akitagandy
Member
I have a SBC 350 ,030 over ,flat top pistons ,small cam. What kind of carb would be best (Holley,edelbrock,600,650,700,double pump,etc
Carb cfm
- Thread starter akitagandy
- Start date
EX JUNK
Moderator
An Edelbrock 600 would be my choice as that is what I used on my '37 with the same engine that you described. It has performed excellently from the original start up with no adjustments.
Jim
Mike
Well-Known Member
I think when we start wondering who makes a better carb, we're this >< close to asking how long a piece of string is.
For a street-driver and assuming the car is not geared out of this world, a double-pumper is always going to be harder to tune. I always recommend staying away from them, because there is just no need to go to the expense for something running at low RPM.
A 350" motor that will likely never see the far side of 6,000 RPM would want to use a 600 CFM carb. Assuming 100% volumetric efficiency. Most extremely mild street motors would be pushing the envelope to operate at 80% VE, so that 600 CFM suddenly becomes 480 CFM. But remember, remember, remember, that is at 6,000 RPM.
The wee carbs can often carry a dear price tag, so I'm with Jim on this one. Only I'm more familiar with Holley carbs, so I'm opting for a 600 CFM vacuum secondary Holley, with an electric choke. You'll spend most of your driving time on the primary side of the carb alone, so that will ensure really good throttle response and when the engine requires more air/fuel flow, the secondaries will open. You almost get to have your cake and eat it, too.
For a street-driver and assuming the car is not geared out of this world, a double-pumper is always going to be harder to tune. I always recommend staying away from them, because there is just no need to go to the expense for something running at low RPM.
A 350" motor that will likely never see the far side of 6,000 RPM would want to use a 600 CFM carb. Assuming 100% volumetric efficiency. Most extremely mild street motors would be pushing the envelope to operate at 80% VE, so that 600 CFM suddenly becomes 480 CFM. But remember, remember, remember, that is at 6,000 RPM.
The wee carbs can often carry a dear price tag, so I'm with Jim on this one. Only I'm more familiar with Holley carbs, so I'm opting for a 600 CFM vacuum secondary Holley, with an electric choke. You'll spend most of your driving time on the primary side of the carb alone, so that will ensure really good throttle response and when the engine requires more air/fuel flow, the secondaries will open. You almost get to have your cake and eat it, too.
Screaming Metal
Active Member
What he said X 2! :gum:
ellis8500
Member
For a street machine with mild to mid-range cam, a 600 CFM vacuum secondary carb is the right choice. If you ever decide to go to a more aggressive cam, you've still got the right carb for the 350. With vacuum secondaries they will only open when you need them so most of the time you'll just be running on the primaries and, you can adjust the opening point for your engine setup. Holleys are highly rated by the Cobra replica crowd, Edelbrocks not so much. Take a look at the Summit Racing line of carbs. They have a one piece, leak free body like the Edlebrocks but use the Holley guts. They have bowl sight glasses and external fuel level adjustments. Looks like they took the best features of several brands and rolled them into one design. Also, lower cost then either Edel or Holley. Just a suggestion.
**** In the spirit of disclosure, I do not work for Summit nor do I have any financial interest in the company. ****
**** In the spirit of disclosure, I do not work for Summit nor do I have any financial interest in the company. ****
deckofficer
Banned
Wow, everyone is in agreement on this one! I wonder if it has anything to do with Mike chimeing in early? I ask because when you attend "T only" events, you will see (and sometimes smell) over carburation in spades. I also agree with Mike that if it wasn't for the higher cost, a 490 cfm would work sweet, more than likely better off idle response due to higher velocities at idle. As for vacuum operated secondaries, I'm a firm believer that my engine, via vacuum signal and throttle position, knows better than my dumb right foot when it can use more fuel.
Bob
Bob
sschutze
Member
I had a SBC 350 engine, bored .030" over with an RV cam in my El Camino, the Edelbrock 600 worked like a dream.
Screaming Metal
Active Member
Like Mike said in a few of his earlier writings, its all about V.E.! Ideal would probably between 420 and 500....but the 600 is hard to beat. If I recall, I think there is a Carter 515 or a 525....
Your right, the 390 and 450 holleys are expensive new. Hey now, we all like it when Mike starts on all that sexy, techno talk! Its enough to make a Engineer blush! Haha!
Your right, the 390 and 450 holleys are expensive new. Hey now, we all like it when Mike starts on all that sexy, techno talk! Its enough to make a Engineer blush! Haha!
Differen T
Member
There has been some very good advise given here. Back in the day the basic rule for high performance engines was 2 CFM to 1 CU IN. For the street stay below this figure. For street vehicles with basically stock automatic transmissions and stick shifts with high gearing use vacuum secondaries. Higher weight to power ratios use vacuum secondaries. Better driveability use vacuum secondaries.
It seems that quite a few people have a preference for Edelbrock carbs, I guess I'm old school as I prefer Holly carbs. I like the lack of moving parts (less to wear) and not as many little parts (easier to rebuild). Speaking of rebuilding, a good cleaning and new gaskets and you are ready to go. I prefer the models with center hung float bowls and secondary metering blocks with removable jets. They make for easier adjustments and less chance of fuel leaks. It is also my understanding that the newer models have cured Holley's big weakness by eliminating blown power valves.
Now we come to the tough part, what do you want the top of your mill to look like? In my mind nothing says performance like an air gap high rise manifold, a Holley dual feed carb and an air filter that says the business starts here. I like Edelbrock manifolds and their new Performer air gap (idle to 5500 RPM) fits the bill.
Al
It seems that quite a few people have a preference for Edelbrock carbs, I guess I'm old school as I prefer Holly carbs. I like the lack of moving parts (less to wear) and not as many little parts (easier to rebuild). Speaking of rebuilding, a good cleaning and new gaskets and you are ready to go. I prefer the models with center hung float bowls and secondary metering blocks with removable jets. They make for easier adjustments and less chance of fuel leaks. It is also my understanding that the newer models have cured Holley's big weakness by eliminating blown power valves.
Now we come to the tough part, what do you want the top of your mill to look like? In my mind nothing says performance like an air gap high rise manifold, a Holley dual feed carb and an air filter that says the business starts here. I like Edelbrock manifolds and their new Performer air gap (idle to 5500 RPM) fits the bill.
Al
Mike
Well-Known Member
I think some of Holley's bad rep from years gone by is still sticking a fork in them.
People got sick of the fuel leaks on Holleys, but the gasket technology has improved so much over the last 15-20 years that the leaks are pretty much a thing of the past.
And for the fellows that just can't be bothered to properly set valve lash, ignition timing and choke blade settings, the old Holleys had a real issue with the power valve being vulnerable in a backfire. (I'd love to have a nickel for every time someone has told me a Holley would make their engine backfire. :winkn
Since Holley finally got onto our old trick of putting a check ball in the power valve vacuum passage, that problem is nearly a thing of the past.The Edelbrock carb, which is a Carter by any other name, is a good enough carb. Simple and basic. When it comes to working on carbs, my Holley to Carter/Edlebrock ratio is probably in the 250:1 range and I'm just more familiar with the Holleys.
I also admit to not having much business respect for Vic Edelbrock. When it came down to manufacturers turning the high performance industry upside down with ridiculous pricing practices, Vic Edelbrock was, in my not-so-humble opinion, the biggest whore on the block. But when it comes down to it, I will agree that his Performer series intakes work very well. And in a lot of applications, to boot. Back when everyone was pulling race car trailers with 454 dualies, we had a 272° cam/Edelbrock Performer 2-O intake/0-3310 Holley carb combination that worked a treat. I would hook a customer up with that combination and within a couple weeks, 3 or 4 of his buddies would be calling to get the same deal. The combination made a ton of torque and improved fuel mileage by about 25%.
<sarcasm> But gee, why would we ever want to make a pile of torque in a street rod? </sarcasm> :dunno:
2old2fast
Active Member
Yawn ...600 this, dual plane low rise that ,270* cams .... vanilla this vanilla, that boring boring aren't these supposed to be hot rod's yaknow, overcammed gas guzzling snorting, rough idling hot rods? cheez,somebody's gettin old. .........Just put an efi 4 banger in it and see if you can fit your barcolounger so you'll be comfy.. end of rant.. dave :flush:
sschutze
Member
Sorry Dave, you're right. I don't know what came over me. :shrug:
If it makes you feel any better I had my El Camino tuned for power so it only got 8 mpg.
Mike
Well-Known Member
There's the community spirit we've all come to love and enjoy around here.
As for the comment about getting old, I'll plead guilty to the charge. If I need a 'rough idling hot rod' to convince anyone of my virility, I'll pull a vacuum cap off the carb. Other than that, I'm looking to build something I can enjoy driving.
2old2fast
Active Member
as steve martin would say, "well, excuuuuuuuse me". no seriously, this is what my recollections of hotrod's from 45 years ago are, just trying to relive a little of the past. and yeah, I do enjoy it, the sounds , the, smells, the "look" the "go'you know what I'm sayin' and by the way, I'm 62
dave
dave
old round fart
Well-Known Member
Gas guzzlin' was not a problem "back in the day" when gas was .39 cents!. I can enjoy the car a lot more if I don't need a back adjustment after a short cruse and if I don't need to put the money in the gas tank I can drive more and still buy chrome!
Gerry
Well-Known Member
Agreed. I would rather put $1000.00 of fuel in my car than pay $50.00 for a PS3 game. Its good to live in reality instead of an ethereal world
Gerry
Hot Rod Todd
Member
Some people are either dumb or stubborn. :hooray:
Im not too sure which I am,(probably both if the truth be known) but I can assure you that a pair of 1095 Dominators on a street bucket that hates pumpgas takes the fun out of cruising my bucket.
Some nights, I lie in bed & think about building a simple 27 roadster with a twin turbo EFI 5.4 quad cam Ford V8 (Australian stroked version of your 4.6 quad cam engine) that I can drive 1000 miles without any grief.
The only problem with the 600 carb/dual plane manifold option is that it doesnt look racey enough.
here ya go Todd. have your cake and eat it to :jester:
Not my style, I think if it looks impractical it really should be, but.................... injection look without the injection
Russ
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