Jeff Smith's Garage Edelbrock AVS2 Carb review

[Music] hey how you doing welcome to another episode of Jeff's mist garage today we will be talking about the Edelbrock ABS 2 carburetor they come in both 500 and 650 CFM packages but I want to tell you what abs stands for just because some people don't know air valve secondary it's actually refers to little valve on the secondary side that so that you don't have it's a mechanical secondary carburetor but there's no squirter on the secondary because the air valve door does that for you the the key to this carburetor the ABS too is an angular booster and that's we're going to talk about [Music] so a vs2 is a little bit different and they've changed the booster design on this carburetor and they've gone to an angular discharge booster we'll get into that in a minute but I want to give you some of the other features in this carburetor so it's really very cool I think this is one of the more simply adjustable street carburetors on the market today I'll show you why that is so right away right away idle mixture screw idle speed idle speed is set over here typical of a any kind of a carburetor what makes a little bit easier is idle mixture screws are right there in front real simple to do really simple to access where it gets where one of the advantages of this carburetor is is is its adjustability without having to take the lid off the carburetor so one of the features of this carburetor is they use and this little I'll show you a little detail later but there's a and a little door right here you just take a screw loosen it up move the door off and immediately what you get is a power piston metering rod and a spring is accessible from the top of the carburetor and one of the advantages is if you want to try and do part throttle tuning on this carburetor it's very easy to do you move move this little screw move that little door all the way this stuff all pops out and one of the simplest quickest way to tune this carburetor would be to possibly change the power valve spring so what happens is that part throttle this spring is pushing upward on the metering rod and being held in the Pistons being held down by vacuum so at high vacuum it compresses the spring as the load starts to go away the spring starts to move the metering rod up to give it more fuel yeah you can't see it from there but there's a taper to this metering rod so the metering rod is changeable but one of the quickest ways is with the spring so one of the things that you can do is go to this is actually there are I think there's five different Springs this is the middle placed one this is the orange spring so if you want to do a slightly lighter spring than which would be I think the yellow spring it will hold the metering rod in the jet a little bit longer as the load increases and it allows you to improve your fuel mileage we had a situation a friend of mine called me up one day and he says I've you know I've got this small block in I'm with like a 273 gear and he dykes to drive fast on the freeway to go along long trips the fuel mileage just killing me what can I do and I said well try changing this little spring get a tune-up kit from Edelbrock and try and change the spring we went from the orange spring to a yellow spring and he was in how heavy his foot is he was in single digit fuel mileage on a small-block Chevy going down the road about 80 85 miles an hour went to one step lighter on the spring that kept the metering rod in the jet and his fuel mileage went to double digits I think it went from 8 to like 12 so let's talk about the real main feature of this carburetor the ABS too so we've taken all the screws out of here the lid comes right off take it out of the way and the boosters are all removable this is really the key to it right in here the whole trick to this whole carburetor is inside this booster right here a typical standard booster uses a single outlet that they only use the anglers on the primary side in this carburetor the secondary side there's just a single outlet to it when you go to the angular booster then there are actually eight very small little holes around the circumference of the inside of the booster and what that does is it introduces the fuel in a much more vaporized States and now you have eight outlets smaller outlets which tend to break the fuel up what you're looking for is you're looking to turn the fuel from a liquid into a gas as soon as possible to vaporize it that that's the common term so what you because vaporized fuel burns liquid fuel doesn't [Music] so the test I wanted to do was I had one of these carburetors on a small-block Chevy with a 4l60e behind it and what we decided to do was we had a standard typical Holley carburetor on there and I just judged throttle opening based on the TPS and at light throttle it intended to accelerate like he wouldn't normally away from a stoplight no burning the tires or anything about eight to ten percent of throttle opening and and then I changed and all I did was both on an ABS to set the idle mixture screws and set the idle speed so it was the same as the previous carb air went out drove it around and looked at it and essentially what was happening was we were going from let's say from 8 to 10% throttle opening to 8 to 6 percent throttle opening so if you think I think well it doesn't sound like very much but in reality if we're going from 10% throttle opening to 8% throttle opening at the same acceleration rate that's a 20% reduction in the throttle position so what was happening is thing was much crisper and you'll notice this u-bolt with these carburetors on the very first thing first time you drop the thing in gear and touch the throttle you will feel it it's it's it's like it's almost like it's a fuel-injected car we did another test a long time ago on angular boosters versus standard drop leg boosters and we saw what we saw was the typical we loaded an engine at a thousand rpm out at Kennedy dollars shop and at a thousand rpm the engine wasn't very happy with a standard booster style carburetor then we went to an angler do booster we picked up 90 foot-pounds of torque at a thousand rpm and that was all because it was vaporizing it was conditioning the fuel better so what's happening was we didn't change the amount of fuel we just changed the way it was introduced into the engine and what we saw was an amazing difference in how the engine felt now had we taken that those and put it on a car and drove it we would have seen exactly what I'm talking about here better throttle response now once you get to fifty percent or a hundred percent throttle opening then that effectively doesn't about roughly about peak torque the crossover is such that you won't know any difference but since your typical street car is driven 98% of the time unless you're some crazed me yeah you're gonna drive around roughly 98% of time at under 20% throttle opening that's where this carburetor really shines and that's why it's a good style [Music] you

Channel: bentymedia

Views: 121,931

Keywords: Jeff Smith, Smith, Edelbrock, Edelbrock carb, technical, carburetor, engine tuning, Edelbrock AVS2 Carb, AVS2 carb

Id: tbRqRfDHKYI

Length: 7min 14sec (434 seconds)

Published: Tue Aug 14 2018