[Guest]

I need some help from the hot rod cleveland guys out there. I have a 70 mach 1 that I just finished a engine build on and I need some help matching a carb to my motor. The engine consist of a .030 over D0AE 351C with TRW pistons, closed chambered 4V heads with stainless valves, .539 lift 278 dur. Hyd. crane cam, Hooker super comps, and a single plane Torker intake. I have a Holley 750 w/vac secondarys on the engine now and it seems to run good, but its not very responsive off the line. I'm afraid to go with a 650 CFM carb. because I don't know if it will flow enough cfm for the big port cleveland on the high rpm side, and I think a 800 cfm will just be to much fuel on the low end. Please let me know your ideas. The car has a toplaoder 4spd and 3.50 rear gear that may change to a 3.73, 3.91, or 4.11 soon. I want to be able to burn a wheel without dipping the clutch, but still have the car pull hard up to 6000 RPM. Is this possible? Thanks

 

[mod9]

Sound like you just need to do a little tuning on your carb. Check jetting to make sure it is fine. If that is ok you may want to play with the accelerator pump cam,secondary opening spring and the squirter size. Also make sure that power valve is not blown. A little tuning on a holley really helps. Good Luck

 

[Art]

Either a 700 or 750CFM double pumper... With a 4:11 gear, you should be able to light them up easily in 1st, 2nd, and maybe 3rd.

That combo should allow the engine to rev to 6500-7000 RPM easily.... The old Holley Strip Dominator intake was the ultimate Cleveland intake, (IMO). If you spot one cheap, grab it!

 

[camachinist]

Your carb is fine for the application and just requires some tuning, likely in the idle/intermediate circuit and accelerator pump areas...

Main problem is 4V heads and 3.50 gears....4V Clevelands were made to operate in the 3500-6500+ range and can be a bit doggy on the bottom end, especially with a streetable CR, the cam you've chosen and single plane manifold.

Personally, I'd keep the carb, add a secondary idle circuit and 50cc pump, change the rear gearing to 4.11 and tune the suspension to handle the increased torque load in the lower gears. You might also experiment with plenum dividers...I had good luck with them on single plane manifolds on the little engines in the race car

Street cars have many compromises, as you're now finding out...

Good luck!

 

[sidewinder]

Make sure that your timing is coming in soon like 2800 RPM. Don't put too light of a spring in your secondarys some where around the middle spring in the kit.