Carb advice

[Paul619]

I am having a heck of a time tuning my carb. It is a 600cfm Vac Sec. I finally have the plugs looking like I want them and it does pretty good in the low end. I have the main jets and a s stage power valve right about where i want them now it is time to get the secondairies going. I have a flat spot around 3000rpm and I cant seem to get rid of it. I am running a smaller check ball in the vac sec. and it has the bare metal spring in it. it feels like they are not opening fast enough. I have reamed out the sec. jets on the metering plate and that made a difference (holley and their no adjustment for the secondaires ha) definitly pulls hard about 4 grand up to 5500 but if I had the extra 1000 revs out of the mid range I think it would fel alot better. no matter how you are driving it does it at the same spot too. From a dead stop or rolling even worse in 3rd gear though trying to pull through the revs. and that is right about the 60- 80 range and just doesnt want to move i hae the timing set at 36-37degres total(dont know what the initial is right now but i bet is it close since i hae no low end problems.) I have trick flow heads and tri ys weiend manifold msd roller rockers and a cam with .540 total valve lift and a duration of 240 if you have any ideas or if anyone in san diego can help me out I wil definitly be gracous

tia
Paul

 

[rbohm]

use a lighter secondary spring to get the secondaries opening quicker, and a heavier spring to slow them down.

 

[D.Hearne]

You need a bigger carb. I'd also remove that check valve. I don't recall ever seeing one on my old 600. If you've got a manual trans, consider stepping up to about a 700 cfm carb. With your setup, it ought to pull to 7 grand at least.

 

[Paul619]

You need a bigger carb. I'd also remove that check valve. I don't recall ever seeing one on my old 600. If you've got a manual trans, consider stepping up to about a 700 cfm carb. With your setup, it ought to pull to 7 grand at least.

i dont think i want to try to have my car spin 7 grand on stock rods still havent gone through the bottom end

 

[Paul619]

well i went to the white spring and it made it worse I guess that it is getting too much fuel in the mid range and it just bogs so i guess holly was right in what they wrote i guess now i will try the stiffer spring