Is it any better? Edelbrock 500cfm AVS to 650cfm AVS2 carb swap.
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- เผยแพร่เมื่อ 7 ก.ย. 2024
- Fixing what wasn't broke I swapped my old Edelbrock 500cfm AVS to a 650CFM AVS2. The Edelbrock AVS2 Series features annular flow primary boosters with a new calibration for improved off idle and cruising and better fuel economy. Glad I did. Idles and runs better already. Still need to tune out the off idle lean spot but I had to do the same on the 500. Adjusting the accelerator pump and a stronger step-up spring should do the trick. 5.7/350 SBC with Vortec heads and electric fuel pump.
I appreciate the NB reference during the cut away. It gave me a chuckle. Thank you!
After getting tired of the Rochester and Holley, both of which were complicated to keep their settings, I opted in my Corvette 1980 for this Edelbrock carburetor model, and I don't know if it's the best-performing one, but it's practically just as fast with a smooth, even ride, and it always maintains its tuning. It's excellent
Its ok, I am always fixing things that's not broke. 😊
I replaced my Holley with an AVS2 of equal CFM ratings and the Edelbrock seems to have solved all the issues I was having with the Holley. All I needed to do was adjust the idle mixture & speed, the choke, and It runs nicely with full manifold vacuum vs ported vac. Ford 357 W, with low compression truck engine, '73 Ranchero....
....RooDog....
Most of the time, the lean spot was not enough accelerator pump squirt. However, many years ago, when the octane started to drop we noticed more of this stumble occurring, on different vehicles. We raised the octane of the gasoline, and it solved it. I would give this try. If this were to solve it, I don't know what you would do as adding higher octane gasoline is not cheap and can be inconvenient. As you said, you have pretty much tried everything and going as rich as you said you have done, creates other problems. I had an AVS on my 1969 Dart and it had very good throttle response, compared to mother carburetors I tried on it.
Good vid, Les! I'm currently rehab-ing an abandoned 400SB.....That 650 oughtta be perfect for it too! LOVE yer C-10, brother!!! Great video!
C10 in the park. Waxahachie always a good time! Working on my edlebrock right now.
Love the AVS2 650 on my 68 plymouth sport fury HP 383. Awesome carb...engine has great response, idles great, etc.
I started all my carb problems due to ethanol in fuel several years ago . I replaced lines with ethanol resistant and I run Lucas ethanol neutralizer in everything and haven't had a single issue since.
Just get non ethanol fuel.
I have the same AVS2 on my Plymouth Fury 5.9L 360. I like it.
Been a fan of Edelbrock for decades. Easy to take apart and tinker with. I was always taking the top of my carb off and playing with it. Then it dawned on me... I was always playing with it. It never really ran all that good. I was finally talking into doing one more swap. Installed a simple Holly. Wow, no problems at all. I have no idea how hard it is to tune a Holly, never needed to!
Thanks for info . I was looking at a larger AVS2 for my 460 Ford jet boat. Yep I heard that lazy spot as well. Might need kick down adjustment. That is great vacuum
Kudos to you sir most people put way too big a carb on their car
If I heard you correctly I'm a ways west of you in Alvarado Texas
Good stuff bud nice truck 😊
I love the Edelbrock carburetors! they are very close right out of the box once you get them tuned they will never lose a tune by the way I knew you were from Texas when I saw the sticker on your windshield lol hello from Waco!
good looking chevy all u need is a good cam
I like when he said he was going to give it all she’s got 😊he wasn’t playing …
I've always liked holleys better, but I've been having some trouble with one now and I think I'm about to try one of these, people keep raving about the AVS2. Also I've seen evidence on dyno charts/runs on youtube that the whole "too big a carb" thing is kind of a myth, well, at least with vacuum secondaries. With mechanical it may bog
BTW. Vacuum is measured in "inches of mercury" not pounds.
Great video, and glad you don't use useless background Muzak as many TH-camr poster do.
Keep up the good work....
Thanks, you are totally right. I caught that too when editing. I think I need to go back to school with some of the words used and my pronunciation when I go back and see and hear myself. Yikes.
We use " of water at work but, we aren't automotive. We design and Build Industrial Fired Heaters, Waste Heat Hecovery Units, & Heat Recovery Steam Generators. I converted horsepower to BTU/HR the other day cause I was curious a stockish 350 is around 1,630,000ish BTU/HR 😆
@@Wbroach24 One can use inches of water, but the raw numbers will be different, like inches vs milimeters, or Fs vs Cs....
A. Like your calm approach. B. REALLY frustrated that you didn't show the results of your tuning to the 650. Grr. I did give you a "like".
Maybe I should do a part two in the future.
Awesome videos
Unless I’m wrong about the filter logistics, a taller K&N would leave a gap on the lower part of the filter but would still be mostly stock looking. OR modify the air cleaner with a second snorkel if it will fit in the bay. Either would look ok and function better.
Your secondaries opened too soon, you need to tighten the flap to let them open later, and your transmission is shifting too soon. I would also put a air cleaner on there with a flat base or elevated base so the air flows downhill into the carb, Edelbrocks like that vs a regular air cleaner, also a top for the air cleaner that is a filter rather than solid, they really do help.
Thank you. I will look into that and try that it out.
@@turnertruckandtractor There is a spring that is tightened on the air valve over the secondaries as Jeff above posted. You should be able to find a TH-cam video on this adjustment.
You know what I noticed about the old original edelbrock carbs, the secondaries begine to open at 1/4 throttle. I was having a way too rich problem, noticed that and so I just disconnected the secondaries all together so I can have "economy mode" with how these gas prices are.
Nice truck
Thank you.
Have a 1906bp that i plan on pairing with my 355sbc should make my 57 gmc happy
The first thing you need to do is get rid of that single snorkel air cleaner. It is extremely restrictive, to the tune of 10-20 hp. Watch the episode of Motor Trend Engine Masters where they compare different filters. As I recall on their high horsepower dyno engine your air cleaner assembly cost almost 100 hp.
Thanks for watching and the observation. I agree with you and have seen that video. It is a good one. The bottom of the air cleaner housing has been swiss cheesed with speed holes for that very reason. Plus I like the throaty sound of the carb to be heard when you floor it.
Absolutely right. I viewed same episode of Engine Masters
Have you fixed the stumble?
Great video thanks for the info
12-9-2022 it sound like your distributor setting might be a little bit off ( or ) your carburetor choke is too far open should be about the thickness of a ink pen or pencil open. * Check the carburetor choke first.*
So on the accelerator pump the rod I believe is in the centre hole of the three,so which hole did you change it too ?
I guess it would be the bottom hole to make it a quicker squirt ?
Great video 👍
Thanks. It comes with the pump rod on the center hole. I moved it to the top hole so that it has longer travel thus a larger squirt.
@@turnertruckandtractor Many thanks for your reply here in the UK
Part 2…?
Uncle Tony says the Edelbrock cfm ratings are not exact. They are actually much lower than advertised. Is this true?
I've seen tony's video you mentioned. My personal experience supports that idea. When I bought the 500 cfm I thought it was support my 350 at sub 4000 RPM but the 650 definitely made it run better even at low RPMs. I'm pleased with it and not changing anything any time soon.
Good video, im working on my 67 C10 and will probably be using the same Edelbrock carb when I get to that point. Did you have to buy and adapter for your original air breather to fit correctly on the edelbrock carb? Thanks.
It is an aftermarket air cleaner with a 5-1/8” opening. I did have to get a 1” spacer to lift it up to clear the linkage and distributor.
Great vid!
How did the MPG compare between the 2 carbs?
Good question. No noticeable difference. Granted it only gets driven under a thousand miles a year.
THEORY
cubic inch displacement multiplied by maximum r.p.m. then divided by
3456 will give you the proper size carburetor for your engine.
How interesting!
I just did this for my 318. Your method showed 460!
I’m currently running a nicely tuned edelbrock 500 AVS which runs perfectly. But I have often wondered if I would gain anything by jumping up to a 650?
I’ve also heard of the other method whereby you multiply your engine size by 2 so in my case it’s nearly a 650.
Hmmmm. Dunno.
Is it worth it?
Over here in Australia a new edelbrock is approximately $800 then of course tuning which could be as much as $500. Gets expensive quick. It would suck to do this and have no gains,just an empty pocket.
@@Tk-ou9ec Just saw your comment, I have a 318 and I wonder if it would be better low end torque with an avs2 500 cfm than the 650avs2. Like you I don't really want to spend a bunch of money on a test. A lot of used 650's around here but 500's very rare. I currently use a thermoquad for its small primaries, quite smaller than the 650 edelbrock.
I wonder how the AVS2 500cfm would feel versus the 650 AVS2 as the improved feel you have might be based on the new design rather than cfm size.
Very true. I changed two variables to your point. Just did 300 miles in it last Saturday and it did great.
@@turnertruckandtractor I am thinking of going from a 600cfm non AVS2 to a 500cfm AVS2, so the opposite to what you have done, not sure now which way to go 🤣
@@RamblingClassics if your engine is under 350 cu in and under 5000 rpm’s I would lean towards the 500 AVS2.
@@turnertruckandtractor it is a 327ci so yes I think the 500cfm AVS2 will fit very well so will probably go in that direction. I Very much enjoyed your video and now follow up chat, thank you 👍
@RamblingClassics I just bought the 500cfm avs2 for my 95 mustang gt carb swap project. I'm hoping I didn't go too small. The math says 500 cfm will be plenty.
great video. so, were you able to tune out the lean stumble, and would you say it was worth it to go to the 650?
Totally so. Just got back from a 500 mile round trip with it. I was able to tune it out by moving the accelerator pump lever hole, tightening the AVS spring a 1/4 turn counter clockwise and using the silver 8# springs.
@@turnertruckandtractor awesome- so worth it performance wise to step
Up to the 650 now that you got it sorted out?
@@kevinclancy. yes. I thought the 500 as fine and had no complaints. The 650 has been all around better. 350 ci late model SBC all stock except for thin head gaskets and 1.52 roller rockers.
@@turnertruckandtractor thank you
What type of mechanical fuel pump you are running
It is a late model SBC block without the mechanical fuel pump. I am using an electric fuel pump located on the frame under the stock tank behind the seat. Make sure your fuel pressure is between 3-6 psi.
What electric fuel pump setup are you using? Trying to get some ideas for fuel pump . I am also putting a stock vortec 5.7 engine with a 650 avs2 in my 57 chevy. Thanks for your videos
I have a feeling you won't need the tune up kit.
Edelbrock dont have the emususion circuits that others (like holley) have. The fuel is less atomized. I know from experience, i have made many custom metering rods, jets, air bleed mods, air valve mods to Edelbrock carbs over the years. Fact: you wont find an Edelbrock on a racer car in todays racing outside nastalga.
Fact: edebrock is a good carb, thats easy for the backyard mechanic to setup.
Fact: they are all too rich righ out of the box.
Agree with everything here with the small exception of all too rich but most are. Guess Edelbrock likes to error on the rich side since it is a little less evident or troublesome. Edelbrocks commonly have a lean spot off idle out of the box I have found.
That air cleaner is a huge restriction as far as performance. Completely Counterproductive in fact
Thank you. Can't see it in the video and I did not mention it but the bottom side of the housing has holes all around it for that reason. I also have an open air cleaner for it and detect no performance difference between the two.
Would you say it was worth the investment of getting the different carburetor or not?
Yes I can it was. Both were good but the 650 has more power. Should have gone that route originally but on the carb sizing calculators thought the 500 would be perfect for my application and provide best low speed throttle response but the 650 has been better.
@@turnertruckandtractor excellent, thank you for the video and your response, I found one on Facebook I will be purchasing for my sbc!
@turnertruckandtractor great video! I'm about to do a sbc build and had this same question. Thank you!!
Why does everyone call them ELdebrock?
I get ya. Between my upbringing and my hearing I joke that english is my second language and that I don't have a first.
@@turnertruckandtractorThe stange thing is, you are by far not the only person that does it. Hear something enough times and it starts to stick to the grey matter.
lol Even Ben Alameda says Elderbrock..
They are all from Dallas just kiddin!
It will never perform well with that air cleaner on it
I was going to say the same. The inlet on that air filter looks smaller than the opening of all 4 barrels on the 500cfm carb
Holley 650 double pumper is better than that kind of carb on a 302
Please learn how to pronounce “Edelbrock.” You keep saying “el de brock.”
Jesus man it’s pronounced eDelbrock
Well aren’t you just the gift of carburetor pronunciation
English is my second language. I don't have a first LOL. Lived in Texas my entire life and it shows.