Holley tuning

Usually, I like tinkering with Holleys, but I'm a bit flustered with this one. Newer Holley 750 VS (3310), I bought it used and returned it back to stock, near as I can tell. I've got the clear-ish cam in the "1" spot for the accelerator pump, .015" clearance at WOT on the arm, .031 squirter. I've got nasty bog-itis with the plow on and engine warm, but it cleans out and rips the tires. I put a 35 squiter in, the bog was less. 37, the bog was more, but the tires ripped even better once it cleaned out. the 28 squirter was fairly hopeless. I started this by using the previous owners orange cam in the "2" slot, with these squirter combos. What would you guys try next?

I need to make a tool to grab the squirter and get it around the choke shaft. It's nasty being on your knees, balancing on the core support and fender, forehead on the hood, in the dark, holding a light with your chin, and the needle-nose slips and drops all that stuff onto the butterflies.

Thanks,
Pete

I would suggest being SURE of the correct amount of the "off idle" slot showing below the throttle blades when at idle. Do this by varying the idle opening on the secondary side; (the more you open the secondaries the more you will close the primaries and vice versa). The primary slot should have .030" to .045" showing below the plate and the secondaries should have no slot showing below the plate on that carb.

Normally the #218 pump cam in the number 2 hole with a .035" shooter will work fine; and get a "hollow" pump screw.

Randy,

Thanks! I had heard about the hollow screw, but figured I didn't need one yet. Now I've got an excuse to go to the local speed shop after work!

What color is the 248 cam? Or, are the numbers cast into them? I've always just referred to them by color.

Can't wait to try it out!

Thanks,
Pete

Pete, did you get this fixed, like to know if what Randy said fixed it, ive got the same problem. 750 vac. holley


Keith

I think Randy meant the 218 cam. It is white. To add, if you have to get very far away from stock, then you are probably covering up a problem from elsewhere and it isn't the carb.

fixed mine with 31shooter, 2nd hole and 50cc pump.


Keith

Need more info on your motor. What manifold, cam , vacuum @ idle etc. Many times with a big cam and open plenum manifold we had to go to the 50cc pump to eliminate bog-flat spots, but its hard to say without alot more info.