Hi all.
Here's what I've got:
1967 Camaro, 350 + .030", 4 spd, Edelbrock Performer intake, MSD 6a, mild cam (sorry, no specs), 3.08 gears.

I was a brave soul and picked up a 4165 (650 cfm s.b, v.s.) on e-bay and rebuilt it with a Holley kit.
All seemed to go smoothly, as it was a nice clean core. The one problem I'm having is that I need to turn the idle mixture screws all the way in to smooth out the idle, and I'm still only at 12" of vacum. I checked the plugs and they are pretty black..obviously too fat. I checked the pump pressure and it's o.k. at 6.5 psi.
To be on the safe side, I tore it apart again and blew out all of the passages, rechecked the float levels, but still no luck. My thoughts are:
1. The new power valve is deffective.
2. The idle needles are the wrong ones for the carb and are not seating correctly.
Any ideas?


Thanks fo rany help.

 

not much experaince on holley, but i would guess the idle needles, power valve should not be bad unless the motor has back fired though the carb. good luck

 

what powervalve are you running. the cam in my small block only has 9" of vacuum. i'm running a 3.5 powervalve and it does OK. if your running a stock valve which is usually 6.5 try getting a lower one like a 4.5

 

with the car in drive,check your vacuum,go 2 points below that.say your vacuum in drive is 6.0 then you should run a 4.0 power valve.that is what holley suggests.go 2 points below your lowest vacuum.if the back of the power valve is wet then it is bad,replace it

 

did you check elsewhere for vacuum leaks(not at the carb)? you can check your power valve by putting it up to your mouth and sucking in. if the diaphram is good, it will move. could be that your jets are too large

just throwing out a couple of ideas for ya

 

couple things come to mind that I have done wrong through the years check your power valve gasket you know the round one that goes against the metering plate . Check the metering plates for warpage make sure the little screw on the base plate that can adjust the rear butterflys is not cranked in to far (if it has on) this is a old trick you do if you have a very large cam and have idle signal problems,oh make sure you are using the correct metering plate gasket there are ones for
larger doublepumpers and VS carbs. Your choke isnt just falling shut is it ? There are 2 different lengths of needle/sets
also If I remember right there is one called a 110 that is hi flow for DP carbs and is to lone for side hung floats . Hope ya fix
it. I am not into turbos but 625 seems small to me for something you are trying to double the air input to seems like it would be restrictive