Rant against Holley 4 bbl vac sec.

Author Topic: Rant against Holley 4 bbl vac sec.  (Read 5659 times)

Offline quagmire

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Re: Rant against Holley 4 bbl vac sec.
« Reply #15 on: May 23, 2010 - 06:13:12 PM »
Haha, I think I'll pass.  If you have tuned these well before and this one is giving you fits that makes me think there is a problem with that carb itself.  Like I said, I'm going to invest time and money into EFI before I go setting up another carb.




Offline DoNotChallengeHer

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Re: Rant against Holley 4 bbl vac sec.
« Reply #16 on: May 23, 2010 - 06:19:04 PM »
Haha, I think I'll pass.  If you have tuned these well before and this one is giving you fits that makes me think there is a problem with that carb itself.  Like I said, I'm going to invest time and money into EFI before I go setting up another carb.
I was kidding. A friend wanted it. I don't know why  :clueless: Neil tried tuning at Carlisle. It was a headache since I got it. I went with a double pumper  :naughty: with manual secondaries . Works great   :burnout:

Offline Chryco Psycho

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Re: Rant against Holley 4 bbl vac sec.
« Reply #17 on: May 23, 2010 - 06:28:56 PM »
I use Eddy carbs as door stops at best
 Holley / Proform carbs for me
I don`t have any door stops around right now to trade you
 Sorry
« Last Edit: May 23, 2010 - 06:45:40 PM by Chryco Psycho »

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Offline quagmire

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Re: Rant against Holley 4 bbl vac sec.
« Reply #18 on: May 23, 2010 - 06:37:00 PM »
Quote
Insert Quote
Quote from: quagmire on Today at 06:13:12 PMHaha, I think I'll pass.  If you have tuned these well before and this one is giving you fits that makes me think there is a problem with that carb itself.  Like I said, I'm going to invest time and money into EFI before I go setting up another carb.

I was kidding. A friend wanted it. I don't know why   Neil tried tuning at Carlisle. It was a headache since I got it. I went with a double pumper   with manual secondaries . Works great   

Lol!  I was actually directing that toward UK, my bad!

Offline 71chally416

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Re: Rant against Holley 4 bbl vac sec.
« Reply #19 on: May 23, 2010 - 06:54:34 PM »
The truth is the companies selling Holley type carbs don't care if 30% have QC problems. It's still more profitable for them to farm them out to China, even if 30% are returned and scraped. That's common knowledge in the machine shop industry that does secondary operations or QC on their crap castings. :grinyes:
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Offline UKcuda

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Re: Rant against Holley 4 bbl vac sec.
« Reply #20 on: May 24, 2010 - 03:25:56 AM »
I don't actually know much about the Eddys except they're based on the AFB - I've never had an Eddy carb.

So maybe the Eddys are not well made -  :dunno:

Also I haven't much experience of the more exotic Holley products - I'm just talking about the standard 4bbl VS.

I don't think there was anything actually wrong with the one I was using, I just didn't want the hassle so I didn't even bother.  The sort of hassle I'm talking about (in no particular order):

1)  you can't change the jets without spilling all the fuel;
2)  you can't change the jets without splitting the gaskets and having to clean up all the remains (unless you have previously been in there and fitted special gaskets);
3)  you can't change the secondary jets because they aren't jets at all, just holes in a plate (unless you fit a secondary jet body but then 1 & 2 above still apply to 2ndaries as well as primaries);
4)  you can't change the power circuit step up (aka power valve) without the same hassles as 1 & 2 above;
5)  although you can adjust the float level from outside, you have to have fuel coming in and it sprays all over as soon as you slacken the lock screw;
6)  adjusting the float level seems to be a good way of damaging the "O" ring seal on the inlet;
7)  changing the secondary opening spring is a proper carry on and risks ripping the diaphragm when the screws go back in and/or not getting a good seal back to the body (I know they do an easy swap one so maybe that's a lot better but why not make them all easy?).

So that's my beef really - once they are set up they mostly seem to stay in tune and go well.  It just seems such a naff way of getting them there.  And when Holley do change things it's usually to use a plastic part in place of a metal one - and they call that progress !?

Anyway, I've now got AFBs on my 360, on my 413 and on my Mustang.

I took the Mustang to the track just after I fitted the AFB and I tried quite a few changes between runs.  If it was a Holley I don't think I would have got half as much track time on it.

Probably the more up market Holley products are easier to get on with, I would hope so.  As I say, this is just my rant against their pesky vac sec foot soldier.
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Offline Chryco Psycho

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Re: Rant against Holley 4 bbl vac sec.
« Reply #21 on: May 24, 2010 - 09:44:32 AM »
nothing is perfect especially when the desin is over 50 years old & no more technology is being developed for the carbs by the big 3 or big 12 auto makers , if you want a good design get EFI for the entry price of $5000+ , no spilled fuel & tuning with a laptop
 now having said that there is far more tuning capability in a $500 Holley carb then an out dated Eddy AVS or AFB carb , the powr valve offers 10 choices , eddy 5 , jetting is unlimited & Is not combined with metering rods allowing far more accuracy , rear jat changes are easy as long as you have a dual metering block carb ,most new Holleys have a removable port to swap secondary springs Eddy Has 3 squirters holley has 12or mor , Eddy has 3 positions for the pump cam holley has 8 cam with 2 position each , most new Holleys & Proforms have swappable bleeds for dialing in idle circuit & jetting circuit , eddy has no provision to do this unless you epoxy the holes & drill them back out , HP holley have 4 corner idle , Eddy has never had this , except that it has a cross over port to allow fuel into both left or right barrels adjusted by 1 screw , you cannot adjust float level on a Eddy if you pump put out higher or lower pressure but at least the holey can be set running ..... so yeah you have to splill some fuel to set them up but they are far more accurate when tuned

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Offline UKcuda

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Re: Rant against Holley 4 bbl vac sec.
« Reply #22 on: May 24, 2010 - 02:57:51 PM »
It's a fair cop.

And you forgot to mention - the AFB secondary opening point/rate can not be adjusted (except by drilling the counter weights) whereas the Holley has five or six different springs for it.

But I think the AFB does also have almost unlimited mixture adjustment in the primary jet/needle combos.  It's not limited to what they show on the tuning chart - you can work out your own combos with a bit of circle geometry.

I would also say that the power circuit air/fuel mixture on the primaries seems more tunable on the AFB than on the Holley.  But overall you are right; the Holley has a lot more variables on more aspects.
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Offline djwhog

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Re: Rant against Holley 4 bbl vac sec.
« Reply #23 on: May 24, 2010 - 05:04:33 PM »
Only the high end DF DPers are more tune optioned with dual blocks.

ou can gt an AVS style aft and have dual fuel inlets, adjust sec timing etc view a screw, and accel pumps, larger seats, squirters, jets, rods, accel cams etc are all changeable. You can do a lot with these carbs too.


Offline UKcuda

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Re: Rant against Holley 4 bbl vac sec.
« Reply #24 on: May 24, 2010 - 05:43:24 PM »
I had an AVS on something years ago - I can remember trying different settings on the secondary air valve spring screw, but I totally can not remember what the car was or what it ran like - LOL

Anyway, I'm loving my 360 with this 625 AFB.  If anything it's a bit too lively as a daily - I nearly rear-ended someone today when I kicked down to overtake and it set off like a scalded cat.
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Offline 71chally416

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Re: Rant against Holley 4 bbl vac sec.
« Reply #25 on: May 24, 2010 - 06:40:33 PM »
The new Thunder AVS's are WORLDS better than the originals. For one they have boosters for the secondaries instead of those old drip tubes and for another they are have much more airflow than the old originals. I'd even bet they can come within 5 hp of a 850 Holley Dp on the dyno on a healthy 440, because I've already seen it with the lesser EPS800. The difference is less ring wash down than any DP carb on the street and all the things mentioned by UKCuda. #5 has always been my favorite. Nothing like gas spraying everywhere with the motor running.   :pullinghair:

And Dominators are not exempt from bad castings. One of them from the old race motor that I sent to Patrick at ProSystems had a major flaw. He phoned and asked if we had any problem with it, and it never did run quite right before he fixed it.

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Offline Changin Gears

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Re: Rant against Holley 4 bbl vac sec.
« Reply #26 on: May 24, 2010 - 06:56:49 PM »
The problem I have with any of the Carter derivatives and the Holley’s with a metering plate (including factory 6-paks) is that when the secondary’s are open, they are by design in full fuel enrichment mode, regardless of vacuum level.  They have no power valve or metering rods on the secondary’s. 

Seems like fuel economy was of little concern when these were designed.


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Offline 71chally416

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Re: Rant against Holley 4 bbl vac sec.
« Reply #27 on: May 24, 2010 - 07:06:16 PM »
Gas was cheap in the 60's  :grinyes:
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Offline djwhog

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Re: Rant against Holley 4 bbl vac sec.
« Reply #28 on: May 24, 2010 - 07:45:27 PM »
The problem I have with any of the Carter derivatives and the Holley’s with a metering plate (including factory 6-paks) is that when the secondary’s are open, they are by design in full fuel enrichment mode, regardless of vacuum level.  They have no power valve or metering rods on the secondary’s. 

Seems like fuel economy was of little concern when these were designed.

True, but I used to shove an air full probe in the exh, and since this does not effect MPG, I mean if you have to have 75% open throttle before they open you are not looking at MPG right?

So you can jet as needed on the sec side to make sure it is not to rich or lean and makes the power you are looking for depending on the application, street/ mild strip etc.

They worked very well on the 2x4 Hemis back in the day for a street car.

When more HP is needed I too would go with a Holley or a Speed Demon unit.

All great points guys! :)
good thread!

Offline dodge freak 2

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Re: Rant against Holley 4 bbl vac sec.
« Reply #29 on: May 24, 2010 - 10:21:16 PM »
You know what is even better than using one Carter carb? Using two of them :smokin:

I was a Holley / Demon guy for 20 years and yes they can be a hassle to tune..once tuned they are pretty darn good and no single Carter will outperform most any dp Holley.

However two Carters can put up a very good fight against one holley carb, lol.

I found the Carters give a better idle and better throttle response. Might be weak on the power end but only drawback and just use two Carters to make up for it, ha ha