iskwezm
10 Year Member
Carb advice please
- Thread starter gonzothegreat
- Start date
brianj5600
Active Member
The 650 you already have is were I would start. If it has billet blocks, it might have adjustable PVCR's. I bet it has screw in air bleeds, and probably nitrophyl floats. I hear blower blow throughs are much easier to make work than turbos.
Edster
Founding Member
Well, like I said earlier, you can't really compare any hardcore racing carbs or parts to edelbrock carbs because they just don't make any racing carbs, they are all street carbs. If they did make a strictly racing one, I would put it on my racer hands down.
Why are you getting so defensive and telling me I don't know anything about carbs? The reason you see a ton of threads floating around here with secondary lean hesitations that "can't be tuned out" is easy. I'll use your argument here. "If they knew what they were doing, it wouldn't be a problem." I have no problem getting any secondary hesitation out of my edelbrocks. Why do you see a ton of threads floating around here asking about holley power valves? And why do I have to constantly change my idle mixture screws? Do I need jet extensions? Where is this massive internal leak coming from? Edelbrocks have far fewer types of problems because they are more simple, so they always have the same problem.... hesitation. The reason holleys don't have that more is because the vacuum secondary carbs open more slowly, and the double pumpers are shooting in twice the gas. Kudos to that, but it's not really a problem for me and my edelbrock. I see threads with part throttle richness or lean conditions that they can't get rid of on holleys, no problem to fix with an edelbrock's metering rod system.
Even Vic himself runs Holleys on his race cars.
One of the guys on Stangnet caught him at the track a couple of years ago with a holley on one of his track cars.
Hahahaha, who is Vic? Sounds like he owns Edelbrock. That's ironic
Exactly right. But E carbs have fundamentaly flaws that you may be able to cover it up, but it's still not tuned properly. Just because it doesn't bog or hestitate doesn't make it right.
THat's because you have to make the pump shot up front so huge, it covers the lean spot. Or put light springs in metering rods to activate it earlier. Or raise the float levels. You you do enough of it, you can get rid of the bog. But if you cover up the lean spot with a primary squiter, I would had to see your in town mileage when it's not needed
Please refer to the first quote. People would rather ask questions than learn by reading or experimentation. Then they get answers on here from people that don't know any better either. then they blame the holley because they can't tune it when they used bum advice to begin with.
The idle mixtures screws should never change once tuned proerly, no matter the car. the motor only needs what it needs to run. If it changes, it's not going to be the carbs fault.
If you can create over a G out of the hole or about 1.7 60 foots, yes. Easy answer. But I've never seen a car with an E carb pull the wheels, so it might not be a problem. I dunno. Never seen it happen yet.
These are the best ones. People go to swap meets and buy "junk' holleys and rebuild them and sell a perfectly good working carb. I remember the first time I got pissed at a junk hooley. I the needle and seats way to high and the motor would barely run. OR they get a great deal at a swap meet, throw in a kit with no idea how the reset the floats. And it runs horrible, and that's if the poor thing gets a rebuild.
The are simpler, but that is the reason you can't dial them in as well. It's no more difficult than E carbs to get them close to perfect.
Holleys are adjustable. e's aren't. If you get a holley that bogs, you slow it down until the bog goes away. Can't do that with an E. Your stuck with how ever fast it opens and that's it.
The only thing better about an E is that it is easier to make changes to cruise VS WOT because the rods are easy to change. But the combinations are very limited. I would rather it be more difficult honestly, for a more precise tune.
I'm not defensive about any of it. Nor do I care if anyone uses them, or insult them if they use them. It's less of a mess to tune, that's about it. Just don't call them better or hard to beat. THey really aren't all that and a bag of chips.
well, a lot of the stuff you said about the tuning of them, especially overcompensating with the accelerator pump and having bad gas mileage just isn't true. I would get 15 mpg in town and 27 on the freeway with a 750 edelbrock and never could get any better than 13 in town and 24 on the freeway with the stock carb and similar with a double pumper. I guess there is no point arguing though, people have shown their liking for one carb or the other for a long time.
But have you not heard of the thunder series edelbrock carbs? Secondaries are adjustable. Plus, on other models, people have been adding weight on to the air valve flap weights, or filing material off to adjust how fast or slow the thing opens for years. People have been scratching their heads at how fast my car goes with an edelbrock and how good the mileage is, considering. They can't be all that bad.
But have you not heard of the thunder series edelbrock carbs? Secondaries are adjustable. Plus, on other models, people have been adding weight on to the air valve flap weights, or filing material off to adjust how fast or slow the thing opens for years. People have been scratching their heads at how fast my car goes with an edelbrock and how good the mileage is, considering. They can't be all that bad.
Since this is fast turning into an Edelbrock vs. Holley thread...might as well throw in my $0.02. Had two Holleys on my Dad's Mach 1 - the first and the last. I never really listened to the talk on Holleys losing their tune often - after all, how many things are there in a carb that can adjust themselves? - but after seeing a dyno tune's benefits disappear in less than two weeks, I'm not too hot on Holleys. Had an Edelbrock on my own '68 for three years, never had a lick of trouble. Throttle response was average, but gas mileage was pretty good. The Carter I have on my car, which is pretty similar to today's Edelbrocks, oddly enough seems to possess awesome, lightning-fast throttle response with really bad gas mileage. Still reliable though. Both retained out-of-the box settings, FWIW.
However, Holleys are capable of more power out of the box and are more tunable, no doubt. If you want the ultimate in speed and can/are willing to take the time to keep it tuned, Holleys will reward you every time with better power, hands down, guaranteed. If you want reliability...look elsewhere.
However, Holleys are capable of more power out of the box and are more tunable, no doubt. If you want the ultimate in speed and can/are willing to take the time to keep it tuned, Holleys will reward you every time with better power, hands down, guaranteed. If you want reliability...look elsewhere.
Did you know taht double pumpers are jetted for race cars ? And the PVCR's are little on the small side because the fronts are jetted up5 sizes. Not crucial in a race car. A vacuum sec holley even gets better gas mileage than a DP.
Sure, and it only took them what 40 years to finally make the secondaries adjustable ? But nobody yet, really even has those carbs. And you still have all the other flaws of an E carb.
the fact that it took 40 years to come out with adjustable secondaries maybe means there was never really any problem with it in the first place?
At least nothing to complain about? I dunno, that logic could be thrown in there. I'm not going to argue with you anymore though man, waste of time. All I know is I have much better results with edelbrocks. I laugh at people that throw on an edlebrock, it has problems because it is usually running lean, and say it sucks and throw on a holley that runs too rich out of the box but appears to work fine and they call it good. Yeah holley is a lot better than edelbrock
Never had a problem with a vacum secondary opening problem that could not be tuned out with the Holley spring kit. I have had 2 Carter AFB's (Edelbrock)that cracked throttle bodies and would leak-down after shut-off and foul plugs like crazy.
The secondarys open in such a way that, assuming you have the correct spring in place, you will not feel any surge upon opening, only a smooth, strong pull up to the point of power trail-off or valve-float.
The way we chose power valves was to subtract 5 from your vacum-at-idle reading and round-off to the Holley size (ex. vacum=12...subtract 5=7...choose a 6.5 power valve). End of problem.
All of the above is assuming you have a good engine with proper vacum signals...seeing as most carb troubles are really engine troubles.
I am curious what you mean by cracked throttle bodies and how exactly they cracked.
Most leak-down after shut-off problems with edelbrocks are excessive fuel pressure problems.
They both cracked under the throttle plate. One on the passenger side rear and the other on the driver side rear. Two different manifolds two different cars. Tom (master mechanic certified in all phases of auto and heavy trucks) found the 1st one and said it happened a lot and that most guys who had this problem would end-up changing the carb thereby fixing the problem but they never knew exactly what the root cause was. Tom is one of the very best wrenches I've ever known and I take him at his word. Not something I do very often.
That said, my best friend is the 2nd owner of a 1966 335 hp GTO with the original AFB and his brother has what I consider to be the best 32 Roadster in the world (it was the black one at Charlotte Auto-Fair last April) with an Edelbrock and neither one has had ANY troubles with them. I've just had much better luck with Holleys and zero luck with AFB's.
The 780 that came on my BOSS never gave a problem. It just was not big enough for those over sized heads.
To address leak-downs....don't know about AFB's but a Holley will leak-down if the air bleeds in front of the booster venturis are clogged. Sometimes you stand there and watch the fuel siphon from the booster venturi.
