800 avs carb for a 383

[sext7366]

Ok my car is a 383 with a single plane headers forged pistons and a 230/236 cam.  My buddy has an 800 avs edelbrock but is leaving town in the morning, should I get it or look for something else?  I have heard that holleys build more power but are kinda a pain to tune.  I feel confortable messing with tuning, but was wondering if the vacuum secondaries on this 800 eddie might make it work better for a street car?

[dodge freak]

Well holley make vacuum carbs. also even in the HP series. I only had holleys no eddy's so I am not sure. The holley HP 750's flow 800+ cause it has no choke, which you really don't need with those carbs. The mettering blocks have a different idle circuit which helps out. I have hear that the eddy's carbs. don't like big cams, not sure if thats true or not.

[andyf]

I've used the Eddy 800 AVS on several of my Mopar stroker motors.  They work great and are easy to tune.  The metering rod design allows you to easily change the AF ratio at cruise vs. wide open throttle.  Here is a link to a mag article that I wrote where we used the 800 AVS.
http://www.compcams.com/Community/Articles/Details.asp?ID=2004264609

The 800 might be a tad big for your motor but since that just means that the air valve won't open up all the way at WOT.

I'm currently building a Max Wedge motor with twin 800 AVS carbs on it.  I'll have that motor on the dyno here in a few weeks.

[grouseman]

AVS is not a vacuum secondary carb.  It's an Air Valve, which opens as it is exposed to airflow from the mechanically operated secondary throttle plates.   More like the Thermoquad, AFB, and Quadrajet.  The newer carbs (TQ & QJ) have the air door opening rate damped by a vacuum pull-off for a smoother transition; the AVS doesn't.  But it still works very well. 

The original AVS carbs generally used a 3-step primary metering rod, deeper jets and a dimpled cover plate. 

[andyf]

Right, the Eddy AVS isn't really a true AVS carb if you use the old Carter naming convention.  It is a AFB with a spring loaded secondary air valve.  But Edelbrock owns the rights to the names so they can call it anything they want (and they do)!

I think a more significant difference is that the AFB used a booster venturi in the secondary while the AVS used a dump tube.  The Eddy carbs use booster venturi's which is why I consider them to be AFB's.  But the three step metering rod is another difference.  (did all AVS models have a three step?  I was thinking the early ones didn't but I'm not a Carter expert)