New Holley Street Avenger Carb Question

I'm considering purchasing a new Holley 670 Street Avenger carb. I see Summit has this carb. in part number 80670 and 83670. Doing a side-by-side comparison it looks as though they are they same with the exception that the 83670 is aluminum. However, the aluminum version is $26 cheaper. I would have that the aluminum would have cost more. Does anyone have any experience with these carbs. and if so, is an aluminum carb. a pro or con?

I have never and I mean NEVER seen one of those carbs run correctly. Avoid. J.Rob

Are you referring to just the 670 version or any Street Avenger carb.? I have had a 770 Street Avenger on my car for nine years and it has run perfectly from day one.

I hope you buy lottery tickets because I have never seen ANY Avenger series carb run properly. In fact I have had many come in for dyno testing and we cannot even perform one safe pull. You can play with jetting all day and it won't make a difference. Something is messed up with the metering blocks and I have never looked into as time is $$$. J.Rob

p.s. I bet if you put a regular and known good double pumper on you would see what you have been missing out on.

No reason to change carbs as I'm not missing out on anything. I couldn't expect the car to run any better than it does. I also know someone running an 870 Avenger on their car and it's the same thing, no issues at all right out of the box. And yes, I do buy lottery tickets. No luck so far.

The Idle restriction and power valve restrictions in the metering blocks are smaller/leaner than most carbs. Mine would go lean in the transition range until I opened up the idle restriction.

Sounds exactly like the issues with the Edelbrock 1407/1411 carbs

Why waste your time playing with those two carbs when there are so many better options out
there

I ran the 670 SA on a mild 383 in my Charger for years. Bought it brand new in about 2008. Car ran OK but always had a part throttle surge and slight hesitation problem. Could never get rid of either one. Car was in storage for a few years so I ordered a rebuild kit to freshen up the carb. Now it won't run at all. Put my old Eddy competition series 750 on the car and runs fine. I like Holley but I would not get another Street Avenger. Frank

In a carb test run by Dunnuck a couple of years ago, the 670 Street Avenger was the farthest off and the most difficult to tune of the carbs they tested. The best was the Holley Street Demon. Nearly perfect out of the box, IIRC. For some reason the 670 is the red headed stepchild of the Street Avenger series. My 570 was up 2mpg over the Holley 1850 that had been jetted down for altitude. It was a really good carb.

The Street Demon with the space age plastic bowl is reminiscent of a Thermoquad, and is probably the latest design you can find. It will bolt on your square bore intake with no adapter. They don't cost too much, either.

R.

IMHO...
There is no such thing as a perfect carburetor...
Every engine is different (compression, intake manifold, cam specs) and it takes patience and experience to dial the carburetor in. A Holley is very simple to tune, its just isolating the problem area and then making the appropriate tweaks...

To me the basic problem today is that there are fewer & fewer experienced guys with carburetor experience..

Just my $0.02...

I had a 770 SA on a 440 that pulled only about 7 inches of vacuum at 1000 RPM. Straight leg boosters and all, the fuel curve actually worked well, better than alot of other Holleys. Needed to be a little extra rich for best power at WOT (11.8ish), but the car ran decent.

So true........

The Street Demon is the $hit. At least for street cars. Has worked very well on every street combo that I have installed one on so far.

Getting ready to put one on another 440 soon.

I had a 670 SA on my mild 340 for a minute. The idle circuit on it was waaaay lean. Sucks to have to drill holes in a brand new carb not built for that level of tuning.