I'm looking to upgrade my tired old carb. Which way to go, 750 cfm or less, choke, electric or manual doesn't matter, Holley, Carter or Edelbrock, which is best and why?

I have an 84 Camaro, L69......Will have Vortec heads, RPM Performer intake and a mild cam....headers of course........will be a daily driver.....

Thanks again for your help.

 

Gruv,

The Holley #3310 750 CFM vacuum secondary will be perfect. You can buy the electric choke as an option from Holley.

Good luck.

BOR

 

Personally I'd go with a 650, but anyway...

Carter=Edelbrock, same same. I have had holleys in the past, and switched to carters. I wont run another holley. Most people run holleys tho, its really a matter of personal preference I guess. The holley might make a little more HP but I'd rather keep my carter.

Run an electric choke. Manual and heat chokes belong where they came from, the past.

 

I if you get a holley you better be good at tuning carbs. every holley I've EVER had needed retuned about every three months with a complete rebuild about once a year. as one of my friends loves to say, "f*#k a holley!"

 

ok qjest are complete crap strait up!!! i had one , no2 , no 3 of the pos's and none of them ran right! i've had holleys great carbs, but you lose lots of fuel, to change jets, floats stick but they run great!! carter never had cant say ??? i recently had bought my first edlebrock 600 i thought being brand new no trouble...!!! oh i was wrong the first one i got touched nothing.. bolted it on right out of the box! ran OK then it started idleling like a funny car badddd! so took it back and got a different new also 600 cfm! it started ,well it idles for 10-30 seconds and loses rpm and dies??? so i give up you tell me what a "good " carb is? i havent had one!!! ?? i do think 750 a little much on your engine a 750 is like holding a funnel over you intake and dumping the fuel in!!hahha so really dont see the need but please! telll me if you figure out what a good brand carb is let me in on the little secret!!?? please????

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1989 firebird formula

Mods: converted from T.B.I. to a carburator 305 to a 350. Flowmater exhaust,hedman shortie hedders,202 heads,350 horse cam,bored.40 over, Edlebrock torker2 and a 600 edlebrock manual choke.

Future mods performer rpm air gap intake (polished) comp roller cam, and way better headsa 400 defintely in the works!

 

As stated above an Edelbrock is just like a Carter. The Carter AFB (square bore) is a 30 year old design. Edelbrock just improved on it. There's nothing wrong with the Carter/Edelbrock carbs and some people swear by them but I'd prefer a holley myself. The trick to tuning a Carter is to install the largest jets available and swap metering rods to tune it.

If you get a 3310 model, buy a new one not someones 30 year old worn out one.

I run a BG Speed Demon on my race car and love it.

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Follow my racing progress on Stephen's racing page
and check out the race car

87 IROC-Z Pro ET Bracket Race Car
383 stroker (carbed) with double hump cast iron heads and pump gas
461 Big Block installed and ready for the 2001 racing season

Best results before the 383 blew up
Best ET on a time slip: 11.857 altitude corrected to 11.163
Best MPH on a time slip: 117.87 altitude corrected to 126.10
Altitude corrected rear wheel HP based on power to weight ratio: 476.5
Best 60 foot: 1.662

Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley

 

Im having alot of Fun playing with Qjets, and am Having Good Success With them. They are, however, tricky.


The edlebrock/carter AFB clone runs great out of the box In my experiance, I have never Run a holley But have heard alot of good/bad about them. The Demon carbs come highly recommended By three of my friends on 11 second cars.




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60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver

Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype

 

To whom it may concern:

One more time..........

Displacement X max RPM X VE divided by 3456 then multiplied by 1.35 for an average dual plane = CFM

305 X 6000 X .95 divided by 3456 = 679 CFM.

So, use a 750, or, if it's a 5,500 RPM, low-efficiency motor, use a 600.

BOR

 

Exactly BOR, a 600 cfm will do the job. I would use a 600 holley, electric choke, vacuum secondaries for a street car.

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82 camaro--original steering wheel, brake/gas pedals, seats--everything else modified
82camaro

 

I have a 750 edelbrock on my car and it runs great.I have never had a problem with my carb, and they are simple to work on. About 8 screws and some linkage and you can change the jets on these. My car is a 350 and on highway I get around 20 mpg In town and racing around 10 mpg. I prefer a manual choke though.

 

Get a demon!! I will proabably go with a 650 Street demon on my car. But they are a little pricey. $420 for carb + fuel line kit ends up being close to $500.

 

Whatever you get, don't expect it to run perfectly out of the box! It is pretty common to be able to run one out of the box, but there are great advantages to taking the time to tune it properly.

I don't think you would have any problems with a larger carb than you need (Just so that you don't go way overboard) becuase a carburetor runs off the vacuum signals that the engine produces. The vacuum pulls the fuel in, therefore, you only get as much fuel as the engine needs, as long as it's not too oversized (jetting, etc...)

You may want to slide on over to the carb board to see what the regulars there have to say.

Good luck.



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Working on:
'84 Z28 LG4 305 with 200,000 original miles!
Added dual elec fans.
145 MPH IROC Speedo
Building 430 HP 350
using primarily GMPP parts.
Block is STILL in shop! (Waiting for my to buy the rods!)

ASE Certified Master Tech

Starting to look like the Kicker poster child!

 

What is the 1.35 multiply factor. First time I've ever heard of it.

 

JP84Z430HP you are correct that the carb uses a vacuum signal. However, with a big carb and a small engine, the air doesn't flow fast enough(velocity) to pull the correct amount of fuel into the engine. A smaller carb increases velocity. Upper RPM's the big carb will work OK. Around town and moderate throttle, the engine will be lean. If you richen up the jets to compensate for the lean around town driving, it will way too rich in the upper rpm's.

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82 camaro--original steering wheel, brake/gas pedals, seats--everything else modified
82camaro

 

I have the 3310 vac sec Holley 750 and am pretty happy w/ it on my Vortec headed 350 (RPM intake, 218/224 cam, headers, etc). The jets were too big from the factory, and I ended up running a much weaker spring in the vac sec housing and removing the check ball to let it rip open fast enough. I'm real happy w/ it now. I don't know what this retune every 3 months crap is about, mine is just fine. I have a Edelbrock A/F guage and it stays pretty consistent year round here (Georgia). I might have to change the jets if the temps get too far out of norm, but big freaking deal, 5 minutes. Idle mixture set w/ a vacuum guage originally, idles great now. Why this "Holleys are hard to tune" thing? They're simple as **** and you can control just about everything on them...

I would like to try a 650 or so on here to see how different it is though.

BTW, anyone know anything about the new 670 Street Avenger Carb or whatever it's called from Holley?? They describe all these new "easy tune" functions on it but what exactly are they?

------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray


[This message has been edited by Ray87Z (edited February 01, 2001).]

 

'73,

It's the midpoint of 1.2 and 1.5.

That is the multiplier range according to Vic Edelbrock Jr. for a carbed car using a dual plane manifold. For a single plane setup, the range is 1.1 to 1.3, so the midpoint is 1.2 .

And it always works on street cars.

BOR

 

Gruveb, sounds like you have my kind of car, so I had to jump in on this. First off not to diss anybody or start some chit but there is a lot of misconceptions floating around about carburetion. This happens to be my 'thing' so yeah I'm nit-picky about all the concepts.
I happen to run Edlebrock carbs for several good reasons, and so far as my knowledge I'm the only one doing the soup-up mods and supertuning these carbs. If you lived closer then I'd definately let you try out one of my modified Edlebrock carbs and use my Vericom accelerometer to verify the results. At least living in AZ you really do not have to have any kind of choke at all and that gives you a slight performance advantage right there with more CFM and better signal to the primaries.
As a general hint on sizing I will say that I run a #1406 600-cfm carb on my mustang 351C, and a #1407 750-cfm on my camaro 383.
Your 305 should be very happy with a #1406 600-cfm model which is a spread-bore by the way. They are half the weight of a Holley carb and much much easier to modify and tune (depends who you ask). Either way they(Edlebrocks) are far less maintainence than your other two choices mentioned and will definately perform equal to if not better when properly tuned for your combo.
There are tricks that will allow you to run a bigger CFM carb with equal results if that's what you want or what you end up with. Just let me know what you have in mind and maybe I can help.
This is just my biased opinion but I'd put one of my modified Edlebrocks up against about anything out there at double the price.
good luck


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White 1986 Irocz, 305/383 with Edlebrock Performer-RPM intake and Performer #1407 carburetor, +110hp shot of crack, 700R-4 tranny, 3.25:1 rear, Mcreary Road-Stars, single 3" Borla exhaust, Linginfelter-TPI camshaft pulls 17" vacuum solid. N/A runs 10.9 @124, Crack-runs 10.3 @135... haven't run at track since Oct-99

 

I happily run an Edelbrock #1405 (600 cfm manual chocke) which I have converted to electric choke (#1406). Main reason is that the carb was on a Blazer that I got for free. But my brother's friend has a Holley (dont know which model) and he always has trouble tuning the thing. The edelbrock has 3 adjustments...idle mixture, the rods, and the jets. I havent messed w/ different rod or jets yet but i can say my carb performs vey well. I rebuilt in in about 2 hours, it is very simple inside, and as someone said, changing the jets is very simple, you just need to remove the top plate of the carb. rods are even easier, there are 2 little plates on top which unscrew to reveal the rods. personally, this is an ideal carb for me, easy to set up yet it can be made to work great. when it gets warmer i'll start to mess with rods and jets, and the edelbrock website has a great guide to point you in the right direction when you want to tune the carb.

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350, Comp 262, Edelbrock Performer intake 600 cfm carb and exhaust, headers
-JVC, Eclipse, Pioneer, MTX, Phoenix Gold, Planet Audio

 

ODB, you say you do performance work on edelbrock carbs, but dont even know what it is... sad.

The 1406 is a square bore carb, not a spread bore.

 

Well, I've decided to just strap on a rebuilt 650 cfm Qjet off of a '73 Chevy for now. That in conjunction with a HEI Dist, a mild cam, headers and some heads will hold me over while I build my 383.....I cut my costs considerably, although sacrificed a little performance for now, but have decided I can't get the drivable HP and Torque out of a 305 that I desire.

Thanks for the posts.

 

Why worry about CFM? Get a predator carb and be done with it. They are a varible venturi design that meters out the exact CFM your engine needs, from 600 to 900. If your engine needs 679 CFM thats what you get. I recently tried one and fell in love with it. No more holleys or any other type for me and they aren't as many $$ as demon's. And having a square silver box for a carb looks cool too.