Holley 3310 Vacuum Check Ball

It had the metal cover. I read during a post search that where the ball should sit, there are small grooves to let some air bleed by. In this carb, where the ball should sit, is perfectly smooth. It looks like the ball would completly seal things off.
I put the mighty vac to the chamber inlet and I really had to pump to make the acturator rod move.
I think I will remove the ball.

Joedust, you're right. It has a 72 pri jets. My bad memory.

Maybe try a lighter spring and test drive with paper clip

You may have installed the wrong check ball, i would just run without the ball, then start with the silver/clear spring, that will be the stock one, unless your doing this on the cheap, you may want to invest in the QF vacuum pod.

QF 63-1 Adj. pod
37.11 from Quickfuel

Two steel balls came in the rebuild kit. A small one which looks like the accelerator pump check ball, and a larger one. I put the larger one in the vacuum chamber as it appeared to be the correct size.

no check ball in kits as far as I know! Back in the day I was changing vacuum springs and out went the ball down off the intake and who knows where. Anyway it seemed to work much better without. At the speed shop I asked about it and was told that is the first thing you get rid of to make a vacuum advance work right. Toss it and go on with your life if vacuum can't get to the diaphram how can it draw the secondaries open??
If they still don't open make sure the diaphram is properly positioned.

Don't need the checkball. Works fine without. Did you happen to check function of diaphram with pod removed from carb (through hole in side, using vacuum source)? Also make sure the cork gasket between pod and main body did not fall out when trying to install pod...this happens easily, but solved w/a spot or two of superglue on the gasket.

In the genuine Holley Trik Kit for 4160's there is a small plastic bag with small metal parts (E clips, cotter pins). In that bag were the steel balls.

Yup, checked operation with the mighty vac. With the ball in place, the diaphram barely moved with vacuum applied. I removed the ball and the diaphram moves much more easily.

I am leaving the ball out, as I believe now it is not required in this vintage 3310.

Not needed use the purple or yellow spring

I use DP carbs all the time and have for the last 20 years but I do work on my friends vacum carbs. The reason for the check ball was that when the vacum hole is the correct size for the vacum to apply the diaphram it will not release fast enough when you let off the gas which would cause the eng to hold a higher rpm longer then it should on decel. So the check ball would be pulled on its seat by vacum pulling the diaphram open and with the ball on the seat the vacum would go thru the slots cut along the check ball seat which should apply the secondary vacum throttle blades at the correct rate. Then when you let off the gas the check ball would unseat and open a larger hole to release the vacum to the diaphram and the throttle would close fast enough so the rpm would not take to long to return to idle. Make any sense ??? But most racers figured with the ball out the hole is bigger and it applies faster. And they would use the lighter spring also that seemed to work ok even though Holley said the secondary throttle blades would not close fast enough with the ball removed. Ron

On carbs without the "grooves" under the check ball, an old trick was to smack a small philips screwdriver in the hole to create the grooves which allowed you to run the check ball for the reasons above and allow it to open a little quicker.

According to Holley, if the vac housing has a brass pressed in restricter, no check ball is needed.

Here's my housing. No brass and no grooves

And if I did want to be dead stock, which is the correct check ball to use?

Here is the larger one - it fills the diameter and appeaars not to let much flow by.

And here's the smaller one - which I thought was the accelerator pump check ball, but now I'm not sure. It certainly would let more flow through.

Anyone want to "check" their vac housing for what ball is in there?

Looks like that unit may not use a check ball, but its really hard to tell with these older carbs sometimes, because alot of them have been messed with, if you really don't mind spending the extra $$ & your really concerned about what really needs to be in there, i would just invest in the QF Pod, its really handy, just turn a screw & adjust, that easy, i used one once on a 3310 to try it out, i liked it, more or less eliminates any confusion.

I have a 3310-11 and mine looks just like the big ball. I run the silver spring and went up to a 37 sqirter and it ran just as good as the car did with a 650 mighty demon, it idels better but after reading this I might try it with out the ball

I'm 98% sure the check ball in mine is the larger one. I had the carb on the Challenger apart last weekend to change the spring. BTW, this carb is new (2 years old).