turboitall

i have a 1985 ford mustang gt. its a monster, nothing is stock. i cant get the carburetor tuned right and im completely out of ideas. here are the specs:
302 bored .030 over
10:1 compression
world windsor sr heads (64cc chambers, 2.02/1.60 valves), heavily ported.
ford racing x303 hydraulic roller cam, 1.7 roller rockers (.578 lift exhaust and intake, 224 duration @ .050)
edelbrock victor jr intake (single plane, high rise)
full msd ignition, digital 6-plus box.
18 degrees initial timing.
holley blue fuel pump, 3/8 aluminum fuel line, aeroquip a/n fittings.
110 octane racing fuel.
T-5 manual trans, 3.73 posi rear end, aluminum driveshaft.
and finally the problem, a proform 650 carburetor.

the primary jets are #72, secondary - #80 with jet extensions, power valve - #75 (vaccuum tested with 13 - 15 hg), primary and secondary nozzles - #31
idle air bleeds - .073", high speed bleeds - .036"
idle feed restricters - .031"

the problem i am running into while driving is if i press the throttle half way (just before the secondaries open and the primaries are wide open) the car loses power and it jolts but i can give it more gas and it goes right past it. it also does the same thing during WOT only at 6200 rpm and up. i need to shift at 6800 - 7000 rpm, everything is set up to make power up to 8000 rpm. by jolting i mean it stops accelerating and makes a "zzzzzz" or humming sound. i assume that its leaning out but larger secondary jets have not helped.

also, when i am starting to move from a stop i have to rev it up kinda high or else it will stall out. but i fixed this problem by playing around with the air bleeds, i switched one of the idle bleeds with a high speed bleed and it drove beautifully. i switched it back because i dont think that is the proper way to fix the problem. plus, that did nothing for the jolting at high rpm.

so now i am at a loss and i need someone to tell me what to do. any suggestions?

turboitall

no one has any clue??? i talked to quickfuel and they said to try smaller squirters. i am not sure how that will help up top but i guess ill try it. does this make sense to anyone? any other suggestions?

Grimace5.0

Because the squirters you have are puting out too much volume.

My engine is not much different from yours. I just talked to Barry Grant last week and they advised me to run:

Front squirter-28
Rear- 31

Front jets -72
Rear- 80

Is the accelorator pump in spec? What accelorator pump cam are you using? Everyone I've talked to said to use the pink one.

Grimace5.0

And change one thing at a time and test it. Don't change a bunch of stuff, you'll chase your tail forever.

JD1969

All those things only affect the enrichment circuit in the carb, squirter size and accelorator pumps and cams do nothing at part throttle and WOT. I have been thinking about the problem and have not really come up with mush other than possibly your fuel pump not keeping up. Holley blues are not really very good, it took two to feed the 355 in my Nova, and you motor looks similar. I doubt thats your problem though but you might want to check it anyways, you do have a fuel PSI gauge right?

ballstix

Is it a double pumper? Also I dont know if the fuel pump would effect that because you should be able to run up to a 750 with a mechanical fuel pump.

vfast

after reading I still don't know what carb you have...
if I knew I can solve this for you....what cam is on the linkage?.
what acc. pumps?
is the air horn milled?
also the linkage for the other 2 barrel needs a lil adjustment to come in

93notchbac

mite be your secondary accelorator pump not working that will cause a loss in power but will pick back up if you stay in the gas, that will also cause it to lean out for a split sec,

JD1969

From what I get V he has a Holley 650 with the Proform center body.

vfast

it's vac secoundary? or speadbore?