Currently running Holley 4175 spread bore on 1975 440 engine. Thinking of switching to Edlebrock AVS2 1406. Mortske on You tube speaks highly of Edlebrock but my mechanic doesn't like them (claims they are bad in cold weather). Thing is the AVS2 is around %500-$ 700 cheaper than the Holley. Why? I've been told "you get what you pay for". Any opinions/ preferences for the Edlebrock over the Holley? Paul
Preference for Edlebrock or Holley?
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Justin Plant
Well-Known Member
Holley is second to none on their add on goodies for adapting the carbs to what ever your application. But, they leak if they sit for too long. All their gaskets are vertical. Edlebrock makes some adaptors, but they are meant to bolt to their intakes. Where Holley's generally mount to the carb. Edlebrocks don't leak and because their gasket is horizontal and at the top of the carb. That said, I have the AVS on my car and other than trying to hook it up to the car it's great.
Eddy carbs work fine in cold weather as long as it and the ignition system are setup correctly. IMO I use Eddy carbs on most of my "street" build engines and a Holley type carb on anything that is going to see track time and I need more tuning ability. I say Holley type because you can get Holly knock offs without paying for the name.
So, you know going from your existing Holley to the Edlebrock means switching intake manifolds or using a cheesy adaptor? The adaptor will require some screwing around with the trans linkage and that's no fun. Changing the manifold isn't the end of the world, but you either have to buy a used one or get an aftermarket manifold.
What's wrong with the existing Holley? They are a simpler carb than the AVS and that's why your mechanic likes them better.
mr gtx
Active Member
so does Uncle Tony. lol
ANY carb can be "bad in cold weather" IF the automatic choke is not adjusted correctly. Plain and simple. I usually tweak mine to suit my driving style and orientation, regardless of the brand.
MY experience with 1980s and later Holleys is that they do NOT leak as the earlier models were known for. BUT . . . I've had more issues on a 4160 with the accel pump diaphram seeping (right onto the top of the intake manifold), though. Easy to fix, though, and they now have better ones for replaceent than they did back then.
The current Holley gaskets now seem to be "glue on" rather than just bare paper of cork as they used to be. Have to pry off the float bowl and the secondary metering plate!
I have an OEM-spec stock replacement 4175 on my '77 Camaro 350 and it has not done anything unusual, period. Throttle response is excellent, off-idle,
I also like the AVS2. My '70 Monaco 383 "N" came with an AVS OEM. I know that carb well. No issues when cold either, but seems to not be quite as throttle responsive ad a similar Holley 4160, though. I like the flexibility of changing the metering rods and such, too. But the accel pump is not nearly as responsive to small throttle movements as any Holley will be.
NOW . . . as to the current Holley carb offerings . . . it seems that ALL of the Holley 4bbls have some "trade name" attached to them. Marketing purposes? Getting an OEM-spec new carb from them seems to be impossible, by observation. Even for the 4160-series. They do have some stock replacement carbs, but they are not what they used to be 10 years ago. They might be more "stock replacement", but that also CAN mean "universal fit" rather than OEM-spec repalcement. To me, this is "not good". BTAIM
I DO like the new venturi design on the AVS2, though. BUT Summit sells one of their "Summit brand Holley 4160-type carbs with them too. This venturi, plus the normal "goodness issues" of the Edelbrock AVS2 puts it favorably on my list.
BUT, rather than one of the "new" Holleys, do not forget about the Holley Street Demon "spreadbore that is not a spreadbore" carburetor. A clone of the Carter TQuad with some changes/upgrades. Even with the phenolic float bowl. Other than any throttle linkage issues (which your 4175 also has), it should be a bolt-on and should also be a closer match to your existing 4175. AND, the pricing should be less intensive, too, I believe (or used to be).
WHAT is the issue with your existing 4175?
CGODY67
MY experience with 1980s and later Holleys is that they do NOT leak as the earlier models were known for. BUT . . . I've had more issues on a 4160 with the accel pump diaphram seeping (right onto the top of the intake manifold), though. Easy to fix, though, and they now have better ones for replaceent than they did back then.
The current Holley gaskets now seem to be "glue on" rather than just bare paper of cork as they used to be. Have to pry off the float bowl and the secondary metering plate!
I have an OEM-spec stock replacement 4175 on my '77 Camaro 350 and it has not done anything unusual, period. Throttle response is excellent, off-idle,
I also like the AVS2. My '70 Monaco 383 "N" came with an AVS OEM. I know that carb well. No issues when cold either, but seems to not be quite as throttle responsive ad a similar Holley 4160, though. I like the flexibility of changing the metering rods and such, too. But the accel pump is not nearly as responsive to small throttle movements as any Holley will be.
NOW . . . as to the current Holley carb offerings . . . it seems that ALL of the Holley 4bbls have some "trade name" attached to them. Marketing purposes? Getting an OEM-spec new carb from them seems to be impossible, by observation. Even for the 4160-series. They do have some stock replacement carbs, but they are not what they used to be 10 years ago. They might be more "stock replacement", but that also CAN mean "universal fit" rather than OEM-spec repalcement. To me, this is "not good". BTAIM
I DO like the new venturi design on the AVS2, though. BUT Summit sells one of their "Summit brand Holley 4160-type carbs with them too. This venturi, plus the normal "goodness issues" of the Edelbrock AVS2 puts it favorably on my list.
BUT, rather than one of the "new" Holleys, do not forget about the Holley Street Demon "spreadbore that is not a spreadbore" carburetor. A clone of the Carter TQuad with some changes/upgrades. Even with the phenolic float bowl. Other than any throttle linkage issues (which your 4175 also has), it should be a bolt-on and should also be a closer match to your existing 4175. AND, the pricing should be less intensive, too, I believe (or used to be).
WHAT is the issue with your existing 4175?
CGODY67
lemondana
Active Member
Carter Thermoquad!
CB; no real issue with the Holley. The reason I was interested in Edlebrock is I was watching Mortske on youtube and he had a 1972 Monte ca
CB ; no real issue with the Holley. I w
CB; no real issue with the Holley. Reason I was interested in Edlebrock is that I was wathing
CB; no real issue with the Holley. The reason I was interested in Edlebrock is that I was watching Mortske on Youtube and he was working on 1972 Monte Carlo. He sat in the drivers seat and without touching the gas pedal he turned the key and the car started instantly (Edlebrock carburetor). With my Holley I have to mash the accelerator 3 times and then it takes 3-4 cranks to start. I'm wondering if the car would start easier with an Edlebrock.
Still don't have an answer about why there is such a price difference ($500 plus) between Holley and Edlebrock. Paul
volksworld
Well-Known Member
the entire situation is only as good as the skill level of your mechanic...in the 80's I had a new 600cfm Holley on a 350 in my tow truck...what I experienced was that even with floats set correctly, over time the fuel level in the secondaries would rise to the point that it would flood, dump fuel and stall...new needles and seats didn't help, I guessed (probably incorrectly) that vibration or hitting bumps bounced the floats just enough to let a little fuel in...never cured it, but the solution was occaisional full throttle runs to use up fuel in the secondary bowl...so, when I put in the big block I decided to go with an Edelbrock Performer cause it used a common bowl for primaries and secondaries...what I found was the Edelbrock ran awful out of the box...now, instead of just using jets like the Holley, the Edelbrock used larger jets with a tapered metering rod suspended inside them...these were spring loaded and vacuum operated so as the tapered rod raised or lowered in the jet it would increase or decrease the amount of fuel that would flow through the jet...so essentially a much more fine tunable carb, if you knew what you were doing...there was a calibration kit you had to buy with different size jets, metering rods with varying tapers and different strength springs to vary how soon the rods moved...I welded a bung for an oxygen sensor into the engine pipe and was trying to tune it by voltage through a multimeter( back before air/fuel digital gauges were a thing)...blew 1st gear out of the trans before I got it right...SO, back to my opening statement...how skilled/patient is your mechanic, how many test drives with different combos is he willing to do or are you willing to pay for to get this thing right...or are we just hoping whatever you slap on runs "close enough" out of the box? if it doesn't ,the Holley will probably require less time to become "close enough" as there are less things to play with...the Holley 750 that's been on my 440 for 25 years has been fine other than a sunk phenolic float about 5 yrs ago and fine since...it never had the issues that I experienced with that 600
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I WILL say that your starting technique is sub-optimal for the carb, period. It should NOT take that many pumps on ANY carb to get it to fire. On all of my cars, I give the accel pedal one little pump, enough to let the fast idle mechanism fully deploy when cold and starting happens quickly. Even on my non-electronic ignition cars.
If the accel pump is doing correctly, that many pumps of fuel is putting about 30cc of raw gas into the plenum chamber of the intake manifold. On a cold engine, it's NOT going to evaporate, so a too-rich mixture PLUS the mostly closed choke plate might well slow things down (as to starting).
How about if you try hitting the starter and then doing a 1/3 pump on the accel pedal and see how quickly it starts from cold? That way, only more-atomized fuel gets into the intake manifold so things should work more normally, to me.
For example, on my '77 Camaro 355 (and the 305 before it), I move the accel pedal enough for the fast idle to do its thing. Start the engine (starts quickly) and then pat the accel pedal again to let the fast idle cam drop off of its highest level. Put the trans in "R" and back out. If the car moves about 1 car length and the engine acts like it's going to die, just one quick pat on the accel pedal brings it back and I back out, put the trans in "D" and proceed 1 block away to the yield sign at the corner and to another stop sign 1 block past that. Then, another 5 block stretch at 25-30mph to another full stop sign. Engine is warmed and is at its normal hot idle speed. Ignition is the stock HEI and OEM coil. Spark plugs are NGK Iridiums (V-powers before that) at about .045" gap. Initial timing is about 8-10*BTDC, just under the ping threshold at WOT. Fuel is super unleaded 93 pump octane, usually Shell or Chevron. Same technique for 32*F as 100*F ambient temps. How'd I get there? Continuous tweaking, one little bit at a time. PM for details.
My other cars are similar, but with not quite as crisp of throttle reponse as the 4175. More crisp that the 9801 TQuad I had on the '67 Newport 383 for a long while, too. Or the used OEM 4160 or the OEM AFB that was original to the car when I bought it.
NOW, I am NOT relying upon some "guru carb tech" to do these things for me, I am doing them myself. Therefore, it is ME against the CARB with nobody in-between. I have learned about carburetors since the middle 1960s and have kept up with them ever since. I learned what to tweak and how to tweak for best results on a stock or slightly "enhanced" motor. From my own experiences and those of my "hot rodder" friends. My tweaks, pondering, researching, tweaking, cycle repeat got me to where I now am. BTAIM
I will NOT say one brand is better than the other, knowing that things HAVE changes over the past 30 years. Venturi design tech has changed a lot, with more efficient designs/shapes, for example. As to Holleys, they have a multitude of pump shooters for a multitude of applications. Smaller orifices for a longer-delivery pump shot as others are more like "flood", in their pump shot delivery amount and duration.
Holleys DID have gasket issues in the later 1960s and later. I heard about this from the Chrysler people, but never heard a word from the similar Chevy people with the same gaskets in their carburetors. The local Chrysler dealer replaced OEM Holleys with a prior-year Carter AFB or AVS in the late 1960s. The Holleys needed a rebuild every year as the Carters were "install and forget". This was not my experience with the Holleys I bought from 1979 forward. Only issue was the (after many miles and the new ethanol'd fuels) accel pump diaphram seeping onto the intake manifold
And THAT MIGHT be all you need on your 4175. A new, ethanol-resistant (or the "blue") accel pump diaphram. Easy enough to change once the primary fuel bowl is drained and removed. A new bowl gasket will be needed. The pump diaphram and gasket are available separately, NOT needing a carb rebuild kit to get them. O'Reillys (locally) or Summit, for example.
As with ANY starting issue, first make sure the ign system if doing all it needs to. Good spark plug gaps, good wires, good dist cap and rotor, etc. Ignitability is key.
Just my experiences,
CBODY67
I do not know the Holley part number. I believe it might be the same as for a normal 4150 or 4160, 4165 (manual secondary spreadbore, as the 4175 is vacuum secondary), or even 2300 2bbl carb. Order by the carburetor series (4175) and that should work fine.
CBODY67
CBODY67
lemondana
Active Member
Mortske is a GM guy. Early on, he didn't know anything about Mopar kickdown linkage and the importance of it. All these You Tubers use Edelbrocks because they can buy them at there local O'Reilly's, then they have to use the adapter. If your Holley 4175 is the Mopar model with the Chrysler throttle linkage and your kickdown linkage is all there, looks right, and functions the way it should-I would stay with your Holley!
$349 difference.
Edelbrock 1406 Edelbrock Performer Carburetors | Summit Racing
Holley 0-80555S Holley 4175 Carburetors | Summit Racing
Have @Dana at Woodruff Carbs rebuild yours if you think you're having issues with it. Carburetor Restoration in Youngstown, OH | Woodruff Carburetor Specialties
lemondana
Active Member
If you are going to buy an Edelbrock, get the AVS2 and not the Performer. Can you post a few pictures of your Holley, so we can see what you have. Take a couple of the driver side-the throttle-kickdown linkages. Them spreadbore Holleys are good carbs. If you have the one with the Chrysler linkage and it's all set up good, just get the carb rebuilt.
Gerald Morris
Senior Member
My Edelbrock 1405 starts up dandy in cold weather. I pull the choke closed a bit, pump once, and WHAM, Gertrude fires right up when I turn the key. I use an old Mopar intake with it, to keep life simple. I admit I suspect my secondary jets might be one size too big, and will get the Edelbrock rods jets and springs kit when I have an extra C note to burn, and will try it on a leaner secondary set. Aside from that, its an extremely simple carb which has served us well for 3 years. For the dollar, I say they're hard to beat.
wyrmrider
Member
Absolutely TQ finding the right number is not hard
JimmyG
Member
I have used Edelbrocks on small and big block Chrysler for eons,...probably 15 different engines and projects. I have yet to see one fail, leak, need maintenance worth mentioning, or be too expensive to run.
Frankly, pick the size you want, drop it on, and away you go. If you want to tune it you can, but I doubt you will need to. I have used them straight out of the box for racing, towing, daily drivers and long distance cruisers. No hassle driving, and rebuildable as well.
Always make sure that you have the throttle adapter attachment for the linkage ready to bolt in prior to your installation.
Frankly, pick the size you want, drop it on, and away you go. If you want to tune it you can, but I doubt you will need to. I have used them straight out of the box for racing, towing, daily drivers and long distance cruisers. No hassle driving, and rebuildable as well.
Always make sure that you have the throttle adapter attachment for the linkage ready to bolt in prior to your installation.
