350 pontiac

[cris85]

hello, i'm french!
my English is not very good!
i have two firebird!
a 1968 firebird convertible 400/th400 and a 1978 firebird with a 1970 350 pontiac engine!
i need help finding the right calibration of my carb , it's for the 1970 350 pontiac engine.
i have edelbrock intake, an aac k2801
(Intake Duration at 050 inch Lift,
214 Exhaust Duration at 050 inch,Lift 224
 Duration at 050 inch Lift   214 int./224 exh.
Advertised Intake Duration      272
Advertised Exhaust Duration      282
Advertised Duration      272 int./282 exh.)
dual exhaust, cr 9.5, power brake, th350

i have a 1968 rochester quadrajet 7028264.
i want a street application!
can you help me? ( idle tube, idle down channel  restriction, ...)
regards
chris

[Cliff Ruggles]

Chris, do you have one of our books?

Without typing many pages here, it is well explained in our book......Cliff

[cris85]

yes, off course, i have your book!
but i want your opinion.
i make it:
idle tube:0.37
idle down channel:0.55
upper idle: 0.50 ( air horn)
down idle: 0.70
idle bypass:0.80
mixture screw: 0.96
primary met.:i buy it on your sit
sec met.: i buy it
main jet: 0,73

i try it, but i'm not sure, because the car start very well, i can adjust idle very well but after, she make a bad reaction: when i accelerate gently, i have hole! i think she takes too much gas !!!
i want to install back the original primary and secondary met. and jet?
thanks

[65WildCat]

[when i accelerate gently, i have hole!]

Make sure you secondary air flap spring tension is not set too loose...

[cris85]

i'm sure the secondary air flap spring tension is not set too loose!
the problem is not when I accelerate hard, but when I accelerate just a little!
I try to post a video

[Cliff Ruggles]

It may be slightly lean.  Have you performed the "tip-in" test as described in our book?......Cliff

[cris85]

I have not done  the  "tip in" test, what is  this number page?
for information, I made only one lap to settle the wealth
thanks

[65WildCat]

Tech Tip - Tip In Procedure - Page 99

[cris85]

ok, thank you all already, I solved one  of the problems, the hesitations came from  the  depression  of the igniter! but how to prevent  this?
it smelled strongly of gasoline!
and I have no acceleration pump, no small jet fuel! it must be just the float level!

i make the tip in test, but i do not see anything  special

thanks

[Cliff Ruggles]

No accellerator pump shot, common problem these days. 

Did you install one of our rebuild kits with the tuning changes?

Our kits contain upgraded components, the accl pumps are much better than the factory parts that carburetor used.

At a minimum, install one of our SR kits, and set the float to exactly 1/4"......Cliff

[cris85]

thanks cliff!!
ok for the kit, i think it's only float level problem!
but the vacuum advance, how can i do ?

[cris85]

no news?
it's impossible to connect the vacuum advance!!!
how can i do?
thanks

[Cliff Ruggles]

Set the float to exactly 1/4".

Is the accellerator pump working or not?

The vacuum advance port on those carbs should be in the front of the main casting, drivers side, just to the right of the fuel filter housing.....Cliff

[cris85]

thanks cliff!
I know where is the location on the carburetor, thank you!
the concern is that the suction created is an adverse effect, and sucks when it's connected intermittently (sucks, stop, sucks, stop) and the advance does the same! and the engine is running, stop running, stop!
idle, it goes. the middle was the problem. and bottom, that's ok!
is it a problem of spring in the ignition?

[Cliff Ruggles]

There shouldn't be any vacuum at that port at idle speed.  The throttle plate angle is too high.  It may need more idle fuel, or more idle bypass air, or both......Cliff