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-   -   carb tuning quickfuel 950 pro series carb (https://www.racingjunk.com/forums/showthread.php?t=25906)

mtalp 10-01-2009 05:00 PM

carb tuning quickfuel 950 pro series carb
 
To anyone that can help, I an a novice at tuning a carb and would like to find a good carb tuner in new jersey atco . If there is anyone that could help i would be great ful

Scooterz 10-05-2009 02:34 PM

I have this carb myself... although I do not consider myself an expert, I do know it's nature & quirks.

First, tell us your setup.

tell us your use/application as well.... just a race car?

Last, I have only had to jet mine for my application & adjust it beyond that... it was adequate out of the box. came w/ three linkages, I used the mid linkage...just had to jet up in primary due to altitude here.

Got a vacuum gauge? The carb you have has been an awesome upgrade for me (had a 850 Holley DP)! I gained secondary idle adj, windows, jet extensions, PV block, etc... I like how you can turn the F/A screws by hand too on 4 corners. Let me know what specifically you need & I will answer what I can.

mtalp 11-20-2009 03:50 PM

950 quick fuel carb
 
Hello , i am running a 540 bbc on 93 octane {pump gas} . the engine has 9.6:1 comp. flat top piston , cam is isky solid roller .313 dur./ .730 lift . /. 276 @.050 . 110 centerline . cam is degreed at 106.375 of a degree. i am using brodix bb-2 pluss heads that are poRted and flowed at .700 lift int is 377 exh at .700 lift 277 . intake is brodix hv 2000 4150 flanged and carb is a quick fuel 950 mech . secondary . pro series 80 jets in primary 86 in secondary # 45 pv in primary secondary is plugged my problem is at idle at 1000rpm in park vacum is only 3.5 inchess and in gear i have o . I wonder why there is o vacum in gear at idle? Icalled isky and they say i should have at leat 8 inches of vacum in park . thE car is a back halve 67 camaro with a turbo 400 manually shift w ith a coan 10 " 3800 stall convertor. with a dana 60 wit 4.10 gearing .I also locked out the distributor at 34 degrees and brought the idle up to1350 rpm. The plugs are autolite #3924 and gapped at .030 [MSD 6-AL BOX IN CAR]How much timing should i run ?This is a street and strip car .

jmarksdragster 11-20-2009 06:51 PM

Where is the timing at?

jmarksdragster 11-23-2009 07:37 AM

It would be better to lock out the timing to full advance, it will improve idle vacuum and throttle response. With that much cam, you also need more converter. N/A I would look for a 9" that stalls 5000, maybe a little more.

Pwmax 12-19-2009 05:36 AM

I second that. I always lock the distributor in big cam applications like that. Its amazing how much better they run. With the low compression, and big duration, and moderately tight lobe sep, that thing isn't going to have that much vacc. anyhow. 5 or 6 max. 8 would be maybe at 1400 rpm. Not sure where your idle rpm is set, but that will have an effect on vacc too. If you are trying to idle it at 800 rpm, vs 1000, etc. Guys always seem to try and want to run the idle speed to low on engines like this, and think its their daily driver truck, and it should idle at 650. It won't. 1000 rpm is probably going to be the lowest happy rpm you will be able to run it. My question, why are you worried about vacc? Brakes or something?

back on the original, once you lock the timing, it will also give you WAY more control over the carb. What happens many times on bigger engines, is, you don't have enough idle air, so, you open the throttle blades way open, to get it to idle at a decent rpm, then, you lost all control of the idle circuit. Cranking the timing, will rev the engine up, then, you can back the idle screw and restore the proper transfer slot relationship, and have control again of your idle mix screws. It won't ping or detonate locked out either.

Frank


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