[eric32]

Hello guys a different subject here. I got a reman holley 670 street avenger off of ebay from a company called allstate carburetors and I did some research and they seem to be really good.

Anyways I got my carburetor today and it looks like a brand new carb but I have a few concerns and I hope there is nothing wrong with it. I have put up some photos and there is a white powdery stuff all over the carb and its really noticeable inside the tower.

Is this just from some sort of stuff they use to polish the carb or something and its left over or what? I notice all holley carbs when purchased brand new they are all like that but mine has a lot on it.

I took it apart and the metering blocks seem to look the same as also inside the fuel bowls. Also under the base plate on the bottom they seem to have installed an air bleed of some sorts right in the middle and why would that be there?

I have never seen a holley carb with an air bleed there and all of my other carbs I have ever had just had the little hole there. Hope some once can let me know.
Thanks
Eric

[spinn]

Air bleed in the center of the x has been there a while. The 600 has one on my 323 mopar single plane . Hollies need to make sure they can provide the correct fuel at idle. Some idle bleeds are too small for modern fast ramp/high lift cams.

Hollies are hollies. Fine for the drag strip or WOT. Cruising the perferred unit is the Q-jet or AVS/AFB. The needle obstruction in the jet really increases performance down low, stabilizes even fuel flow, and stimulates velocity for awesome acceleration. Right from the hit.

If you have a 350/383 the 750cfm carb fits perfect. Be it a 750 QJet or 750 vacuum secondary holley with stiff spring ,or 750 edelbrock. Out of the box they seem right. You never use the full cfm in the secondaries anywho. The performace comes from the primary side, the secondaries help past 2/3 throttle, and then do not flop open. The engine pulls against the spring, in a struggle to get enough air to meet the fuel ratio.

[eric32]

Well they must have quit putting air bleeds in the middle of the base plate a long time ago cause on my 600 holley I have and two others I have cam across there was none.
I also got a spare 600 a couple of months ago and it has the same base plate, tower, metering blocks as the holley 670 street avenger and none of them has an air bleed on the base plate at the bottom.

I don't like the fact of it being there as it could vibrate loose and fall out into the motor. I am going to just take mine out and leave it. I am not running a big cam or anything and my other holleys ran fine. It seems the hole is the same size as my other base plates.

Also I never knew the base plate has any affect on idle mixture from reading all of my holley books from that center mark.
Eric

[pepi]

Just me maybe but that looks rough, or your pictures are deceiving me. The venturi looks like the air will have a bumpy ride on its way in , or is that hollys idea of pre atomization?

[eric32]

Well just for the heck of it I called Allstate and man they where very nice and answered all my questions about the stuff. It is as I suspect left over zinc plating compound and he said its really hard inside the tower to get it really shiny and with no left over compound but said it wont hurt anything.

And as far as the brass air bleed in the bottom of the base plate that is there for the purpose of if you are running a big duration cam you can just drill the inside of the stud tower and make it function like a barry grant idleze and change the amount by changing out the air bleed but he said it is non functional at the moment.

So I am just going to leave it out since I don't need that type of a feature anyways. I am running mild cam in my engine. Thanks guys for tips.
Eric