3.73's and a 3.06 low gear ,with a four barrel carb, and it doesn't throw you back in the seat? I'd say we need a good tune up here.
For that matter, is the mechanical advance working properly as well? Do you know your initial and total timing? Does the 700R4 have the throttle linkage adjusted properly so the torque converter clutch and part throttle kickdown work like they're supposed to? How much manifold vacuum does it have idling in neutral, and how much at a steady 30-40 MPH cruise?
Ok but there are 2 to three times that with them I just like and have had better luck with Holley Sent from my VS996 using The H.A.M.B. mobile app
A smaller carb will improve low/mid range throttle response due to higher velocity through the carb, but really won't do much for power. I've always liked the 450CFM Holleys on 300" street motors, but they're hard to find these days. And they will limit top-end power, but how important that is depends on how often you go there on the street...
Yes, but the 10 second ones aren't having carburetor problems. Also , it really doesn't have much to do with luck .
Wow somebody loves AFBs I still think they are trash get a Holley This guy is having carb problems with his so get some of your 10 second ones to help him out instead of breaking my balls Sent from my VS996 using The H.A.M.B. mobile app
I stopped putting Edelbrocks on my builds and have gone to Quick Fuel Technologies. They are usually right on right out of the box. Available in the size you need. If it were my 305 it would get a Qjet or a QFT.
I would put a good Quadrajet on it before an Edelbrock. All my cars including stock cars pulled great with a stock-ish factory carb on them. I run a Holley 700 DP on my car, which is a 2.52 1st gear and a 3.89 rear. It has a great pull to it and I'm running a 5/16" fuel line.
The open pipes can cause an out of the box carb to be too lean. You may need to play with the jetting.
For the SBC builds at least, I'll go with the folks recommending Quadrajets. An interesting fact : 390 HP 427 Corvette engines came with 590 CFM Holleys.
Are you using the same carb across all these different engines? If so is the problem consistent from engine to engine? It may just be that carb has a problem...
I never had a problem with a Holley.... Just gotta learn how to "fine tune" those for your application...
...kind of like you need to learn to "fine tune" an Edelbrock for your application. I've had problems with both, and been able to make both types work, too. They're just different, with different sets of problems. I like how the AFB design doesn't have gaskets below the fuel level, so they are not so prone to leaking.
I guess I'm a bit puzzled by how it was determined that the car is suffering from a carburetor problem. Does the carb have an insufficient or delayed accelerator pump shot? Has the float level been checked? Do the power pistons move freely in their bores? Have the metering rods been damaged? The OP seems to be running a used engine with the only changes being to the intake and carburetor. I don't see any indication of how the engine performed in its original configuration. It may be a basically solid engine but with enough miles it wouldn't be surprising if it was getting tired and needed a timing gear set, some valve springs, a good basic tune-up, maybe some cylinder head work and some other basic repairs. In other words, things that swapping a carburetor probably aren't going to fix. Or maybe it is a carb problem. But we'll likely never know, because "...it just seems like it's not rapping out".
Often, a hesitation from a stop sign is caused by adjusting the idle mixture TOO RICH! This can cause puddling in the intake manifold. When the throttle is opened, the additional air velocity in the intake sweeps the puddles from the intake runners into the cylinders, creating a mixture so rich it will not burn. Momentary hesitation, then the engine catches, and goes on about its business. The second most common cause would be a defective vacuum advance or incorrect timing adjustment. The often mis-diagnosed accelerator pump comes in a distant third. Jon.
305's didn't come with AFB's (The hint was "Stock"). But anyway, you being a Holley expert , you could probably list every part # for carb model, jets, squirters, cams, pumps, power valves etc, so our friend could just screw it all together and eliminate any bogging or any other carb issues, right from the get go. Oh, it doesn't work that way? So, like Jim says, all brands can have their own separate issues. They would all have to be addressed , until it acts correctly. The often seen "just get a Holley" is not an answer, per se. I know guys with some very fast cars, that use Q-jets , 600, 750 Holleys, Thermo-Quads, AVS's, WCFBs, 4GCs., even AFBs None of them could be replaced with something else, so they had to be worked on until they were right.
Clay, That's kinda what I was alluding to earlier. It's really hard to dial in a carb until you've got a healthy motor under it.
When you converted to carb you probably should have changed the cam shaft. A sequential 305 is not going to want the same cam profile as a carbureted 305. Nothing wrong with a 305 they can be built and run good and strong. That said the carb conversion is more than a carb and distributer change. @squirrel gave a very good answer by the way read it several time then develop some questions to go along with your build.
You got me I'm only gonna run stock carbs from now on [emoji12] The OP asked about carbs selection THAT IS THE ***LE OF POST, and has said that he has built cars for over 40 years I think he would know if plugs where bad or to check compression and timing on and engine. But without seeing, hearing and driving the vehicle they are all shots in the dark get off your shop box he is not building a stocker Sent from my VS996 using The H.A.M.B. mobile app
If it's a "take out" engine with unknown mileage, I would do a compression check on it first thing. My beloved 283 that was supposed to be 'low miles' had the same problem. It ran normal at the curb but had no power when you hoof it, it had between 35 and 75 lbs of compression across the board. It was just flat worn out.
all of them except for the ones ordered with Holleys through 72. Look up GM part number 3989021, my 71 came stock with it.
To the OP's question, I have 3 OT cars running Holley 4 bbls. All are easy to start, fast and run well until the temp gets over 90 which doesn't happen much in the PNW. I blow an occasional power valve in the Olds but it is simple to replace with gaskets available in any decent auto parts store. Make sure you use a dual plane manifold on that little SBC. It needs the torque. JMHO
Yes, I knew that. I thought we were talking about round port 427's with 585 /600 Holleys, not LT1's with 735/750's. Surprised you didn't mention 68-69 Z28's too.
Sure there's plenty of OEM type carbs that will work for the o/p's application. But seeing he's not building a Stocker, how about a non-stock suggestion? How about a 1050 DP Dominator? Not stock on anything.
I ran a 500 cfm edelbrock(manual choke ) on a lightweight Model A pickup. Stock 283 rebuild, 040 over performer manifold and some headers .Manual trans, Plenty of power for that lightweight truck.
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