500 cfm is not sized out of line as the Autolite 1.08 is 480 cfm and the Holley is 465. Edelbrocks seem to be over rated as to sizing anyway. The eddy is very tunable, likely the problem with poor response is the springs need to be changed to lighter to match your engine vacuum and a richer metering rod. They run reasonably well out of the box but a tuning kit really makes a difference and does not require a mechanic to "optimize" it everyday.



marv

Gary - My concern is really around my cam.  It isnt stock, its 224 deg @.050, which seems to be on the edge of suitability for many carbs (i.e. demon app chart shows 220 is the limit for the Jr)  If it was the stock cam, it would be a less risky proposition on the carbs, thus my barrage of questions!  Its too bad you are so far north and that I cant meet you in sycamore!

Marv - Ive tuned the eddy with different springs & rods, and you are right, it helped a ton.  It is still sloppy, however, and gets poor mileage compared to the holley 390 (on the order of 10-12 mpg). 

I figure since i have a credit from Jegs, Ill probably try the 465, put on electric choke, and see how it goes.  I havent really heard anyone with a reason to go to the avenger 570 thus far, except for the guy at jegs.....

Ron Grove

Wauconda, IL

The cam limitation seems to be rather general. I think the Edelbrock that you got to work is for use with 220 @ 50 or less. The demons have been used successfully with bigger cams.



I like the 570.


Lawrenceville, GA

Ron, with the mild cam that I'm running the 465 is ideal, the 600 was overkill. The 224 in yours should be able to handle the 600 easily but you'll have to call this one on your own, to bad you couldn't find a carb to borrow for some test runs. I've been with Holley for almost 50 years and very seldom have I ever had an issue.....maybe just lucky? Gary

       

Gary, 55 Vicky, St. Germain, Wisconsin

 

Dang it, Charlie!  I was settled on the 465 until you threw your vote again to the 570!  I still might try the 465 next because it will flow 18% more than the 390, and will bolt in place easily (single fuel feed, no relocation of coil, oil bath fits, etc)  Still not 100% decided though...

Gary, you say you have a mild cam.  Do you happen to know the specs?  Everyone (articles, etc) refer to "mild" cams, but i dont have a point of reference as to what specs are mild vs. aggressive? 

Thanks to all for the input and patience.  In case you havent figured it out yet, I tend to overanalyze things....

Im trying to get this decided in the next fvew days so I can send the demon back to Jegs before we go on vacation to AZ for 2 weeks, so hopefully I can come home to my shiny new carb!

Ron Grove

Wauconda, IL

Well, like I said, you can get opinions and advice all day. You just gotta try it.

The 465 did very well on the carb dyno test and a Street Avenger was not tested. So, the 465 is a safe bet.


Lawrenceville, GA

Charlie, was the dyno test you refer to something here or elsewhere? Any idea where I could find it; I tried a forum search and didn't find it...

Thanks!

Ron Grove

Wauconda, IL

It is in the last issue of Y-Block Magazine.

If I remember right, it came in 3rd, after a modified Holley 600 and a Speed Demon 650.


Lawrenceville, GA

i know you cant buy them new but the autolite 4100 remains my favourite.

Ron, I have a RV cam, it's around 210>215 @ 50, it's a lower end cam, ideal for cruising but loses some on the top end. 75 on the interstate isn't a struggle but on a trip up to northern Minn. to a show I was in the 18 mpg range so I'm happy with it. Gary

       

Gary, 55 Vicky, St. Germain, Wisconsin