guys after buying a wide band AFR meter I've found all of the Quadrajet jet/rod combos that the Pontiac guys swear by for specific combinations are way off. Even Holley jetting from a similar combimations is way off. Each motor even though close in specs has it's own differences in head flow,cam, and exhaust systems to need a different fuel curve.

Alot of the chassis dynos have them, it's worth your while to dial in carbs and timing on one.

 

[Fathead Racing]

Carter 600 cfm jetting?

Ronnie, I think you misunderstood my post about the .086 jets. I will be starting my jetting with a .095 primary and a .086 secondary with a 7047 metering rod. Does this sound more like it? Or did you know I was talking about the secondarys? If not what do you suggest I start with? One of the carbs came with .100 primarys and .095 secondarys with a 16-241 rod. Maybe I ought to change the secondarys and primarys around and start with .095 primarys and .100 secondarys with the 16-241 (7047) rod!

 

[Garbageman]

Ray, I also followed Curt Harvey's recommendations for my setup. I haven't the equipment, knowledge or money to experiment away from those settings, yet.
I've run the car on the streets and on the track and judging from the color of the plugs it's running just fine. I want to find a chassis dyno to do some fine tuning but haven't found one yet. (Jim do you know of one in Portland?)

I'm chomping at the bit to get the old girl into the 12's but so far I'm running consistent at 13.3 with wild runs at 13.0. Still not bad for a 409 with only a .10 over and hydraulic cam with full interior and a garbageman grabing gears.

Paul

 

[Fathead Racing]

Paul, thanks for your input. What your saying is, you are running with .095 primarys and .086 secondarys and a .0705/.0475 metering rod. Correct ? Do you see where DQ is running a .104 secondary jet? It's tough trying to establish a base line for jetting with all the different setups we are running. Kicking the tranny into nuetral is a nono when you are running an automatic so reading the plugs is probably "out" when at the strip.

Ray.

 

[Ronnie Russell]

No Ray, I did not mis-understand . No way could you use .086 in the primaries. I knew you were talking about secondaries. The last several sets of 600s I have worked on were Edelbrocks. Should be no differance with the Carters. The man. choke versions come with .100 pri, .095 secondaries. (.070x.047 rods) The best combo I have found for dual purpose is .095 pri, retaining the .070x.047 rods. and .092 secondaries.Then you can change to .073x.052 rods to lean another step if you like. That is why I was so surprised about Curts .086 sec. jets. But again, HE IS CURT HARVEY. Its a pretty funny subject with dq usin .104 sec jets. We are all over the place!! It seems logical to start at 1 or 2 steps lean and adjust from there. Since Curt suggest .086, maybe you will want to split the differance and go with .089 sec. And dont be fooled by plug color after a cruise around the block. Even correct jets will darken at low speed. True color shows after WOT. Hope I haven t confused. Good luck.....

 

[dq409]

The way I got to the combo I have is running at the strip and adjusting the jetting by the times i was running.
Jetting up was getting better times with each increase.
You are correct in only changing the jetting a step or two at a time then seeing what the difference is on the times run.
Also do one type of change at a time so you know what worked and what didn`t.
If you change more then one thing at a time you don`t know which one did what.
ie: timing, jetting, launching etc

Ray , you can shift to neutral at the end of your run and coast to the return lane then pull your plugs and check them. I`ve done this several times over the last few seasons.
Did you get that ref chart I emailed you?

Paul, There are several chassie dynos in the portland area.
I`ll get you some numbers, dq

 

[Fathead Racing]

No way am I confused, I'm eating this stuff up. This is much needed information keep it coming guys. Thank you Ronnie, you'll have the chance for a hands on jet change at Clay City, I could use the help.

 

[Fathead Racing]

Kicking into nuetral.

Jim, my tranny guy says that you should not kick the auto tranny into neutral at the end of the run, he says tranny will go into hyperspin inside at that speed and frag something.