Serious Q: Re: Carbs., Running moderate cammed 350 SBC Options

[Dr. Roger]

Got two vac secondary carbs (600 cfm smog carb and a 750) which I now know are in need of rebuilds.

The 600 runs but, on this heavily cammed engine, like *hit. Idle circuit has very little adjustability. And it's got more vacuum ports than I can count.
The 750 is a bit too much I think for the 350.

I've run 650 double pumpers with great success and am thinking about installing a 650 spreadbore. Small primaries/large secondaries.

Goal here is to keep higher velocities off idle for responsiveness and, due to engine displacement, not over carb it like if I used the 750cfm. 6K redline...

I'm about ready to go the the local parts place and plunk down some spare change on a new 650.

WWYD? =-))

Roger

Pic is the 600 smog carb....... Come hear it run.... Swap ya' for that old 650 dbl pumper..... =-)))

[skline]

I am running the Edelbrock 650, it works great, easy to adjust and it is made by Weber. Joe Buckle is running the same carb on his and I know a few others that also run that carb, It's like $200 and good to go out of the box. The only other option I would consider would be the AVS series. Adjustable valve secondaries, still the same size though.

[Dr. Roger]

QUOTE (skline @ Aug 29 2005, 11:23 AM)

I am running the Edelbrock 650, it works great, easy to adjust and it is made by Weber. Joe Buckle is running the same carb on his and I know a few others that also run that carb, It's like $200 and good to go out of the box. The only other option I would consider would be the AVS series. Adjustable valve secondaries, still the same size though.

Where can I get one that cheap in the Bay area? Cali?

Thanks!!

Roger

[Sammy]

It all boils down to what you know.
Holly carbs are popular because they are simple to fiddle with, but are notorious for flat spots and are not the most accurate. I don't like them. The only ones I ever got to work perfectly on high performance engines were the 660 center squirters (dual quad, big $$).

the edelbrock carb is basically a new version of the carter AFB (a la chrysler), they are a little tougher to dial in than a holly but work better when dialed in. You can find them at any speed shop and some flaps like pep boys, I've seen em for around $280. If you can get one for $200 that is a smoking deal. Because they are new and should be close to dialed in out of the box, they are almsot a bolt on.

Then there's my favorite, the Rochester quadrajet (chebby) spread bore.
I am in the minority but I think they are a very good carb. Sure they are a real PITA to dial in but once setup they meter very good for a 4 bbl.
Downside to them is the metering needles and having to pull the top off the carb to make changes.
On my V8 car the carb i had on the car sucked so I went to the pick a part and found an 800 cfm speadbore quadrajet for $25. It only took a little tinkering to get it to run just right.
Plus the sound when those huge secondaries open up is just too cool. Whhhooooooooooo!

[Dr. Roger]

QUOTE (Sammy @ Aug 29 2005, 11:45 AM)

It all boils down to what you know. Holly carbs are popular because they are simple to fiddle with, but are notorious for flat spots and are not the most accurate. I don't like them. The only ones I ever got to work perfectly on high performance engines were the 660 center squirters (dual quad, big $$). the edelbrock carb is basically a new version of the carter AFB (a la chrysler), they are a little tougher to dial in than a holly but work better when dialed in. You can find them at any speed shop and some flaps like pep boys, I've seen em for around $280. If you can get one for $200 that is a smoking deal. Because they are new and should be close to dialed in out of the box, they are almsot a bolt on. Then there's my favorite, the Rochester quadrajet (chebby) spread bore. I am in the minority but I think they are a very good carb. Sure they are a real PITA to dial in but once setup they meter very good for a 4 bbl. Downside to them is the metering needles and having to pull the top off the carb to make changes. On my V8 car the carb i had on the car sucked so I went to the pick a part and found an 800 cfm speadbore quadrajet for $25. It only took a little tinkering to get  it to run just right. Plus the sound when those huge secondaries open up is just too cool. Whhhooooooooooo!

OK, best deal so far is $280 for the Edelbrock 650cfm.

Manual choke and out of the box ease of installation/adjustments. Remove the top of the carb for needle replacements and other adjustments. Don't have to dissassemble it.

If that's the best deal, then I'm on it. Sold. =-) (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif)

[skline]

$280? I just got mine about a year ago and it was only about $209.00, did they go up recently? I will do some checking, I got some new catalogs the other day.

[skline]

Well, I guess they did go up a little. I am looking at the new Jeg's catalog and the manual choke version is $245.99 and the electric choke like I have is $265.99. The 750 manual choke is $265.99 and the electric choke version is $281.99. However, they have factory refurbished ones for $199.99 all manual chokes. The 500 CFM is more money at $269.99, I dont understand that.

[Twystd1]

Barry Grant Carbs... PERIOD. Go to their website and see their offerings.

If you tell them your engine specs. they will build a carb specifically for your needs.

They almost always work VERY WELL, right out of the box..

In my humble opinion. These are better than ANY off the shelf carb.. Hands Down.

Demon Carbs

Ya gets what ya pay for.....

Dats my .02 worth...

Twystd1

[flatout]

Yes, I agree I run 2 race demons on my blower motor. They can be tunned at all four idle screws, and I can change the cfm flow by changing the venturi barrels. Love them. I also had a single speed Demon on a street motor.. The price is a little more but well worth it. NO bog and quick excel off idle thru the whole rpm range.

[messix]

throw and rebuild kit on the 750 holley. that 600 emisions carb is junk. the 750 will work good, the bigger carb helps if your not running a carb spacer because the slower air fuel mix turns into the runners with out slamming in to the intake floor first. [what intake are you using?] i had this problem with a 400 hp 350 once, it idled like crap and just wouldn't get off the line well. i couldn't use a carb spacer to smooth the flow in to the runners because of hood clearance and tried the bigger carb and that did the trick.
get a holley build book that shows how to adjust and rebuild these that will help you tune it. shouldn't take much, pay attention to the float level and fuel pressure, holleys are picky with that, oh and they go hand in hand; rais the pressure and the fuel level goes up and your mixture gets richer. use a fuel pressure regulator also and run at 4psi this gives good float stability.

holley carb arent that bad, i run one on my jeep off road it passes emissons and runs steady on very steep hillclimbs and even runs with the jeep laying on its side. i have done alot of easy work on this to get it there and now they come out with the're truck avenger carb that has all the mods that i did to mine.

good luck post any problems or pm me and i'll help you get thru them.

[914GT]

A nice advantage of the Carter AFB/Edelbrock Performer is that you can use a full-size round air cleaner with it and it will still clear the engine lid with no modifications. Other carbs may be OK too but I know the AFB has one of the lowest profiles.

[Dr. Roger]

QUOTE (914GT @ Aug 29 2005, 01:06 PM)

A nice advantage of the Carter AFB/Edelbrock Performer is that you can use a full-size round air cleaner with it and it will still clear the engine lid with no modifications. Other carbs may be OK too but I know the AFB has one of the lowest profiles.

Great suggestions.

I'd go Demon if I had no $ limits... Heck, for that matter i'd go injected if I could afford it.

I just picked up a Edelbrock Performer 750 dbl pumper. $250 at Kragen plus tax.

Real nice tune-ability in the primaries and the secondaries are also tunable. Manual choke so i can use the old heater wire control lever... =-)

Dang it runs well now.!! Perky and responsive. Ordering muffs tonight.... Loud as hell. (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)