Carb recomendation

Posted By: moparmatt383

Carb recomendation - 06/06/08 05:27 AM

Hello,

I have a 73 Cuda and was wondering if you guys had some imput on a carb. Here is my set up:

340
KB Pistons
Edelbrock performer RPM cam
Ported J heads with 202 valves
Edelbrock Air Gap RPM intake
Chrome iginition box
Hooker super comp headers
4 spd
3.55 rear end.

I currently have a 600 edelbrock performer carb and I want to go to a demon.

Any thoughts on which demon? This is a street car.

Matt

Posted By: gch

Re: Carb recomendation - 06/06/08 10:27 AM

sounds like a pretty good setup in a cool car.
I never had much luck with tuning my demon.I have always had good luck with holleys.
I think a 650 or 700 would work well.You can pick up some pretty good deals in the swap meet section.

Posted By: Exit1965

Re: Carb recomendation - 06/06/08 01:12 PM

If I were you I would register at hotrodders.com, and find a guy named "Tech @ BG" -- he is a helpful guy and will recommend a carb for you. The phone service at BG is notoriously lousy and rude, but this guy is an exception but I don't know his phone #.

For my

, with that cam it calls for the mighty demon, and the smallest one they make which is 650 CFM. They flow more than that. For my 440 they recommended the 750 CFM mighty demon, OR the 800 CFM annular discharge since some of the flow is restricted by the larger boosters. I went with the annular, and after 45 minutes taking the carb apart, finishing up the drilling they didn't complete (partially drilled holes in metering blocks), removing small flakes of metal that were hanging ready to come off (in metering blocks and body), then blowing the whole thing out, I'm happy with how it runs.

Count on taking it apart and going through it.. BGs reputation for bad QC is deserved (my carb was bought new a couple months ago, so the QC problems still exist).

Posted By: dwbiggs

Re: Carb recomendation - 06/06/08 07:43 PM

Quote:

Count on taking it apart and going through it.. BGs reputation for bad QC is deserved (my carb was bought new a couple months ago, so the QC problems still exist).

Thats pretty amazing...I started hearing about their quality issues years ago, you would have thought they would have them under control by now.

Posted By: Exit1965

Re: Carb recomendation - 06/06/08 08:03 PM

Quote:

Quote:

Count on taking it apart and going through it.. BGs reputation for bad QC is deserved (my carb was bought new a couple months ago, so the QC problems still exist).

Thats pretty amazing...I started hearing about their quality issues years ago, you would have thought they would have them under control by now.

Yeah, I would have thought so too. At least mine wasn't full of metal shavings as they used to be famous for. Perhaps they are getting better, at least washing the shavings out now, just not bothering to remove hanging metal slivers or drill holes completely.

Posted By: torkrules

Re: Carb recomendation - 06/06/08 08:52 PM

Quote:

Quote:

Quote:

Count on taking it apart and going through it.. BGs reputation for bad QC is deserved (my carb was bought new a couple months ago, so the QC problems still exist).

Thats pretty amazing...I started hearing about their quality issues years ago, you would have thought they would have them under control by now.

Yeah, I would have thought so too. At least mine wasn't full of metal shavings as they used to be famous for. Perhaps they are getting better, at least washing the shavings out now, just not bothering to remove hanging metal slivers or drill holes completely.

I went through 2 Holley carbs (one 870 Street Avenger and one 3310 750). I'm pretty carb savvy, but I could not get either of these to work properly. I've always sworn by Holley's and I'm sure the HP carbs are excellent as are the double pumpers. I tried to find one in stock, but all anyone had was a BG speed Demon 750. I've heard so much about the problems with these carbs, but I was desperate.

I've got to admit, it does work awesome. I had to open the idle feed restrictor up a couple of thou to get rid of a lean surge at cruise speeds, but it is really responsive and has some nice features. Just my

Posted By: DemonKyle

Re: Carb recomendation - 06/07/08 12:21 AM

Demon carbs, when drilled right and not full of shavings, run awesome.

Having said that, I am proud to have a Holley 750dp on my car after my own problems with BG carbs causing it to break engine parts.

Just know that Demon carbs are underrated about 70-80 cfm. So a 650 mighty demon will actually flow about 720 which in my opinion should run amazingly on your car

Posted By: mark7171

Re: Carb recomendation - 06/07/08 12:32 AM

demon carbs are great, they can do what a holley can do. same weakness in the secondaries, you have to keep it pulling the secondary's fuel, otherwise it gets flat.

that edelbrock has a rod spring thing you get right and it works fine. the mechanical nature of the secondaries is a big plus. its also underated 50 cfm or so, actaully the performer flows closer to 650cfm. if you want to unload the edelbrock let me know? a guy accross the way has a 73 GTO. he wants me to rebuild a carb for him. let me know, PM me.

i cant recommend anything that you have to drill to work on your application. a demon is expensive too.

Posted By: MY340

Re: Carb recomendation - 06/07/08 11:22 AM

Have you thought about a Thermoquad carb? I use a chokeless 850cfm TQ carb on my built 340 Duster. The difference in the topend is fantastic compared to a 600-650cfm carb.

Posted By: mark7171

Re: Carb recomendation - 06/07/08 01:01 PM

but thermoquads arent cool.

how about a carter AVS?

Posted By: terzmo

Re: Carb recomendation - 06/07/08 04:14 PM

650 CFM would be best

Posted By: moparmatt383

Re: Carb recomendation - 06/08/08 02:54 PM

Ah so many options! Some people that I talk to locally swear by demons so that is why I was leaning in that direction but I am not dead set on one. For my car would you recomend mechanical or vacuum seconderies? Also is a demon mech secondary carb the same thing as a holley double pumper?

Matt

Posted By: JUST_N_TIME

Re: Carb recomendation - 06/09/08 01:13 AM

for your application a 650dp Speed demon should do the trick nicely.

Posted By: 451Mopar

Re: Carb recomendation - 06/09/08 05:39 AM

Check out the proform 750 vacuum secondary.
These are actually pretty nice and reasonably priced.

http://store.summitracing.com/partdetail...mp;autoview=sku

Posted By: Rug_Trucker

Re: Carb recomendation - 06/09/08 03:46 PM

Quote:

but thermoquads arent cool.

how about a carter AVS?

See sig line...........you're behind the times

Posted By: moparmatt383

Re: Carb recomendation - 06/17/08 10:03 PM

Another question. Are the demons that say they are mechanical secondaries the same as a holley double pumper where all 4 brl are opening all the time?

Posted By: DemonKyle

Re: Carb recomendation - 06/17/08 10:10 PM

Quote:

Ah so many options! Some people that I talk to locally swear by demons so that is why I was leaning in that direction but I am not dead set on one. For my car would you recomend mechanical or vacuum seconderies? Also is a demon mech secondary carb the same thing as a holley double pumper?

Matt

Heres the difference between vac. sec. and mech. sec. as I was told by an old racer friend...

Vacuum Secondary= Gas Mileage, moderate performance.

Mechanical Secondary=Performance, moderate gas mileage.

If you want the performance when you hit the throttle, go with a double pumper. If you want gas mileage, go with a vacuum secondary.

The demon mechanical sec is just like a dp. Like stated above, a 650 mighty demon mech. sec. will work amazingly on your car. Just clean the **** out of it first

Posted By: Anonymous

Re: Carb recomendation - 06/17/08 10:55 PM

Quote:

but thermoquads arent cool...

niether are you.

anyways,

I'd go TQ. BUT if you don't wanna use a spreadbore intake/adaptors..
go 700+cfm holley DP. 4-speeds LOVE DP carbs. BARRY GRANT carbs just plain SUCK.